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linux/drivers/i2c/busses/i2c-npcm7xx.c
Uwe Kleine-König e190a0c389 i2c: Convert to platform remove callback returning void 
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Alain Volmat <alain.volmat@foss.st.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Acked-by: Jochen Friedrich <jochen@scram.de>
Acked-by: Peter Rosin <peda@axentia.se>
Acked-by: Vadim Pasternak <vadimp@nvidia.com>
Reviewed-by: Asmaa Mnebhi <asnaa@nvidia.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: Chris Pringle <chris.pringle@phabrix.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Reviewed-by: Tali Perry <tali.perry@nuvoton.com>
Reviewed-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
2023-06-05 09:47:37 +02:00

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// SPDX-License-Identifier: GPL-2.0
/*
* Nuvoton NPCM7xx I2C Controller driver
*
* Copyright (C) 2020 Nuvoton Technologies tali.perry@nuvoton.com
*/
#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/debugfs.h>
#include <linux/errno.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/iopoll.h>
#include <linux/irq.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
enum i2c_mode {
I2C_MASTER,
I2C_SLAVE,
};
/*
* External I2C Interface driver xfer indication values, which indicate status
* of the bus.
*/
enum i2c_state_ind {
I2C_NO_STATUS_IND = 0,
I2C_SLAVE_RCV_IND,
I2C_SLAVE_XMIT_IND,
I2C_SLAVE_XMIT_MISSING_DATA_IND,
I2C_SLAVE_RESTART_IND,
I2C_SLAVE_DONE_IND,
I2C_MASTER_DONE_IND,
I2C_NACK_IND,
I2C_BUS_ERR_IND,
I2C_WAKE_UP_IND,
I2C_BLOCK_BYTES_ERR_IND,
I2C_SLAVE_RCV_MISSING_DATA_IND,
};
/*
* Operation type values (used to define the operation currently running)
* module is interrupt driven, on each interrupt the current operation is
* checked to see if the module is currently reading or writing.
*/
enum i2c_oper {
I2C_NO_OPER = 0,
I2C_WRITE_OPER,
I2C_READ_OPER,
};
/* I2C Bank (module had 2 banks of registers) */
enum i2c_bank {
I2C_BANK_0 = 0,
I2C_BANK_1,
};
/* Internal I2C states values (for the I2C module state machine). */
enum i2c_state {
I2C_DISABLE = 0,
I2C_IDLE,
I2C_MASTER_START,
I2C_SLAVE_MATCH,
I2C_OPER_STARTED,
I2C_STOP_PENDING,
};
#if IS_ENABLED(CONFIG_I2C_SLAVE)
/* Module supports setting multiple own slave addresses */
enum i2c_addr {
I2C_SLAVE_ADDR1 = 0,
I2C_SLAVE_ADDR2,
I2C_SLAVE_ADDR3,
I2C_SLAVE_ADDR4,
I2C_SLAVE_ADDR5,
I2C_SLAVE_ADDR6,
I2C_SLAVE_ADDR7,
I2C_SLAVE_ADDR8,
I2C_SLAVE_ADDR9,
I2C_SLAVE_ADDR10,
I2C_GC_ADDR,
I2C_ARP_ADDR,
};
#endif
/* init register and default value required to enable module */
#define NPCM_I2CSEGCTL 0xE4
/* Common regs */
#define NPCM_I2CSDA 0x00
#define NPCM_I2CST 0x02
#define NPCM_I2CCST 0x04
#define NPCM_I2CCTL1 0x06
#define NPCM_I2CADDR1 0x08
#define NPCM_I2CCTL2 0x0A
#define NPCM_I2CADDR2 0x0C
#define NPCM_I2CCTL3 0x0E
#define NPCM_I2CCST2 0x18
#define NPCM_I2CCST3 0x19
#define I2C_VER 0x1F
/* BANK 0 regs */
#define NPCM_I2CADDR3 0x10
#define NPCM_I2CADDR7 0x11
#define NPCM_I2CADDR4 0x12
#define NPCM_I2CADDR8 0x13
#define NPCM_I2CADDR5 0x14
#define NPCM_I2CADDR9 0x15
#define NPCM_I2CADDR6 0x16
#define NPCM_I2CADDR10 0x17
#define NPCM_I2CCTL4 0x1A
#define NPCM_I2CCTL5 0x1B
#define NPCM_I2CSCLLT 0x1C /* SCL Low Time */
#define NPCM_I2CFIF_CTL 0x1D /* FIFO Control */
#define NPCM_I2CSCLHT 0x1E /* SCL High Time */
/* BANK 1 regs */
#define NPCM_I2CFIF_CTS 0x10 /* Both FIFOs Control and Status */
#define NPCM_I2CTXF_CTL 0x12 /* Tx-FIFO Control */
#define NPCM_I2CT_OUT 0x14 /* Bus T.O. */
#define NPCM_I2CPEC 0x16 /* PEC Data */
#define NPCM_I2CTXF_STS 0x1A /* Tx-FIFO Status */
#define NPCM_I2CRXF_STS 0x1C /* Rx-FIFO Status */
#define NPCM_I2CRXF_CTL 0x1E /* Rx-FIFO Control */
#if IS_ENABLED(CONFIG_I2C_SLAVE)
/*
* npcm_i2caddr array:
* The module supports having multiple own slave addresses.
* Since the addr regs are sprinkled all over the address space,
* use this array to get the address or each register.
*/
#define I2C_NUM_OWN_ADDR 2
#define I2C_NUM_OWN_ADDR_SUPPORTED 2
static const int npcm_i2caddr[I2C_NUM_OWN_ADDR] = {
NPCM_I2CADDR1, NPCM_I2CADDR2,
};
#endif
/* NPCM_I2CST reg fields */
#define NPCM_I2CST_XMIT BIT(0) /* Transmit mode */
#define NPCM_I2CST_MASTER BIT(1) /* Master mode */
#define NPCM_I2CST_NMATCH BIT(2) /* New match */
#define NPCM_I2CST_STASTR BIT(3) /* Stall after start */
#define NPCM_I2CST_NEGACK BIT(4) /* Negative ACK */
#define NPCM_I2CST_BER BIT(5) /* Bus error */
#define NPCM_I2CST_SDAST BIT(6) /* SDA status */
#define NPCM_I2CST_SLVSTP BIT(7) /* Slave stop */
/* NPCM_I2CCST reg fields */
#define NPCM_I2CCST_BUSY BIT(0) /* Busy */
#define NPCM_I2CCST_BB BIT(1) /* Bus busy */
#define NPCM_I2CCST_MATCH BIT(2) /* Address match */
#define NPCM_I2CCST_GCMATCH BIT(3) /* Global call match */
#define NPCM_I2CCST_TSDA BIT(4) /* Test SDA line */
#define NPCM_I2CCST_TGSCL BIT(5) /* Toggle SCL line */
#define NPCM_I2CCST_MATCHAF BIT(6) /* Match address field */
#define NPCM_I2CCST_ARPMATCH BIT(7) /* ARP address match */
/* NPCM_I2CCTL1 reg fields */
#define NPCM_I2CCTL1_START BIT(0) /* Generate start condition */
#define NPCM_I2CCTL1_STOP BIT(1) /* Generate stop condition */
#define NPCM_I2CCTL1_INTEN BIT(2) /* Interrupt enable */
#define NPCM_I2CCTL1_EOBINTE BIT(3)
#define NPCM_I2CCTL1_ACK BIT(4)
#define NPCM_I2CCTL1_GCMEN BIT(5) /* Global call match enable */
#define NPCM_I2CCTL1_NMINTE BIT(6) /* New match interrupt enable */
#define NPCM_I2CCTL1_STASTRE BIT(7) /* Stall after start enable */
/* RW1S fields (inside a RW reg): */
#define NPCM_I2CCTL1_RWS \
(NPCM_I2CCTL1_START | NPCM_I2CCTL1_STOP | NPCM_I2CCTL1_ACK)
/* npcm_i2caddr reg fields */
#define NPCM_I2CADDR_A GENMASK(6, 0) /* Address */
#define NPCM_I2CADDR_SAEN BIT(7) /* Slave address enable */
/* NPCM_I2CCTL2 reg fields */
#define I2CCTL2_ENABLE BIT(0) /* Module enable */
#define I2CCTL2_SCLFRQ6_0 GENMASK(7, 1) /* Bits 0:6 of frequency divisor */
/* NPCM_I2CCTL3 reg fields */
#define I2CCTL3_SCLFRQ8_7 GENMASK(1, 0) /* Bits 7:8 of frequency divisor */
#define I2CCTL3_ARPMEN BIT(2) /* ARP match enable */
#define I2CCTL3_IDL_START BIT(3)
#define I2CCTL3_400K_MODE BIT(4)
#define I2CCTL3_BNK_SEL BIT(5)
#define I2CCTL3_SDA_LVL BIT(6)
#define I2CCTL3_SCL_LVL BIT(7)
/* NPCM_I2CCST2 reg fields */
#define NPCM_I2CCST2_MATCHA1F BIT(0)
#define NPCM_I2CCST2_MATCHA2F BIT(1)
#define NPCM_I2CCST2_MATCHA3F BIT(2)
#define NPCM_I2CCST2_MATCHA4F BIT(3)
#define NPCM_I2CCST2_MATCHA5F BIT(4)
#define NPCM_I2CCST2_MATCHA6F BIT(5)
#define NPCM_I2CCST2_MATCHA7F BIT(5)
#define NPCM_I2CCST2_INTSTS BIT(7)
/* NPCM_I2CCST3 reg fields */
#define NPCM_I2CCST3_MATCHA8F BIT(0)
#define NPCM_I2CCST3_MATCHA9F BIT(1)
#define NPCM_I2CCST3_MATCHA10F BIT(2)
#define NPCM_I2CCST3_EO_BUSY BIT(7)
/* NPCM_I2CCTL4 reg fields */
#define I2CCTL4_HLDT GENMASK(5, 0)
#define I2CCTL4_LVL_WE BIT(7)
/* NPCM_I2CCTL5 reg fields */
#define I2CCTL5_DBNCT GENMASK(3, 0)
/* NPCM_I2CFIF_CTS reg fields */
#define NPCM_I2CFIF_CTS_RXF_TXE BIT(1)
#define NPCM_I2CFIF_CTS_RFTE_IE BIT(3)
#define NPCM_I2CFIF_CTS_CLR_FIFO BIT(6)
#define NPCM_I2CFIF_CTS_SLVRSTR BIT(7)
/* NPCM_I2CTXF_CTL reg field */
#define NPCM_I2CTXF_CTL_THR_TXIE BIT(6)
/* NPCM_I2CT_OUT reg fields */
#define NPCM_I2CT_OUT_TO_CKDIV GENMASK(5, 0)
#define NPCM_I2CT_OUT_T_OUTIE BIT(6)
#define NPCM_I2CT_OUT_T_OUTST BIT(7)
/* NPCM_I2CTXF_STS reg fields */
#define NPCM_I2CTXF_STS_TX_THST BIT(6)
/* NPCM_I2CRXF_STS reg fields */
#define NPCM_I2CRXF_STS_RX_THST BIT(6)
/* NPCM_I2CFIF_CTL reg fields */
#define NPCM_I2CFIF_CTL_FIFO_EN BIT(4)
/* NPCM_I2CRXF_CTL reg fields */
#define NPCM_I2CRXF_CTL_THR_RXIE BIT(6)
#define MAX_I2C_HW_FIFO_SIZE 32
/* I2C_VER reg fields */
#define I2C_VER_VERSION GENMASK(6, 0)
#define I2C_VER_FIFO_EN BIT(7)
/* stall/stuck timeout in us */
#define DEFAULT_STALL_COUNT 25
/* SCLFRQ field position */
#define SCLFRQ_0_TO_6 GENMASK(6, 0)
#define SCLFRQ_7_TO_8 GENMASK(8, 7)
/* supported clk settings. values in Hz. */
#define I2C_FREQ_MIN_HZ 10000
#define I2C_FREQ_MAX_HZ I2C_MAX_FAST_MODE_PLUS_FREQ
struct npcm_i2c_data {
u8 fifo_size;
u32 segctl_init_val;
u8 txf_sts_tx_bytes;
u8 rxf_sts_rx_bytes;
u8 rxf_ctl_last_pec;
};
static const struct npcm_i2c_data npxm7xx_i2c_data = {
.fifo_size = 16,
.segctl_init_val = 0x0333F000,
.txf_sts_tx_bytes = GENMASK(4, 0),
.rxf_sts_rx_bytes = GENMASK(4, 0),
.rxf_ctl_last_pec = BIT(5),
};
static const struct npcm_i2c_data npxm8xx_i2c_data = {
.fifo_size = 32,
.segctl_init_val = 0x9333F000,
.txf_sts_tx_bytes = GENMASK(5, 0),
.rxf_sts_rx_bytes = GENMASK(5, 0),
.rxf_ctl_last_pec = BIT(7),
};
/* Status of one I2C module */
struct npcm_i2c {
struct i2c_adapter adap;
struct device *dev;
unsigned char __iomem *reg;
const struct npcm_i2c_data *data;
spinlock_t lock; /* IRQ synchronization */
struct completion cmd_complete;
int cmd_err;
struct i2c_msg *msgs;
int msgs_num;
int num;
u32 apb_clk;
struct i2c_bus_recovery_info rinfo;
enum i2c_state state;
enum i2c_oper operation;
enum i2c_mode master_or_slave;
enum i2c_state_ind stop_ind;
u8 dest_addr;
u8 *rd_buf;
u16 rd_size;
u16 rd_ind;
u8 *wr_buf;
u16 wr_size;
u16 wr_ind;
bool fifo_use;
u16 PEC_mask; /* PEC bit mask per slave address */
bool PEC_use;
bool read_block_use;
unsigned long int_time_stamp;
unsigned long bus_freq; /* in Hz */
#if IS_ENABLED(CONFIG_I2C_SLAVE)
u8 own_slave_addr;
struct i2c_client *slave;
int slv_rd_size;
int slv_rd_ind;
int slv_wr_size;
int slv_wr_ind;
u8 slv_rd_buf[MAX_I2C_HW_FIFO_SIZE];
u8 slv_wr_buf[MAX_I2C_HW_FIFO_SIZE];
#endif
struct dentry *debugfs; /* debugfs device directory */
u64 ber_cnt;
u64 rec_succ_cnt;
u64 rec_fail_cnt;
u64 nack_cnt;
u64 timeout_cnt;
u64 tx_complete_cnt;
};
static inline void npcm_i2c_select_bank(struct npcm_i2c *bus,
enum i2c_bank bank)
{
u8 i2cctl3 = ioread8(bus->reg + NPCM_I2CCTL3);
if (bank == I2C_BANK_0)
i2cctl3 = i2cctl3 & ~I2CCTL3_BNK_SEL;
else
i2cctl3 = i2cctl3 | I2CCTL3_BNK_SEL;
iowrite8(i2cctl3, bus->reg + NPCM_I2CCTL3);
}
static void npcm_i2c_init_params(struct npcm_i2c *bus)
{
bus->stop_ind = I2C_NO_STATUS_IND;
bus->rd_size = 0;
bus->wr_size = 0;
bus->rd_ind = 0;
bus->wr_ind = 0;
bus->read_block_use = false;
bus->int_time_stamp = 0;
bus->PEC_use = false;
bus->PEC_mask = 0;
#if IS_ENABLED(CONFIG_I2C_SLAVE)
if (bus->slave)
bus->master_or_slave = I2C_SLAVE;
#endif
}
static inline void npcm_i2c_wr_byte(struct npcm_i2c *bus, u8 data)
{
iowrite8(data, bus->reg + NPCM_I2CSDA);
}
static inline u8 npcm_i2c_rd_byte(struct npcm_i2c *bus)
{
return ioread8(bus->reg + NPCM_I2CSDA);
}
static int npcm_i2c_get_SCL(struct i2c_adapter *_adap)
{
struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap);
return !!(I2CCTL3_SCL_LVL & ioread8(bus->reg + NPCM_I2CCTL3));
}
static int npcm_i2c_get_SDA(struct i2c_adapter *_adap)
{
struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap);
return !!(I2CCTL3_SDA_LVL & ioread8(bus->reg + NPCM_I2CCTL3));
}
static inline u16 npcm_i2c_get_index(struct npcm_i2c *bus)
{
if (bus->operation == I2C_READ_OPER)
return bus->rd_ind;
if (bus->operation == I2C_WRITE_OPER)
return bus->wr_ind;
return 0;
}
/* quick protocol (just address) */
static inline bool npcm_i2c_is_quick(struct npcm_i2c *bus)
{
return bus->wr_size == 0 && bus->rd_size == 0;
}
static void npcm_i2c_disable(struct npcm_i2c *bus)
{
u8 i2cctl2;
#if IS_ENABLED(CONFIG_I2C_SLAVE)
int i;
/* Slave addresses removal */
for (i = I2C_SLAVE_ADDR1; i < I2C_NUM_OWN_ADDR_SUPPORTED; i++)
iowrite8(0, bus->reg + npcm_i2caddr[i]);
#endif
/* Disable module */
i2cctl2 = ioread8(bus->reg + NPCM_I2CCTL2);
i2cctl2 = i2cctl2 & ~I2CCTL2_ENABLE;
iowrite8(i2cctl2, bus->reg + NPCM_I2CCTL2);
bus->state = I2C_DISABLE;
}
static void npcm_i2c_enable(struct npcm_i2c *bus)
{
u8 i2cctl2 = ioread8(bus->reg + NPCM_I2CCTL2);
i2cctl2 = i2cctl2 | I2CCTL2_ENABLE;
iowrite8(i2cctl2, bus->reg + NPCM_I2CCTL2);
bus->state = I2C_IDLE;
}
/* enable\disable end of busy (EOB) interrupts */
static inline void npcm_i2c_eob_int(struct npcm_i2c *bus, bool enable)
{
u8 val;
/* Clear EO_BUSY pending bit: */
val = ioread8(bus->reg + NPCM_I2CCST3);
val = val | NPCM_I2CCST3_EO_BUSY;
iowrite8(val, bus->reg + NPCM_I2CCST3);
val = ioread8(bus->reg + NPCM_I2CCTL1);
val &= ~NPCM_I2CCTL1_RWS;
if (enable)
val |= NPCM_I2CCTL1_EOBINTE;
else
val &= ~NPCM_I2CCTL1_EOBINTE;
iowrite8(val, bus->reg + NPCM_I2CCTL1);
}
static inline bool npcm_i2c_tx_fifo_empty(struct npcm_i2c *bus)
{
u8 tx_fifo_sts;
tx_fifo_sts = ioread8(bus->reg + NPCM_I2CTXF_STS);
/* check if TX FIFO is not empty */
if ((tx_fifo_sts & bus->data->txf_sts_tx_bytes) == 0)
return false;
/* check if TX FIFO status bit is set: */
return !!FIELD_GET(NPCM_I2CTXF_STS_TX_THST, tx_fifo_sts);
}
static inline bool npcm_i2c_rx_fifo_full(struct npcm_i2c *bus)
{
u8 rx_fifo_sts;
rx_fifo_sts = ioread8(bus->reg + NPCM_I2CRXF_STS);
/* check if RX FIFO is not empty: */
if ((rx_fifo_sts & bus->data->rxf_sts_rx_bytes) == 0)
return false;
/* check if rx fifo full status is set: */
return !!FIELD_GET(NPCM_I2CRXF_STS_RX_THST, rx_fifo_sts);
}
static inline void npcm_i2c_clear_fifo_int(struct npcm_i2c *bus)
{
u8 val;
val = ioread8(bus->reg + NPCM_I2CFIF_CTS);
val = (val & NPCM_I2CFIF_CTS_SLVRSTR) | NPCM_I2CFIF_CTS_RXF_TXE;
iowrite8(val, bus->reg + NPCM_I2CFIF_CTS);
}
static inline void npcm_i2c_clear_tx_fifo(struct npcm_i2c *bus)
{
u8 val;
val = ioread8(bus->reg + NPCM_I2CTXF_STS);
val = val | NPCM_I2CTXF_STS_TX_THST;
iowrite8(val, bus->reg + NPCM_I2CTXF_STS);
}
static inline void npcm_i2c_clear_rx_fifo(struct npcm_i2c *bus)
{
u8 val;
val = ioread8(bus->reg + NPCM_I2CRXF_STS);
val = val | NPCM_I2CRXF_STS_RX_THST;
iowrite8(val, bus->reg + NPCM_I2CRXF_STS);
}
static void npcm_i2c_int_enable(struct npcm_i2c *bus, bool enable)
{
u8 val;
val = ioread8(bus->reg + NPCM_I2CCTL1);
val &= ~NPCM_I2CCTL1_RWS;
if (enable)
val |= NPCM_I2CCTL1_INTEN;
else
val &= ~NPCM_I2CCTL1_INTEN;
iowrite8(val, bus->reg + NPCM_I2CCTL1);
}
static inline void npcm_i2c_master_start(struct npcm_i2c *bus)
{
u8 val;
val = ioread8(bus->reg + NPCM_I2CCTL1);
val &= ~(NPCM_I2CCTL1_STOP | NPCM_I2CCTL1_ACK);
val |= NPCM_I2CCTL1_START;
iowrite8(val, bus->reg + NPCM_I2CCTL1);
}
static inline void npcm_i2c_master_stop(struct npcm_i2c *bus)
{
u8 val;
/*
* override HW issue: I2C may fail to supply stop condition in Master
* Write operation.
* Need to delay at least 5 us from the last int, before issueing a stop
*/
udelay(10); /* function called from interrupt, can't sleep */
val = ioread8(bus->reg + NPCM_I2CCTL1);
val &= ~(NPCM_I2CCTL1_START | NPCM_I2CCTL1_ACK);
val |= NPCM_I2CCTL1_STOP;
iowrite8(val, bus->reg + NPCM_I2CCTL1);
if (!bus->fifo_use)
return;
npcm_i2c_select_bank(bus, I2C_BANK_1);
if (bus->operation == I2C_READ_OPER)
npcm_i2c_clear_rx_fifo(bus);
else
npcm_i2c_clear_tx_fifo(bus);
npcm_i2c_clear_fifo_int(bus);
iowrite8(0, bus->reg + NPCM_I2CTXF_CTL);
}
static inline void npcm_i2c_stall_after_start(struct npcm_i2c *bus, bool stall)
{
u8 val;
val = ioread8(bus->reg + NPCM_I2CCTL1);
val &= ~NPCM_I2CCTL1_RWS;
if (stall)
val |= NPCM_I2CCTL1_STASTRE;
else
val &= ~NPCM_I2CCTL1_STASTRE;
iowrite8(val, bus->reg + NPCM_I2CCTL1);
}
static inline void npcm_i2c_nack(struct npcm_i2c *bus)
{
u8 val;
val = ioread8(bus->reg + NPCM_I2CCTL1);
val &= ~(NPCM_I2CCTL1_STOP | NPCM_I2CCTL1_START);
val |= NPCM_I2CCTL1_ACK;
iowrite8(val, bus->reg + NPCM_I2CCTL1);
}
static inline void npcm_i2c_clear_master_status(struct npcm_i2c *bus)
{
u8 val;
/* Clear NEGACK, STASTR and BER bits */
val = NPCM_I2CST_BER | NPCM_I2CST_NEGACK | NPCM_I2CST_STASTR;
iowrite8(val, bus->reg + NPCM_I2CST);
}
#if IS_ENABLED(CONFIG_I2C_SLAVE)
static void npcm_i2c_slave_int_enable(struct npcm_i2c *bus, bool enable)
{
u8 i2cctl1;
/* enable interrupt on slave match: */
i2cctl1 = ioread8(bus->reg + NPCM_I2CCTL1);
i2cctl1 &= ~NPCM_I2CCTL1_RWS;
if (enable)
i2cctl1 |= NPCM_I2CCTL1_NMINTE;
else
i2cctl1 &= ~NPCM_I2CCTL1_NMINTE;
iowrite8(i2cctl1, bus->reg + NPCM_I2CCTL1);
}
static int npcm_i2c_slave_enable(struct npcm_i2c *bus, enum i2c_addr addr_type,
u8 addr, bool enable)
{
u8 i2cctl1;
u8 i2cctl3;
u8 sa_reg;
sa_reg = (addr & 0x7F) | FIELD_PREP(NPCM_I2CADDR_SAEN, enable);
if (addr_type == I2C_GC_ADDR) {
i2cctl1 = ioread8(bus->reg + NPCM_I2CCTL1);
if (enable)
i2cctl1 |= NPCM_I2CCTL1_GCMEN;
else
i2cctl1 &= ~NPCM_I2CCTL1_GCMEN;
iowrite8(i2cctl1, bus->reg + NPCM_I2CCTL1);
return 0;
} else if (addr_type == I2C_ARP_ADDR) {
i2cctl3 = ioread8(bus->reg + NPCM_I2CCTL3);
if (enable)
i2cctl3 |= I2CCTL3_ARPMEN;
else
i2cctl3 &= ~I2CCTL3_ARPMEN;
iowrite8(i2cctl3, bus->reg + NPCM_I2CCTL3);
return 0;
}
if (addr_type > I2C_SLAVE_ADDR2 && addr_type <= I2C_SLAVE_ADDR10)
dev_err(bus->dev, "try to enable more than 2 SA not supported\n");
if (addr_type >= I2C_ARP_ADDR)
return -EFAULT;
/* Set and enable the address */
iowrite8(sa_reg, bus->reg + npcm_i2caddr[addr_type]);
npcm_i2c_slave_int_enable(bus, enable);
return 0;
}
#endif
static void npcm_i2c_reset(struct npcm_i2c *bus)
{
/*
* Save I2CCTL1 relevant bits. It is being cleared when the module
* is disabled.
*/
u8 i2cctl1;
#if IS_ENABLED(CONFIG_I2C_SLAVE)
u8 addr;
#endif
i2cctl1 = ioread8(bus->reg + NPCM_I2CCTL1);
npcm_i2c_disable(bus);
npcm_i2c_enable(bus);
/* Restore NPCM_I2CCTL1 Status */
i2cctl1 &= ~NPCM_I2CCTL1_RWS;
iowrite8(i2cctl1, bus->reg + NPCM_I2CCTL1);
/* Clear BB (BUS BUSY) bit */
iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
iowrite8(0xFF, bus->reg + NPCM_I2CST);
/* Clear and disable EOB */
npcm_i2c_eob_int(bus, false);
/* Clear all fifo bits: */
iowrite8(NPCM_I2CFIF_CTS_CLR_FIFO, bus->reg + NPCM_I2CFIF_CTS);
#if IS_ENABLED(CONFIG_I2C_SLAVE)
if (bus->slave) {
addr = bus->slave->addr;
npcm_i2c_slave_enable(bus, I2C_SLAVE_ADDR1, addr, true);
}
#endif
/* Clear status bits for spurious interrupts */
npcm_i2c_clear_master_status(bus);
bus->state = I2C_IDLE;
}
static inline bool npcm_i2c_is_master(struct npcm_i2c *bus)
{
return !!FIELD_GET(NPCM_I2CST_MASTER, ioread8(bus->reg + NPCM_I2CST));
}
static void npcm_i2c_callback(struct npcm_i2c *bus,
enum i2c_state_ind op_status, u16 info)
{
struct i2c_msg *msgs;
int msgs_num;
msgs = bus->msgs;
msgs_num = bus->msgs_num;
/*
* check that transaction was not timed-out, and msgs still
* holds a valid value.
*/
if (!msgs)
return;
if (completion_done(&bus->cmd_complete))
return;
switch (op_status) {
case I2C_MASTER_DONE_IND:
bus->cmd_err = bus->msgs_num;
if (bus->tx_complete_cnt < ULLONG_MAX)
bus->tx_complete_cnt++;
fallthrough;
case I2C_BLOCK_BYTES_ERR_IND:
/* Master tx finished and all transmit bytes were sent */
if (bus->msgs) {
if (msgs[0].flags & I2C_M_RD)
msgs[0].len = info;
else if (msgs_num == 2 &&
msgs[1].flags & I2C_M_RD)
msgs[1].len = info;
}
if (completion_done(&bus->cmd_complete) == false)
complete(&bus->cmd_complete);
break;
case I2C_NACK_IND:
/* MASTER transmit got a NACK before tx all bytes */
bus->cmd_err = -ENXIO;
if (bus->master_or_slave == I2C_MASTER)
complete(&bus->cmd_complete);
break;
case I2C_BUS_ERR_IND:
/* Bus error */
bus->cmd_err = -EAGAIN;
if (bus->master_or_slave == I2C_MASTER)
complete(&bus->cmd_complete);
break;
case I2C_WAKE_UP_IND:
/* I2C wake up */
break;
default:
break;
}
bus->operation = I2C_NO_OPER;
#if IS_ENABLED(CONFIG_I2C_SLAVE)
if (bus->slave)
bus->master_or_slave = I2C_SLAVE;
#endif
}
static u8 npcm_i2c_fifo_usage(struct npcm_i2c *bus)
{
if (bus->operation == I2C_WRITE_OPER)
return (bus->data->txf_sts_tx_bytes &
ioread8(bus->reg + NPCM_I2CTXF_STS));
if (bus->operation == I2C_READ_OPER)
return (bus->data->rxf_sts_rx_bytes &
ioread8(bus->reg + NPCM_I2CRXF_STS));
return 0;
}
static void npcm_i2c_write_to_fifo_master(struct npcm_i2c *bus, u16 max_bytes)
{
u8 size_free_fifo;
/*
* Fill the FIFO, while the FIFO is not full and there are more bytes
* to write
*/
size_free_fifo = bus->data->fifo_size - npcm_i2c_fifo_usage(bus);
while (max_bytes-- && size_free_fifo) {
if (bus->wr_ind < bus->wr_size)
npcm_i2c_wr_byte(bus, bus->wr_buf[bus->wr_ind++]);
else
npcm_i2c_wr_byte(bus, 0xFF);
size_free_fifo = bus->data->fifo_size - npcm_i2c_fifo_usage(bus);
}
}
/*
* npcm_i2c_set_fifo:
* configure the FIFO before using it. If nread is -1 RX FIFO will not be
* configured. same for nwrite
*/
static void npcm_i2c_set_fifo(struct npcm_i2c *bus, int nread, int nwrite)
{
u8 rxf_ctl = 0;
if (!bus->fifo_use)
return;
npcm_i2c_select_bank(bus, I2C_BANK_1);
npcm_i2c_clear_tx_fifo(bus);
npcm_i2c_clear_rx_fifo(bus);
/* configure RX FIFO */
if (nread > 0) {
rxf_ctl = min_t(int, nread, bus->data->fifo_size);
/* set LAST bit. if LAST is set next FIFO packet is nacked */
if (nread <= bus->data->fifo_size)
rxf_ctl |= bus->data->rxf_ctl_last_pec;
/*
* if we are about to read the first byte in blk rd mode,
* don't NACK it. If slave returns zero size HW can't NACK
* it immediately, it will read extra byte and then NACK.
*/
if (bus->rd_ind == 0 && bus->read_block_use) {
/* set fifo to read one byte, no last: */
rxf_ctl = 1;
}
/* set fifo size: */
iowrite8(rxf_ctl, bus->reg + NPCM_I2CRXF_CTL);
}
/* configure TX FIFO */
if (nwrite > 0) {
if (nwrite > bus->data->fifo_size)
/* data to send is more then FIFO size. */
iowrite8(bus->data->fifo_size, bus->reg + NPCM_I2CTXF_CTL);
else
iowrite8(nwrite, bus->reg + NPCM_I2CTXF_CTL);
npcm_i2c_clear_tx_fifo(bus);
}
}
static void npcm_i2c_read_fifo(struct npcm_i2c *bus, u8 bytes_in_fifo)
{
u8 data;
while (bytes_in_fifo--) {
data = npcm_i2c_rd_byte(bus);
if (bus->rd_ind < bus->rd_size)
bus->rd_buf[bus->rd_ind++] = data;
}
}
static void npcm_i2c_master_abort(struct npcm_i2c *bus)
{
/* Only current master is allowed to issue a stop condition */
if (!npcm_i2c_is_master(bus))
return;
npcm_i2c_eob_int(bus, true);
npcm_i2c_master_stop(bus);
npcm_i2c_clear_master_status(bus);
}
#if IS_ENABLED(CONFIG_I2C_SLAVE)
static u8 npcm_i2c_get_slave_addr(struct npcm_i2c *bus, enum i2c_addr addr_type)
{
u8 slave_add;
if (addr_type > I2C_SLAVE_ADDR2 && addr_type <= I2C_SLAVE_ADDR10)
dev_err(bus->dev, "get slave: try to use more than 2 SA not supported\n");
slave_add = ioread8(bus->reg + npcm_i2caddr[(int)addr_type]);
return slave_add;
}
static int npcm_i2c_remove_slave_addr(struct npcm_i2c *bus, u8 slave_add)
{
int i;
/* Set the enable bit */
slave_add |= 0x80;
for (i = I2C_SLAVE_ADDR1; i < I2C_NUM_OWN_ADDR_SUPPORTED; i++) {
if (ioread8(bus->reg + npcm_i2caddr[i]) == slave_add)
iowrite8(0, bus->reg + npcm_i2caddr[i]);
}
return 0;
}
static void npcm_i2c_write_fifo_slave(struct npcm_i2c *bus, u16 max_bytes)
{
/*
* Fill the FIFO, while the FIFO is not full and there are more bytes
* to write
*/
npcm_i2c_clear_fifo_int(bus);
npcm_i2c_clear_tx_fifo(bus);
iowrite8(0, bus->reg + NPCM_I2CTXF_CTL);
while (max_bytes-- && bus->data->fifo_size != npcm_i2c_fifo_usage(bus)) {
if (bus->slv_wr_size <= 0)
break;
bus->slv_wr_ind = bus->slv_wr_ind & (bus->data->fifo_size - 1);
npcm_i2c_wr_byte(bus, bus->slv_wr_buf[bus->slv_wr_ind]);
bus->slv_wr_ind++;
bus->slv_wr_ind = bus->slv_wr_ind & (bus->data->fifo_size - 1);
bus->slv_wr_size--;
}
}
static void npcm_i2c_read_fifo_slave(struct npcm_i2c *bus, u8 bytes_in_fifo)
{
u8 data;
if (!bus->slave)
return;
while (bytes_in_fifo--) {
data = npcm_i2c_rd_byte(bus);
bus->slv_rd_ind = bus->slv_rd_ind & (bus->data->fifo_size - 1);
bus->slv_rd_buf[bus->slv_rd_ind] = data;
bus->slv_rd_ind++;
/* 1st byte is length in block protocol: */
if (bus->slv_rd_ind == 1 && bus->read_block_use)
bus->slv_rd_size = data + bus->PEC_use + 1;
}
}
static int npcm_i2c_slave_get_wr_buf(struct npcm_i2c *bus)
{
int i;
u8 value;
int ind;
int ret = bus->slv_wr_ind;
/* fill a cyclic buffer */
for (i = 0; i < bus->data->fifo_size; i++) {
if (bus->slv_wr_size >= bus->data->fifo_size)
break;
if (bus->state == I2C_SLAVE_MATCH) {
i2c_slave_event(bus->slave, I2C_SLAVE_READ_REQUESTED, &value);
bus->state = I2C_OPER_STARTED;
} else {
i2c_slave_event(bus->slave, I2C_SLAVE_READ_PROCESSED, &value);
}
ind = (bus->slv_wr_ind + bus->slv_wr_size) & (bus->data->fifo_size - 1);
bus->slv_wr_buf[ind] = value;
bus->slv_wr_size++;
}
return bus->data->fifo_size - ret;
}
static void npcm_i2c_slave_send_rd_buf(struct npcm_i2c *bus)
{
int i;
for (i = 0; i < bus->slv_rd_ind; i++)
i2c_slave_event(bus->slave, I2C_SLAVE_WRITE_RECEIVED,
&bus->slv_rd_buf[i]);
/*
* once we send bytes up, need to reset the counter of the wr buf
* got data from master (new offset in device), ignore wr fifo:
*/
if (bus->slv_rd_ind) {
bus->slv_wr_size = 0;
bus->slv_wr_ind = 0;
}
bus->slv_rd_ind = 0;
bus->slv_rd_size = bus->adap.quirks->max_read_len;
npcm_i2c_clear_fifo_int(bus);
npcm_i2c_clear_rx_fifo(bus);
}
static void npcm_i2c_slave_receive(struct npcm_i2c *bus, u16 nread,
u8 *read_data)
{
bus->state = I2C_OPER_STARTED;
bus->operation = I2C_READ_OPER;
bus->slv_rd_size = nread;
bus->slv_rd_ind = 0;
iowrite8(0, bus->reg + NPCM_I2CTXF_CTL);
iowrite8(bus->data->fifo_size, bus->reg + NPCM_I2CRXF_CTL);
npcm_i2c_clear_tx_fifo(bus);
npcm_i2c_clear_rx_fifo(bus);
}
static void npcm_i2c_slave_xmit(struct npcm_i2c *bus, u16 nwrite,
u8 *write_data)
{
if (nwrite == 0)
return;
bus->operation = I2C_WRITE_OPER;
/* get the next buffer */
npcm_i2c_slave_get_wr_buf(bus);
npcm_i2c_write_fifo_slave(bus, nwrite);
}
/*
* npcm_i2c_slave_wr_buf_sync:
* currently slave IF only supports single byte operations.
* in order to utilize the npcm HW FIFO, the driver will ask for 16 bytes
* at a time, pack them in buffer, and then transmit them all together
* to the FIFO and onward to the bus.
* NACK on read will be once reached to bus->adap->quirks->max_read_len.
* sending a NACK wherever the backend requests for it is not supported.
* the next two functions allow reading to local buffer before writing it all
* to the HW FIFO.
*/
static void npcm_i2c_slave_wr_buf_sync(struct npcm_i2c *bus)
{
int left_in_fifo;
left_in_fifo = bus->data->txf_sts_tx_bytes &
ioread8(bus->reg + NPCM_I2CTXF_STS);
/* fifo already full: */
if (left_in_fifo >= bus->data->fifo_size ||
bus->slv_wr_size >= bus->data->fifo_size)
return;
/* update the wr fifo index back to the untransmitted bytes: */
bus->slv_wr_ind = bus->slv_wr_ind - left_in_fifo;
bus->slv_wr_size = bus->slv_wr_size + left_in_fifo;
if (bus->slv_wr_ind < 0)
bus->slv_wr_ind += bus->data->fifo_size;
}
static void npcm_i2c_slave_rd_wr(struct npcm_i2c *bus)
{
if (NPCM_I2CST_XMIT & ioread8(bus->reg + NPCM_I2CST)) {
/*
* Slave got an address match with direction bit 1 so it should
* transmit data. Write till the master will NACK
*/
bus->operation = I2C_WRITE_OPER;
npcm_i2c_slave_xmit(bus, bus->adap.quirks->max_write_len,
bus->slv_wr_buf);
} else {
/*
* Slave got an address match with direction bit 0 so it should
* receive data.
* this module does not support saying no to bytes.
* it will always ACK.
*/
bus->operation = I2C_READ_OPER;
npcm_i2c_read_fifo_slave(bus, npcm_i2c_fifo_usage(bus));
bus->stop_ind = I2C_SLAVE_RCV_IND;
npcm_i2c_slave_send_rd_buf(bus);
npcm_i2c_slave_receive(bus, bus->adap.quirks->max_read_len,
bus->slv_rd_buf);
}
}
static irqreturn_t npcm_i2c_int_slave_handler(struct npcm_i2c *bus)
{
u8 val;
irqreturn_t ret = IRQ_NONE;
u8 i2cst = ioread8(bus->reg + NPCM_I2CST);
/* Slave: A NACK has occurred */
if (NPCM_I2CST_NEGACK & i2cst) {
bus->stop_ind = I2C_NACK_IND;
npcm_i2c_slave_wr_buf_sync(bus);
if (bus->fifo_use)
/* clear the FIFO */
iowrite8(NPCM_I2CFIF_CTS_CLR_FIFO,
bus->reg + NPCM_I2CFIF_CTS);
/* In slave write, NACK is OK, otherwise it is a problem */
bus->stop_ind = I2C_NO_STATUS_IND;
bus->operation = I2C_NO_OPER;
bus->own_slave_addr = 0xFF;
/*
* Slave has to wait for STOP to decide this is the end
* of the transaction. tx is not yet considered as done
*/
iowrite8(NPCM_I2CST_NEGACK, bus->reg + NPCM_I2CST);
ret = IRQ_HANDLED;
}
/* Slave mode: a Bus Error (BER) has been identified */
if (NPCM_I2CST_BER & i2cst) {
/*
* Check whether bus arbitration or Start or Stop during data
* xfer bus arbitration problem should not result in recovery
*/
bus->stop_ind = I2C_BUS_ERR_IND;
/* wait for bus busy before clear fifo */
iowrite8(NPCM_I2CFIF_CTS_CLR_FIFO, bus->reg + NPCM_I2CFIF_CTS);
bus->state = I2C_IDLE;
/*
* in BER case we might get 2 interrupts: one for slave one for
* master ( for a channel which is master\slave switching)
*/
if (completion_done(&bus->cmd_complete) == false) {
bus->cmd_err = -EIO;
complete(&bus->cmd_complete);
}
bus->own_slave_addr = 0xFF;
iowrite8(NPCM_I2CST_BER, bus->reg + NPCM_I2CST);
ret = IRQ_HANDLED;
}
/* A Slave Stop Condition has been identified */
if (NPCM_I2CST_SLVSTP & i2cst) {
u8 bytes_in_fifo = npcm_i2c_fifo_usage(bus);
bus->stop_ind = I2C_SLAVE_DONE_IND;
if (bus->operation == I2C_READ_OPER)
npcm_i2c_read_fifo_slave(bus, bytes_in_fifo);
/* if the buffer is empty nothing will be sent */
npcm_i2c_slave_send_rd_buf(bus);
/* Slave done transmitting or receiving */
bus->stop_ind = I2C_NO_STATUS_IND;
/*
* Note, just because we got here, it doesn't mean we through
* away the wr buffer.
* we keep it until the next received offset.
*/
bus->operation = I2C_NO_OPER;
bus->own_slave_addr = 0xFF;
i2c_slave_event(bus->slave, I2C_SLAVE_STOP, 0);
iowrite8(NPCM_I2CST_SLVSTP, bus->reg + NPCM_I2CST);
if (bus->fifo_use) {
npcm_i2c_clear_fifo_int(bus);
npcm_i2c_clear_rx_fifo(bus);
npcm_i2c_clear_tx_fifo(bus);
iowrite8(NPCM_I2CFIF_CTS_CLR_FIFO,
bus->reg + NPCM_I2CFIF_CTS);
}
bus->state = I2C_IDLE;
ret = IRQ_HANDLED;
}
/* restart condition occurred and Rx-FIFO was not empty */
if (bus->fifo_use && FIELD_GET(NPCM_I2CFIF_CTS_SLVRSTR,
ioread8(bus->reg + NPCM_I2CFIF_CTS))) {
bus->stop_ind = I2C_SLAVE_RESTART_IND;
bus->master_or_slave = I2C_SLAVE;
if (bus->operation == I2C_READ_OPER)
npcm_i2c_read_fifo_slave(bus, npcm_i2c_fifo_usage(bus));
bus->operation = I2C_WRITE_OPER;
iowrite8(0, bus->reg + NPCM_I2CRXF_CTL);
val = NPCM_I2CFIF_CTS_CLR_FIFO | NPCM_I2CFIF_CTS_SLVRSTR |
NPCM_I2CFIF_CTS_RXF_TXE;
iowrite8(val, bus->reg + NPCM_I2CFIF_CTS);
npcm_i2c_slave_rd_wr(bus);
ret = IRQ_HANDLED;
}
/* A Slave Address Match has been identified */
if (NPCM_I2CST_NMATCH & i2cst) {
u8 info = 0;
/* Address match automatically implies slave mode */
bus->master_or_slave = I2C_SLAVE;
npcm_i2c_clear_fifo_int(bus);
npcm_i2c_clear_rx_fifo(bus);
npcm_i2c_clear_tx_fifo(bus);
iowrite8(0, bus->reg + NPCM_I2CTXF_CTL);
iowrite8(bus->data->fifo_size, bus->reg + NPCM_I2CRXF_CTL);
if (NPCM_I2CST_XMIT & i2cst) {
bus->operation = I2C_WRITE_OPER;
} else {
i2c_slave_event(bus->slave, I2C_SLAVE_WRITE_REQUESTED,
&info);
bus->operation = I2C_READ_OPER;
}
if (bus->own_slave_addr == 0xFF) {
/* Check which type of address match */
val = ioread8(bus->reg + NPCM_I2CCST);
if (NPCM_I2CCST_MATCH & val) {
u16 addr;
enum i2c_addr eaddr;
u8 i2ccst2;
u8 i2ccst3;
i2ccst3 = ioread8(bus->reg + NPCM_I2CCST3);
i2ccst2 = ioread8(bus->reg + NPCM_I2CCST2);
/*
* the i2c module can response to 10 own SA.
* check which one was addressed by the master.
* respond to the first one.
*/
addr = ((i2ccst3 & 0x07) << 7) |
(i2ccst2 & 0x7F);
info = ffs(addr);
eaddr = (enum i2c_addr)info;
addr = npcm_i2c_get_slave_addr(bus, eaddr);
addr &= 0x7F;
bus->own_slave_addr = addr;
if (bus->PEC_mask & BIT(info))
bus->PEC_use = true;
else
bus->PEC_use = false;
} else {
if (NPCM_I2CCST_GCMATCH & val)
bus->own_slave_addr = 0;
if (NPCM_I2CCST_ARPMATCH & val)
bus->own_slave_addr = 0x61;
}
} else {
/*
* Slave match can happen in two options:
* 1. Start, SA, read (slave read without further ado)
* 2. Start, SA, read, data, restart, SA, read, ...
* (slave read in fragmented mode)
* 3. Start, SA, write, data, restart, SA, read, ..
* (regular write-read mode)
*/
if ((bus->state == I2C_OPER_STARTED &&
bus->operation == I2C_READ_OPER &&
bus->stop_ind == I2C_SLAVE_XMIT_IND) ||
bus->stop_ind == I2C_SLAVE_RCV_IND) {
/* slave tx after slave rx w/o STOP */
bus->stop_ind = I2C_SLAVE_RESTART_IND;
}
}
if (NPCM_I2CST_XMIT & i2cst)
bus->stop_ind = I2C_SLAVE_XMIT_IND;
else
bus->stop_ind = I2C_SLAVE_RCV_IND;
bus->state = I2C_SLAVE_MATCH;
npcm_i2c_slave_rd_wr(bus);
iowrite8(NPCM_I2CST_NMATCH, bus->reg + NPCM_I2CST);
ret = IRQ_HANDLED;
}
/* Slave SDA status is set - tx or rx */
if ((NPCM_I2CST_SDAST & i2cst) ||
(bus->fifo_use &&
(npcm_i2c_tx_fifo_empty(bus) || npcm_i2c_rx_fifo_full(bus)))) {
npcm_i2c_slave_rd_wr(bus);
iowrite8(NPCM_I2CST_SDAST, bus->reg + NPCM_I2CST);
ret = IRQ_HANDLED;
} /* SDAST */
/*
* If irq is not one of the above, make sure EOB is disabled and all
* status bits are cleared.
*/
if (ret == IRQ_NONE) {
npcm_i2c_eob_int(bus, false);
npcm_i2c_clear_master_status(bus);
}
return IRQ_HANDLED;
}
static int npcm_i2c_reg_slave(struct i2c_client *client)
{
unsigned long lock_flags;
struct npcm_i2c *bus = i2c_get_adapdata(client->adapter);
bus->slave = client;
if (!bus->slave)
return -EINVAL;
if (client->flags & I2C_CLIENT_TEN)
return -EAFNOSUPPORT;
spin_lock_irqsave(&bus->lock, lock_flags);
npcm_i2c_init_params(bus);
bus->slv_rd_size = 0;
bus->slv_wr_size = 0;
bus->slv_rd_ind = 0;
bus->slv_wr_ind = 0;
if (client->flags & I2C_CLIENT_PEC)
bus->PEC_use = true;
dev_info(bus->dev, "i2c%d register slave SA=0x%x, PEC=%d\n", bus->num,
client->addr, bus->PEC_use);
npcm_i2c_slave_enable(bus, I2C_SLAVE_ADDR1, client->addr, true);
npcm_i2c_clear_fifo_int(bus);
npcm_i2c_clear_rx_fifo(bus);
npcm_i2c_clear_tx_fifo(bus);
npcm_i2c_slave_int_enable(bus, true);
spin_unlock_irqrestore(&bus->lock, lock_flags);
return 0;
}
static int npcm_i2c_unreg_slave(struct i2c_client *client)
{
struct npcm_i2c *bus = client->adapter->algo_data;
unsigned long lock_flags;
spin_lock_irqsave(&bus->lock, lock_flags);
if (!bus->slave) {
spin_unlock_irqrestore(&bus->lock, lock_flags);
return -EINVAL;
}
npcm_i2c_slave_int_enable(bus, false);
npcm_i2c_remove_slave_addr(bus, client->addr);
bus->slave = NULL;
spin_unlock_irqrestore(&bus->lock, lock_flags);
return 0;
}
#endif /* CONFIG_I2C_SLAVE */
static void npcm_i2c_master_fifo_read(struct npcm_i2c *bus)
{
int rcount;
int fifo_bytes;
enum i2c_state_ind ind = I2C_MASTER_DONE_IND;
fifo_bytes = npcm_i2c_fifo_usage(bus);
rcount = bus->rd_size - bus->rd_ind;
/*
* In order not to change the RX_TRH during transaction (we found that
* this might be problematic if it takes too much time to read the FIFO)
* we read the data in the following way. If the number of bytes to
* read == FIFO Size + C (where C < FIFO Size)then first read C bytes
* and in the next int we read rest of the data.
*/
if (rcount < (2 * bus->data->fifo_size) && rcount > bus->data->fifo_size)
fifo_bytes = rcount - bus->data->fifo_size;
if (rcount <= fifo_bytes) {
/* last bytes are about to be read - end of tx */
bus->state = I2C_STOP_PENDING;
bus->stop_ind = ind;
npcm_i2c_eob_int(bus, true);
/* Stop should be set before reading last byte. */
npcm_i2c_master_stop(bus);
npcm_i2c_read_fifo(bus, fifo_bytes);
} else {
npcm_i2c_read_fifo(bus, fifo_bytes);
rcount = bus->rd_size - bus->rd_ind;
npcm_i2c_set_fifo(bus, rcount, -1);
}
}
static void npcm_i2c_irq_master_handler_write(struct npcm_i2c *bus)
{
u16 wcount;
if (bus->fifo_use)
npcm_i2c_clear_tx_fifo(bus); /* clear the TX fifo status bit */
/* Master write operation - last byte handling */
if (bus->wr_ind == bus->wr_size) {
if (bus->fifo_use && npcm_i2c_fifo_usage(bus) > 0)
/*
* No more bytes to send (to add to the FIFO),
* however the FIFO is not empty yet. It is
* still in the middle of tx. Currently there's nothing
* to do except for waiting to the end of the tx
* We will get an int when the FIFO will get empty.
*/
return;
if (bus->rd_size == 0) {
/* all bytes have been written, in wr only operation */
npcm_i2c_eob_int(bus, true);
bus->state = I2C_STOP_PENDING;
bus->stop_ind = I2C_MASTER_DONE_IND;
npcm_i2c_master_stop(bus);
/* Clear SDA Status bit (by writing dummy byte) */
npcm_i2c_wr_byte(bus, 0xFF);
} else {
/* last write-byte written on previous int - restart */
npcm_i2c_set_fifo(bus, bus->rd_size, -1);
/* Generate repeated start upon next write to SDA */
npcm_i2c_master_start(bus);
/*
* Receiving one byte only - stall after successful
* completion of send address byte. If we NACK here, and
* slave doesn't ACK the address, we might
* unintentionally NACK the next multi-byte read.
*/
if (bus->rd_size == 1)
npcm_i2c_stall_after_start(bus, true);
/* Next int will occur on read */
bus->operation = I2C_READ_OPER;
/* send the slave address in read direction */
npcm_i2c_wr_byte(bus, bus->dest_addr | 0x1);
}
} else {
/* write next byte not last byte and not slave address */
if (!bus->fifo_use || bus->wr_size == 1) {
npcm_i2c_wr_byte(bus, bus->wr_buf[bus->wr_ind++]);
} else {
wcount = bus->wr_size - bus->wr_ind;
npcm_i2c_set_fifo(bus, -1, wcount);
if (wcount)
npcm_i2c_write_to_fifo_master(bus, wcount);
}
}
}
static void npcm_i2c_irq_master_handler_read(struct npcm_i2c *bus)
{
u16 block_extra_bytes_size;
u8 data;
/* added bytes to the packet: */
block_extra_bytes_size = bus->read_block_use + bus->PEC_use;
/*
* Perform master read, distinguishing between last byte and the rest of
* the bytes. The last byte should be read when the clock is stopped
*/
if (bus->rd_ind == 0) { /* first byte handling: */
if (bus->read_block_use) {
/* first byte in block protocol is the size: */
data = npcm_i2c_rd_byte(bus);
data = clamp_val(data, 1, I2C_SMBUS_BLOCK_MAX);
bus->rd_size = data + block_extra_bytes_size;
bus->rd_buf[bus->rd_ind++] = data;
/* clear RX FIFO interrupt status: */
if (bus->fifo_use) {
data = ioread8(bus->reg + NPCM_I2CFIF_CTS);
data = data | NPCM_I2CFIF_CTS_RXF_TXE;
iowrite8(data, bus->reg + NPCM_I2CFIF_CTS);
}
npcm_i2c_set_fifo(bus, bus->rd_size - 1, -1);
npcm_i2c_stall_after_start(bus, false);
} else {
npcm_i2c_clear_tx_fifo(bus);
npcm_i2c_master_fifo_read(bus);
}
} else {
if (bus->rd_size == block_extra_bytes_size &&
bus->read_block_use) {
bus->state = I2C_STOP_PENDING;
bus->stop_ind = I2C_BLOCK_BYTES_ERR_IND;
bus->cmd_err = -EIO;
npcm_i2c_eob_int(bus, true);
npcm_i2c_master_stop(bus);
npcm_i2c_read_fifo(bus, npcm_i2c_fifo_usage(bus));
} else {
npcm_i2c_master_fifo_read(bus);
}
}
}
static void npcm_i2c_irq_handle_nmatch(struct npcm_i2c *bus)
{
iowrite8(NPCM_I2CST_NMATCH, bus->reg + NPCM_I2CST);
npcm_i2c_nack(bus);
bus->stop_ind = I2C_BUS_ERR_IND;
npcm_i2c_callback(bus, bus->stop_ind, npcm_i2c_get_index(bus));
}
/* A NACK has occurred */
static void npcm_i2c_irq_handle_nack(struct npcm_i2c *bus)
{
u8 val;
if (bus->nack_cnt < ULLONG_MAX)
bus->nack_cnt++;
if (bus->fifo_use) {
/*
* if there are still untransmitted bytes in TX FIFO
* reduce them from wr_ind
*/
if (bus->operation == I2C_WRITE_OPER)
bus->wr_ind -= npcm_i2c_fifo_usage(bus);
/* clear the FIFO */
iowrite8(NPCM_I2CFIF_CTS_CLR_FIFO, bus->reg + NPCM_I2CFIF_CTS);
}
/* In master write operation, got unexpected NACK */
bus->stop_ind = I2C_NACK_IND;
/* Only current master is allowed to issue Stop Condition */
if (npcm_i2c_is_master(bus)) {
/* stopping in the middle */
npcm_i2c_eob_int(bus, false);
npcm_i2c_master_stop(bus);
/* Clear SDA Status bit (by reading dummy byte) */
npcm_i2c_rd_byte(bus);
/*
* The bus is released from stall only after the SW clears
* NEGACK bit. Then a Stop condition is sent.
*/
npcm_i2c_clear_master_status(bus);
readx_poll_timeout_atomic(ioread8, bus->reg + NPCM_I2CCST, val,
!(val & NPCM_I2CCST_BUSY), 10, 200);
/* Verify no status bits are still set after bus is released */
npcm_i2c_clear_master_status(bus);
}
bus->state = I2C_IDLE;
/*
* In Master mode, NACK should be cleared only after STOP.
* In such case, the bus is released from stall only after the
* software clears NACK bit. Then a Stop condition is sent.
*/
npcm_i2c_callback(bus, bus->stop_ind, bus->wr_ind);
}
/* Master mode: a Bus Error has been identified */
static void npcm_i2c_irq_handle_ber(struct npcm_i2c *bus)
{
if (bus->ber_cnt < ULLONG_MAX)
bus->ber_cnt++;
bus->stop_ind = I2C_BUS_ERR_IND;
if (npcm_i2c_is_master(bus)) {
npcm_i2c_master_abort(bus);
} else {
npcm_i2c_clear_master_status(bus);
/* Clear BB (BUS BUSY) bit */
iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
bus->cmd_err = -EAGAIN;
npcm_i2c_callback(bus, bus->stop_ind, npcm_i2c_get_index(bus));
}
bus->state = I2C_IDLE;
}
/* EOB: a master End Of Busy (meaning STOP completed) */
static void npcm_i2c_irq_handle_eob(struct npcm_i2c *bus)
{
npcm_i2c_eob_int(bus, false);
bus->state = I2C_IDLE;
npcm_i2c_callback(bus, bus->stop_ind, bus->rd_ind);
}
/* Address sent and requested stall occurred (Master mode) */
static void npcm_i2c_irq_handle_stall_after_start(struct npcm_i2c *bus)
{
if (npcm_i2c_is_quick(bus)) {
bus->state = I2C_STOP_PENDING;
bus->stop_ind = I2C_MASTER_DONE_IND;
npcm_i2c_eob_int(bus, true);
npcm_i2c_master_stop(bus);
} else if ((bus->rd_size == 1) && !bus->read_block_use) {
/*
* Receiving one byte only - set NACK after ensuring
* slave ACKed the address byte.
*/
npcm_i2c_nack(bus);
}
/* Reset stall-after-address-byte */
npcm_i2c_stall_after_start(bus, false);
/* Clear stall only after setting STOP */
iowrite8(NPCM_I2CST_STASTR, bus->reg + NPCM_I2CST);
}
/* SDA status is set - TX or RX, master */
static void npcm_i2c_irq_handle_sda(struct npcm_i2c *bus, u8 i2cst)
{
u8 fif_cts;
if (!npcm_i2c_is_master(bus))
return;
if (bus->state == I2C_IDLE) {
bus->stop_ind = I2C_WAKE_UP_IND;
if (npcm_i2c_is_quick(bus) || bus->read_block_use)
/*
* Need to stall after successful
* completion of sending address byte
*/
npcm_i2c_stall_after_start(bus, true);
else
npcm_i2c_stall_after_start(bus, false);
/*
* Receiving one byte only - stall after successful completion
* of sending address byte If we NACK here, and slave doesn't
* ACK the address, we might unintentionally NACK the next
* multi-byte read
*/
if (bus->wr_size == 0 && bus->rd_size == 1)
npcm_i2c_stall_after_start(bus, true);
/* Initiate I2C master tx */
/* select bank 1 for FIFO regs */
npcm_i2c_select_bank(bus, I2C_BANK_1);
fif_cts = ioread8(bus->reg + NPCM_I2CFIF_CTS);
fif_cts = fif_cts & ~NPCM_I2CFIF_CTS_SLVRSTR;
/* clear FIFO and relevant status bits. */
fif_cts = fif_cts | NPCM_I2CFIF_CTS_CLR_FIFO;
iowrite8(fif_cts, bus->reg + NPCM_I2CFIF_CTS);
/* re-enable */
fif_cts = fif_cts | NPCM_I2CFIF_CTS_RXF_TXE;
iowrite8(fif_cts, bus->reg + NPCM_I2CFIF_CTS);
/*
* Configure the FIFO threshold:
* according to the needed # of bytes to read.
* Note: due to HW limitation can't config the rx fifo before it
* got and ACK on the restart. LAST bit will not be reset unless
* RX completed. It will stay set on the next tx.
*/
if (bus->wr_size)
npcm_i2c_set_fifo(bus, -1, bus->wr_size);
else
npcm_i2c_set_fifo(bus, bus->rd_size, -1);
bus->state = I2C_OPER_STARTED;
if (npcm_i2c_is_quick(bus) || bus->wr_size)
npcm_i2c_wr_byte(bus, bus->dest_addr);
else
npcm_i2c_wr_byte(bus, bus->dest_addr | BIT(0));
/* SDA interrupt, after start\restart */
} else {
if (NPCM_I2CST_XMIT & i2cst) {
bus->operation = I2C_WRITE_OPER;
npcm_i2c_irq_master_handler_write(bus);
} else {
bus->operation = I2C_READ_OPER;
npcm_i2c_irq_master_handler_read(bus);
}
}
}
static int npcm_i2c_int_master_handler(struct npcm_i2c *bus)
{
u8 i2cst;
int ret = -EIO;
i2cst = ioread8(bus->reg + NPCM_I2CST);
if (FIELD_GET(NPCM_I2CST_NMATCH, i2cst)) {
npcm_i2c_irq_handle_nmatch(bus);
return 0;
}
/* A NACK has occurred */
if (FIELD_GET(NPCM_I2CST_NEGACK, i2cst)) {
npcm_i2c_irq_handle_nack(bus);
return 0;
}
/* Master mode: a Bus Error has been identified */
if (FIELD_GET(NPCM_I2CST_BER, i2cst)) {
npcm_i2c_irq_handle_ber(bus);
return 0;
}
/* EOB: a master End Of Busy (meaning STOP completed) */
if ((FIELD_GET(NPCM_I2CCTL1_EOBINTE,
ioread8(bus->reg + NPCM_I2CCTL1)) == 1) &&
(FIELD_GET(NPCM_I2CCST3_EO_BUSY,
ioread8(bus->reg + NPCM_I2CCST3)))) {
npcm_i2c_irq_handle_eob(bus);
return 0;
}
/* Address sent and requested stall occurred (Master mode) */
if (FIELD_GET(NPCM_I2CST_STASTR, i2cst)) {
npcm_i2c_irq_handle_stall_after_start(bus);
ret = 0;
}
/* SDA status is set - TX or RX, master */
if (FIELD_GET(NPCM_I2CST_SDAST, i2cst) ||
(bus->fifo_use &&
(npcm_i2c_tx_fifo_empty(bus) || npcm_i2c_rx_fifo_full(bus)))) {
npcm_i2c_irq_handle_sda(bus, i2cst);
ret = 0;
}
return ret;
}
/* recovery using TGCLK functionality of the module */
static int npcm_i2c_recovery_tgclk(struct i2c_adapter *_adap)
{
u8 val;
u8 fif_cts;
bool done = false;
int status = -ENOTRECOVERABLE;
struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap);
/* Allow 3 bytes (27 toggles) to be read from the slave: */
int iter = 27;
if ((npcm_i2c_get_SDA(_adap) == 1) && (npcm_i2c_get_SCL(_adap) == 1)) {
dev_dbg(bus->dev, "bus%d-0x%x recovery skipped, bus not stuck",
bus->num, bus->dest_addr);
npcm_i2c_reset(bus);
return 0;
}
npcm_i2c_int_enable(bus, false);
npcm_i2c_disable(bus);
npcm_i2c_enable(bus);
iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
npcm_i2c_clear_tx_fifo(bus);
npcm_i2c_clear_rx_fifo(bus);
iowrite8(0, bus->reg + NPCM_I2CRXF_CTL);
iowrite8(0, bus->reg + NPCM_I2CTXF_CTL);
npcm_i2c_stall_after_start(bus, false);
/* select bank 1 for FIFO regs */
npcm_i2c_select_bank(bus, I2C_BANK_1);
/* clear FIFO and relevant status bits. */
fif_cts = ioread8(bus->reg + NPCM_I2CFIF_CTS);
fif_cts &= ~NPCM_I2CFIF_CTS_SLVRSTR;
fif_cts |= NPCM_I2CFIF_CTS_CLR_FIFO;
iowrite8(fif_cts, bus->reg + NPCM_I2CFIF_CTS);
npcm_i2c_set_fifo(bus, -1, 0);
/* Repeat the following sequence until SDA is released */
do {
/* Issue a single SCL toggle */
iowrite8(NPCM_I2CCST_TGSCL, bus->reg + NPCM_I2CCST);
usleep_range(20, 30);
/* If SDA line is inactive (high), stop */
if (npcm_i2c_get_SDA(_adap)) {
done = true;
status = 0;
}
} while (!done && iter--);
/* If SDA line is released: send start-addr-stop, to re-sync. */
if (npcm_i2c_get_SDA(_adap)) {
/* Send an address byte in write direction: */
npcm_i2c_wr_byte(bus, bus->dest_addr);
npcm_i2c_master_start(bus);
/* Wait until START condition is sent */
status = readx_poll_timeout(npcm_i2c_get_SCL, _adap, val, !val,
20, 200);
/* If START condition was sent */
if (npcm_i2c_is_master(bus) > 0) {
usleep_range(20, 30);
npcm_i2c_master_stop(bus);
usleep_range(200, 500);
}
}
npcm_i2c_reset(bus);
npcm_i2c_int_enable(bus, true);
if ((npcm_i2c_get_SDA(_adap) == 1) && (npcm_i2c_get_SCL(_adap) == 1))
status = 0;
else
status = -ENOTRECOVERABLE;
if (status) {
if (bus->rec_fail_cnt < ULLONG_MAX)
bus->rec_fail_cnt++;
} else {
if (bus->rec_succ_cnt < ULLONG_MAX)
bus->rec_succ_cnt++;
}
return status;
}
/* recovery using bit banging functionality of the module */
static void npcm_i2c_recovery_init(struct i2c_adapter *_adap)
{
struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap);
struct i2c_bus_recovery_info *rinfo = &bus->rinfo;
rinfo->recover_bus = npcm_i2c_recovery_tgclk;
/*
* npcm i2c HW allows direct reading of SCL and SDA.
* However, it does not support setting SCL and SDA directly.
* The recovery function can toggle SCL when SDA is low (but not set)
* Getter functions used internally, and can be used externally.
*/
rinfo->get_scl = npcm_i2c_get_SCL;
rinfo->get_sda = npcm_i2c_get_SDA;
_adap->bus_recovery_info = rinfo;
}
/* SCLFRQ min/max field values */
#define SCLFRQ_MIN 10
#define SCLFRQ_MAX 511
#define clk_coef(freq, mul) DIV_ROUND_UP((freq) * (mul), 1000000)
/*
* npcm_i2c_init_clk: init HW timing parameters.
* NPCM7XX i2c module timing parameters are dependent on module core clk (APB)
* and bus frequency.
* 100kHz bus requires tSCL = 4 * SCLFRQ * tCLK. LT and HT are symmetric.
* 400kHz bus requires asymmetric HT and LT. A different equation is recommended
* by the HW designer, given core clock range (equations in comments below).
*
*/
static int npcm_i2c_init_clk(struct npcm_i2c *bus, u32 bus_freq_hz)
{
u32 k1 = 0;
u32 k2 = 0;
u8 dbnct = 0;
u32 sclfrq = 0;
u8 hldt = 7;
u8 fast_mode = 0;
u32 src_clk_khz;
u32 bus_freq_khz;
src_clk_khz = bus->apb_clk / 1000;
bus_freq_khz = bus_freq_hz / 1000;
bus->bus_freq = bus_freq_hz;
/* 100KHz and below: */
if (bus_freq_hz <= I2C_MAX_STANDARD_MODE_FREQ) {
sclfrq = src_clk_khz / (bus_freq_khz * 4);
if (sclfrq < SCLFRQ_MIN || sclfrq > SCLFRQ_MAX)
return -EDOM;
if (src_clk_khz >= 40000)
hldt = 17;
else if (src_clk_khz >= 12500)
hldt = 15;
else
hldt = 7;
}
/* 400KHz: */
else if (bus_freq_hz <= I2C_MAX_FAST_MODE_FREQ) {
sclfrq = 0;
fast_mode = I2CCTL3_400K_MODE;
if (src_clk_khz < 7500)
/* 400KHZ cannot be supported for core clock < 7.5MHz */
return -EDOM;
else if (src_clk_khz >= 50000) {
k1 = 80;
k2 = 48;
hldt = 12;
dbnct = 7;
}
/* Master or Slave with frequency > 25MHz */
else if (src_clk_khz > 25000) {
hldt = clk_coef(src_clk_khz, 300) + 7;
k1 = clk_coef(src_clk_khz, 1600);
k2 = clk_coef(src_clk_khz, 900);
}
}
/* 1MHz: */
else if (bus_freq_hz <= I2C_MAX_FAST_MODE_PLUS_FREQ) {
sclfrq = 0;
fast_mode = I2CCTL3_400K_MODE;
/* 1MHZ cannot be supported for core clock < 24 MHz */
if (src_clk_khz < 24000)
return -EDOM;
k1 = clk_coef(src_clk_khz, 620);
k2 = clk_coef(src_clk_khz, 380);
/* Core clk > 40 MHz */
if (src_clk_khz > 40000) {
/*
* Set HLDT:
* SDA hold time: (HLDT-7) * T(CLK) >= 120
* HLDT = 120/T(CLK) + 7 = 120 * FREQ(CLK) + 7
*/
hldt = clk_coef(src_clk_khz, 120) + 7;
} else {
hldt = 7;
dbnct = 2;
}
}
/* Frequency larger than 1 MHz is not supported */
else
return -EINVAL;
if (bus_freq_hz >= I2C_MAX_FAST_MODE_FREQ) {
k1 = round_up(k1, 2);
k2 = round_up(k2 + 1, 2);
if (k1 < SCLFRQ_MIN || k1 > SCLFRQ_MAX ||
k2 < SCLFRQ_MIN || k2 > SCLFRQ_MAX)
return -EDOM;
}
/* write sclfrq value. bits [6:0] are in I2CCTL2 reg */
iowrite8(FIELD_PREP(I2CCTL2_SCLFRQ6_0, sclfrq & 0x7F),
bus->reg + NPCM_I2CCTL2);
/* bits [8:7] are in I2CCTL3 reg */
iowrite8(fast_mode | FIELD_PREP(I2CCTL3_SCLFRQ8_7, (sclfrq >> 7) & 0x3),
bus->reg + NPCM_I2CCTL3);
/* Select Bank 0 to access NPCM_I2CCTL4/NPCM_I2CCTL5 */
npcm_i2c_select_bank(bus, I2C_BANK_0);
if (bus_freq_hz >= I2C_MAX_FAST_MODE_FREQ) {
/*
* Set SCL Low/High Time:
* k1 = 2 * SCLLT7-0 -> Low Time = k1 / 2
* k2 = 2 * SCLLT7-0 -> High Time = k2 / 2
*/
iowrite8(k1 / 2, bus->reg + NPCM_I2CSCLLT);
iowrite8(k2 / 2, bus->reg + NPCM_I2CSCLHT);
iowrite8(dbnct, bus->reg + NPCM_I2CCTL5);
}
iowrite8(hldt, bus->reg + NPCM_I2CCTL4);
/* Return to Bank 1, and stay there by default: */
npcm_i2c_select_bank(bus, I2C_BANK_1);
return 0;
}
static int npcm_i2c_init_module(struct npcm_i2c *bus, enum i2c_mode mode,
u32 bus_freq_hz)
{
u8 val;
int ret;
/* Check whether module already enabled or frequency is out of bounds */
if ((bus->state != I2C_DISABLE && bus->state != I2C_IDLE) ||
bus_freq_hz < I2C_FREQ_MIN_HZ || bus_freq_hz > I2C_FREQ_MAX_HZ)
return -EINVAL;
npcm_i2c_int_enable(bus, false);
npcm_i2c_disable(bus);
/* Configure FIFO mode : */
if (FIELD_GET(I2C_VER_FIFO_EN, ioread8(bus->reg + I2C_VER))) {
bus->fifo_use = true;
npcm_i2c_select_bank(bus, I2C_BANK_0);
val = ioread8(bus->reg + NPCM_I2CFIF_CTL);
val |= NPCM_I2CFIF_CTL_FIFO_EN;
iowrite8(val, bus->reg + NPCM_I2CFIF_CTL);
npcm_i2c_select_bank(bus, I2C_BANK_1);
} else {
bus->fifo_use = false;
}
/* Configure I2C module clock frequency */
ret = npcm_i2c_init_clk(bus, bus_freq_hz);
if (ret) {
dev_err(bus->dev, "npcm_i2c_init_clk failed\n");
return ret;
}
/* Enable module (before configuring CTL1) */
npcm_i2c_enable(bus);
bus->state = I2C_IDLE;
val = ioread8(bus->reg + NPCM_I2CCTL1);
val = (val | NPCM_I2CCTL1_NMINTE) & ~NPCM_I2CCTL1_RWS;
iowrite8(val, bus->reg + NPCM_I2CCTL1);
npcm_i2c_reset(bus);
/* Check HW is OK: SDA and SCL should be high at this point. */
if ((npcm_i2c_get_SDA(&bus->adap) == 0) || (npcm_i2c_get_SCL(&bus->adap) == 0)) {
dev_err(bus->dev, "I2C%d init fail: lines are low\n", bus->num);
dev_err(bus->dev, "SDA=%d SCL=%d\n", npcm_i2c_get_SDA(&bus->adap),
npcm_i2c_get_SCL(&bus->adap));
return -ENXIO;
}
npcm_i2c_int_enable(bus, true);
return 0;
}
static int __npcm_i2c_init(struct npcm_i2c *bus, struct platform_device *pdev)
{
u32 clk_freq_hz;
int ret;
/* Initialize the internal data structures */
bus->state = I2C_DISABLE;
bus->master_or_slave = I2C_SLAVE;
bus->int_time_stamp = 0;
#if IS_ENABLED(CONFIG_I2C_SLAVE)
bus->slave = NULL;
#endif
ret = device_property_read_u32(&pdev->dev, "clock-frequency",
&clk_freq_hz);
if (ret) {
dev_info(&pdev->dev, "Could not read clock-frequency property");
clk_freq_hz = I2C_MAX_STANDARD_MODE_FREQ;
}
ret = npcm_i2c_init_module(bus, I2C_MASTER, clk_freq_hz);
if (ret) {
dev_err(&pdev->dev, "npcm_i2c_init_module failed\n");
return ret;
}
return 0;
}
static irqreturn_t npcm_i2c_bus_irq(int irq, void *dev_id)
{
struct npcm_i2c *bus = dev_id;
if (npcm_i2c_is_master(bus))
bus->master_or_slave = I2C_MASTER;
if (bus->master_or_slave == I2C_MASTER) {
bus->int_time_stamp = jiffies;
if (!npcm_i2c_int_master_handler(bus))
return IRQ_HANDLED;
}
#if IS_ENABLED(CONFIG_I2C_SLAVE)
if (bus->slave) {
bus->master_or_slave = I2C_SLAVE;
if (npcm_i2c_int_slave_handler(bus))
return IRQ_HANDLED;
}
#endif
/* Clear status bits for spurious interrupts */
npcm_i2c_clear_master_status(bus);
return IRQ_HANDLED;
}
static bool npcm_i2c_master_start_xmit(struct npcm_i2c *bus,
u8 slave_addr, u16 nwrite, u16 nread,
u8 *write_data, u8 *read_data,
bool use_PEC, bool use_read_block)
{
if (bus->state != I2C_IDLE) {
bus->cmd_err = -EBUSY;
return false;
}
bus->dest_addr = slave_addr << 1;
bus->wr_buf = write_data;
bus->wr_size = nwrite;
bus->wr_ind = 0;
bus->rd_buf = read_data;
bus->rd_size = nread;
bus->rd_ind = 0;
bus->PEC_use = 0;
/* for tx PEC is appended to buffer from i2c IF. PEC flag is ignored */
if (nread)
bus->PEC_use = use_PEC;
bus->read_block_use = use_read_block;
if (nread && !nwrite)
bus->operation = I2C_READ_OPER;
else
bus->operation = I2C_WRITE_OPER;
if (bus->fifo_use) {
u8 i2cfif_cts;
npcm_i2c_select_bank(bus, I2C_BANK_1);
/* clear FIFO and relevant status bits. */
i2cfif_cts = ioread8(bus->reg + NPCM_I2CFIF_CTS);
i2cfif_cts &= ~NPCM_I2CFIF_CTS_SLVRSTR;
i2cfif_cts |= NPCM_I2CFIF_CTS_CLR_FIFO;
iowrite8(i2cfif_cts, bus->reg + NPCM_I2CFIF_CTS);
}
bus->state = I2C_IDLE;
npcm_i2c_stall_after_start(bus, true);
npcm_i2c_master_start(bus);
return true;
}
static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
int num)
{
struct npcm_i2c *bus = container_of(adap, struct npcm_i2c, adap);
struct i2c_msg *msg0, *msg1;
unsigned long time_left, flags;
u16 nwrite, nread;
u8 *write_data, *read_data;
u8 slave_addr;
unsigned long timeout;
bool read_block = false;
bool read_PEC = false;
u8 bus_busy;
unsigned long timeout_usec;
if (bus->state == I2C_DISABLE) {
dev_err(bus->dev, "I2C%d module is disabled", bus->num);
return -EINVAL;
}
msg0 = &msgs[0];
slave_addr = msg0->addr;
if (msg0->flags & I2C_M_RD) { /* read */
nwrite = 0;
write_data = NULL;
read_data = msg0->buf;
if (msg0->flags & I2C_M_RECV_LEN) {
nread = 1;
read_block = true;
if (msg0->flags & I2C_CLIENT_PEC)
read_PEC = true;
} else {
nread = msg0->len;
}
} else { /* write */
nwrite = msg0->len;
write_data = msg0->buf;
nread = 0;
read_data = NULL;
if (num == 2) {
msg1 = &msgs[1];
read_data = msg1->buf;
if (msg1->flags & I2C_M_RECV_LEN) {
nread = 1;
read_block = true;
if (msg1->flags & I2C_CLIENT_PEC)
read_PEC = true;
} else {
nread = msg1->len;
read_block = false;
}
}
}
/*
* Adaptive TimeOut: estimated time in usec + 100% margin:
* 2: double the timeout for clock stretching case
* 9: bits per transaction (including the ack/nack)
*/
timeout_usec = (2 * 9 * USEC_PER_SEC / bus->bus_freq) * (2 + nread + nwrite);
timeout = max_t(unsigned long, bus->adap.timeout, usecs_to_jiffies(timeout_usec));
if (nwrite >= 32 * 1024 || nread >= 32 * 1024) {
dev_err(bus->dev, "i2c%d buffer too big\n", bus->num);
return -EINVAL;
}
time_left = jiffies + timeout + 1;
do {
/*
* we must clear slave address immediately when the bus is not
* busy, so we spinlock it, but we don't keep the lock for the
* entire while since it is too long.
*/
spin_lock_irqsave(&bus->lock, flags);
bus_busy = ioread8(bus->reg + NPCM_I2CCST) & NPCM_I2CCST_BB;
#if IS_ENABLED(CONFIG_I2C_SLAVE)
if (!bus_busy && bus->slave)
iowrite8((bus->slave->addr & 0x7F),
bus->reg + NPCM_I2CADDR1);
#endif
spin_unlock_irqrestore(&bus->lock, flags);
} while (time_is_after_jiffies(time_left) && bus_busy);
if (bus_busy) {
iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
npcm_i2c_reset(bus);
i2c_recover_bus(adap);
return -EAGAIN;
}
npcm_i2c_init_params(bus);
bus->dest_addr = slave_addr;
bus->msgs = msgs;
bus->msgs_num = num;
bus->cmd_err = 0;
bus->read_block_use = read_block;
reinit_completion(&bus->cmd_complete);
npcm_i2c_int_enable(bus, true);
if (npcm_i2c_master_start_xmit(bus, slave_addr, nwrite, nread,
write_data, read_data, read_PEC,
read_block)) {
time_left = wait_for_completion_timeout(&bus->cmd_complete,
timeout);
if (time_left == 0) {
if (bus->timeout_cnt < ULLONG_MAX)
bus->timeout_cnt++;
if (bus->master_or_slave == I2C_MASTER) {
i2c_recover_bus(adap);
bus->cmd_err = -EIO;
bus->state = I2C_IDLE;
}
}
}
/* if there was BER, check if need to recover the bus: */
if (bus->cmd_err == -EAGAIN)
bus->cmd_err = i2c_recover_bus(adap);
/*
* After any type of error, check if LAST bit is still set,
* due to a HW issue.
* It cannot be cleared without resetting the module.
*/
else if (bus->cmd_err &&
(bus->data->rxf_ctl_last_pec & ioread8(bus->reg + NPCM_I2CRXF_CTL)))
npcm_i2c_reset(bus);
/* After any xfer, successful or not, stall and EOB must be disabled */
npcm_i2c_stall_after_start(bus, false);
npcm_i2c_eob_int(bus, false);
#if IS_ENABLED(CONFIG_I2C_SLAVE)
/* reenable slave if it was enabled */
if (bus->slave)
iowrite8((bus->slave->addr & 0x7F) | NPCM_I2CADDR_SAEN,
bus->reg + NPCM_I2CADDR1);
#else
npcm_i2c_int_enable(bus, false);
#endif
return bus->cmd_err;
}
static u32 npcm_i2c_functionality(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C |
I2C_FUNC_SMBUS_EMUL |
I2C_FUNC_SMBUS_BLOCK_DATA |
I2C_FUNC_SMBUS_PEC |
I2C_FUNC_SLAVE;
}
static const struct i2c_adapter_quirks npcm_i2c_quirks = {
.max_read_len = 32768,
.max_write_len = 32768,
.flags = I2C_AQ_COMB_WRITE_THEN_READ,
};
static const struct i2c_algorithm npcm_i2c_algo = {
.master_xfer = npcm_i2c_master_xfer,
.functionality = npcm_i2c_functionality,
#if IS_ENABLED(CONFIG_I2C_SLAVE)
.reg_slave = npcm_i2c_reg_slave,
.unreg_slave = npcm_i2c_unreg_slave,
#endif
};
/* i2c debugfs directory: used to keep health monitor of i2c devices */
static struct dentry *npcm_i2c_debugfs_dir;
static void npcm_i2c_init_debugfs(struct platform_device *pdev,
struct npcm_i2c *bus)
{
struct dentry *d;
if (!npcm_i2c_debugfs_dir)
return;
d = debugfs_create_dir(dev_name(&pdev->dev), npcm_i2c_debugfs_dir);
if (IS_ERR_OR_NULL(d))
return;
debugfs_create_u64("ber_cnt", 0444, d, &bus->ber_cnt);
debugfs_create_u64("nack_cnt", 0444, d, &bus->nack_cnt);
debugfs_create_u64("rec_succ_cnt", 0444, d, &bus->rec_succ_cnt);
debugfs_create_u64("rec_fail_cnt", 0444, d, &bus->rec_fail_cnt);
debugfs_create_u64("timeout_cnt", 0444, d, &bus->timeout_cnt);
debugfs_create_u64("tx_complete_cnt", 0444, d, &bus->tx_complete_cnt);
bus->debugfs = d;
}
static int npcm_i2c_probe_bus(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
static struct regmap *gcr_regmap;
struct device *dev = &pdev->dev;
struct i2c_adapter *adap;
struct npcm_i2c *bus;
struct clk *i2c_clk;
int irq;
int ret;
bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);
if (!bus)
return -ENOMEM;
bus->dev = &pdev->dev;
bus->data = of_device_get_match_data(dev);
if (!bus->data) {
dev_err(dev, "OF data missing\n");
return -EINVAL;
}
bus->num = of_alias_get_id(pdev->dev.of_node, "i2c");
/* core clk must be acquired to calculate module timing settings */
i2c_clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(i2c_clk))
return PTR_ERR(i2c_clk);
bus->apb_clk = clk_get_rate(i2c_clk);
gcr_regmap = syscon_regmap_lookup_by_phandle(np, "nuvoton,sys-mgr");
if (IS_ERR(gcr_regmap))
gcr_regmap = syscon_regmap_lookup_by_compatible("nuvoton,npcm750-gcr");
if (IS_ERR(gcr_regmap))
return PTR_ERR(gcr_regmap);
regmap_write(gcr_regmap, NPCM_I2CSEGCTL, bus->data->segctl_init_val);
bus->reg = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(bus->reg))
return PTR_ERR(bus->reg);
spin_lock_init(&bus->lock);
init_completion(&bus->cmd_complete);
adap = &bus->adap;
adap->owner = THIS_MODULE;
adap->retries = 3;
adap->timeout = msecs_to_jiffies(35);
adap->algo = &npcm_i2c_algo;
adap->quirks = &npcm_i2c_quirks;
adap->algo_data = bus;
adap->dev.parent = &pdev->dev;
adap->dev.of_node = pdev->dev.of_node;
adap->nr = pdev->id;
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
ret = devm_request_irq(bus->dev, irq, npcm_i2c_bus_irq, 0,
dev_name(bus->dev), bus);
if (ret)
return ret;
ret = __npcm_i2c_init(bus, pdev);
if (ret)
return ret;
npcm_i2c_recovery_init(adap);
i2c_set_adapdata(adap, bus);
snprintf(bus->adap.name, sizeof(bus->adap.name), "npcm_i2c_%d",
bus->num);
ret = i2c_add_numbered_adapter(&bus->adap);
if (ret)
return ret;
platform_set_drvdata(pdev, bus);
npcm_i2c_init_debugfs(pdev, bus);
return 0;
}
static void npcm_i2c_remove_bus(struct platform_device *pdev)
{
unsigned long lock_flags;
struct npcm_i2c *bus = platform_get_drvdata(pdev);
debugfs_remove_recursive(bus->debugfs);
spin_lock_irqsave(&bus->lock, lock_flags);
npcm_i2c_disable(bus);
spin_unlock_irqrestore(&bus->lock, lock_flags);
i2c_del_adapter(&bus->adap);
}
static const struct of_device_id npcm_i2c_bus_of_table[] = {
{ .compatible = "nuvoton,npcm750-i2c", .data = &npxm7xx_i2c_data },
{ .compatible = "nuvoton,npcm845-i2c", .data = &npxm8xx_i2c_data },
{}
};
MODULE_DEVICE_TABLE(of, npcm_i2c_bus_of_table);
static struct platform_driver npcm_i2c_bus_driver = {
.probe = npcm_i2c_probe_bus,
.remove_new = npcm_i2c_remove_bus,
.driver = {
.name = "nuvoton-i2c",
.of_match_table = npcm_i2c_bus_of_table,
}
};
static int __init npcm_i2c_init(void)
{
int ret;
npcm_i2c_debugfs_dir = debugfs_create_dir("npcm_i2c", NULL);
ret = platform_driver_register(&npcm_i2c_bus_driver);
if (ret) {
debugfs_remove_recursive(npcm_i2c_debugfs_dir);
return ret;
}
return 0;
}
module_init(npcm_i2c_init);
static void __exit npcm_i2c_exit(void)
{
platform_driver_unregister(&npcm_i2c_bus_driver);
debugfs_remove_recursive(npcm_i2c_debugfs_dir);
}
module_exit(npcm_i2c_exit);
MODULE_AUTHOR("Avi Fishman <avi.fishman@gmail.com>");
MODULE_AUTHOR("Tali Perry <tali.perry@nuvoton.com>");
MODULE_AUTHOR("Tyrone Ting <kfting@nuvoton.com>");
MODULE_DESCRIPTION("Nuvoton I2C Bus Driver");
MODULE_LICENSE("GPL v2");
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