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linux/drivers/i2c/busses/i2c-stm32f7.c
Alain Volmat c8062d11e2 i2c: stm32f7: add SMBus-Alert support 
Add support for the SMBus-Alert protocol to the STM32F7 that has
dedicated control and status logic.

If SMBus-Alert is used, the SMBALERT# pin must be configured as alternate
function for I2C Alert.

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@foss.st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
2021-05-25 21:48:19 +02:00

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// SPDX-License-Identifier: GPL-2.0
/*
* Driver for STMicroelectronics STM32F7 I2C controller
*
* This I2C controller is described in the STM32F75xxx and STM32F74xxx Soc
* reference manual.
* Please see below a link to the documentation:
* http://www.st.com/resource/en/reference_manual/dm00124865.pdf
*
* Copyright (C) M'boumba Cedric Madianga 2017
* Copyright (C) STMicroelectronics 2017
* Author: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
*
* This driver is based on i2c-stm32f4.c
*
*/
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/i2c-smbus.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pinctrl/consumer.h>
#include <linux/pm_runtime.h>
#include <linux/pm_wakeirq.h>
#include <linux/regmap.h>
#include <linux/reset.h>
#include <linux/slab.h>
#include "i2c-stm32.h"
/* STM32F7 I2C registers */
#define STM32F7_I2C_CR1 0x00
#define STM32F7_I2C_CR2 0x04
#define STM32F7_I2C_OAR1 0x08
#define STM32F7_I2C_OAR2 0x0C
#define STM32F7_I2C_PECR 0x20
#define STM32F7_I2C_TIMINGR 0x10
#define STM32F7_I2C_ISR 0x18
#define STM32F7_I2C_ICR 0x1C
#define STM32F7_I2C_RXDR 0x24
#define STM32F7_I2C_TXDR 0x28
/* STM32F7 I2C control 1 */
#define STM32F7_I2C_CR1_PECEN BIT(23)
#define STM32F7_I2C_CR1_ALERTEN BIT(22)
#define STM32F7_I2C_CR1_SMBHEN BIT(20)
#define STM32F7_I2C_CR1_WUPEN BIT(18)
#define STM32F7_I2C_CR1_SBC BIT(16)
#define STM32F7_I2C_CR1_RXDMAEN BIT(15)
#define STM32F7_I2C_CR1_TXDMAEN BIT(14)
#define STM32F7_I2C_CR1_ANFOFF BIT(12)
#define STM32F7_I2C_CR1_DNF_MASK GENMASK(11, 8)
#define STM32F7_I2C_CR1_DNF(n) (((n) & 0xf) << 8)
#define STM32F7_I2C_CR1_ERRIE BIT(7)
#define STM32F7_I2C_CR1_TCIE BIT(6)
#define STM32F7_I2C_CR1_STOPIE BIT(5)
#define STM32F7_I2C_CR1_NACKIE BIT(4)
#define STM32F7_I2C_CR1_ADDRIE BIT(3)
#define STM32F7_I2C_CR1_RXIE BIT(2)
#define STM32F7_I2C_CR1_TXIE BIT(1)
#define STM32F7_I2C_CR1_PE BIT(0)
#define STM32F7_I2C_ALL_IRQ_MASK (STM32F7_I2C_CR1_ERRIE \
| STM32F7_I2C_CR1_TCIE \
| STM32F7_I2C_CR1_STOPIE \
| STM32F7_I2C_CR1_NACKIE \
| STM32F7_I2C_CR1_RXIE \
| STM32F7_I2C_CR1_TXIE)
#define STM32F7_I2C_XFER_IRQ_MASK (STM32F7_I2C_CR1_TCIE \
| STM32F7_I2C_CR1_STOPIE \
| STM32F7_I2C_CR1_NACKIE \
| STM32F7_I2C_CR1_RXIE \
| STM32F7_I2C_CR1_TXIE)
/* STM32F7 I2C control 2 */
#define STM32F7_I2C_CR2_PECBYTE BIT(26)
#define STM32F7_I2C_CR2_RELOAD BIT(24)
#define STM32F7_I2C_CR2_NBYTES_MASK GENMASK(23, 16)
#define STM32F7_I2C_CR2_NBYTES(n) (((n) & 0xff) << 16)
#define STM32F7_I2C_CR2_NACK BIT(15)
#define STM32F7_I2C_CR2_STOP BIT(14)
#define STM32F7_I2C_CR2_START BIT(13)
#define STM32F7_I2C_CR2_HEAD10R BIT(12)
#define STM32F7_I2C_CR2_ADD10 BIT(11)
#define STM32F7_I2C_CR2_RD_WRN BIT(10)
#define STM32F7_I2C_CR2_SADD10_MASK GENMASK(9, 0)
#define STM32F7_I2C_CR2_SADD10(n) (((n) & \
STM32F7_I2C_CR2_SADD10_MASK))
#define STM32F7_I2C_CR2_SADD7_MASK GENMASK(7, 1)
#define STM32F7_I2C_CR2_SADD7(n) (((n) & 0x7f) << 1)
/* STM32F7 I2C Own Address 1 */
#define STM32F7_I2C_OAR1_OA1EN BIT(15)
#define STM32F7_I2C_OAR1_OA1MODE BIT(10)
#define STM32F7_I2C_OAR1_OA1_10_MASK GENMASK(9, 0)
#define STM32F7_I2C_OAR1_OA1_10(n) (((n) & \
STM32F7_I2C_OAR1_OA1_10_MASK))
#define STM32F7_I2C_OAR1_OA1_7_MASK GENMASK(7, 1)
#define STM32F7_I2C_OAR1_OA1_7(n) (((n) & 0x7f) << 1)
#define STM32F7_I2C_OAR1_MASK (STM32F7_I2C_OAR1_OA1_7_MASK \
| STM32F7_I2C_OAR1_OA1_10_MASK \
| STM32F7_I2C_OAR1_OA1EN \
| STM32F7_I2C_OAR1_OA1MODE)
/* STM32F7 I2C Own Address 2 */
#define STM32F7_I2C_OAR2_OA2EN BIT(15)
#define STM32F7_I2C_OAR2_OA2MSK_MASK GENMASK(10, 8)
#define STM32F7_I2C_OAR2_OA2MSK(n) (((n) & 0x7) << 8)
#define STM32F7_I2C_OAR2_OA2_7_MASK GENMASK(7, 1)
#define STM32F7_I2C_OAR2_OA2_7(n) (((n) & 0x7f) << 1)
#define STM32F7_I2C_OAR2_MASK (STM32F7_I2C_OAR2_OA2MSK_MASK \
| STM32F7_I2C_OAR2_OA2_7_MASK \
| STM32F7_I2C_OAR2_OA2EN)
/* STM32F7 I2C Interrupt Status */
#define STM32F7_I2C_ISR_ADDCODE_MASK GENMASK(23, 17)
#define STM32F7_I2C_ISR_ADDCODE_GET(n) \
(((n) & STM32F7_I2C_ISR_ADDCODE_MASK) >> 17)
#define STM32F7_I2C_ISR_DIR BIT(16)
#define STM32F7_I2C_ISR_BUSY BIT(15)
#define STM32F7_I2C_ISR_ALERT BIT(13)
#define STM32F7_I2C_ISR_PECERR BIT(11)
#define STM32F7_I2C_ISR_ARLO BIT(9)
#define STM32F7_I2C_ISR_BERR BIT(8)
#define STM32F7_I2C_ISR_TCR BIT(7)
#define STM32F7_I2C_ISR_TC BIT(6)
#define STM32F7_I2C_ISR_STOPF BIT(5)
#define STM32F7_I2C_ISR_NACKF BIT(4)
#define STM32F7_I2C_ISR_ADDR BIT(3)
#define STM32F7_I2C_ISR_RXNE BIT(2)
#define STM32F7_I2C_ISR_TXIS BIT(1)
#define STM32F7_I2C_ISR_TXE BIT(0)
/* STM32F7 I2C Interrupt Clear */
#define STM32F7_I2C_ICR_ALERTCF BIT(13)
#define STM32F7_I2C_ICR_PECCF BIT(11)
#define STM32F7_I2C_ICR_ARLOCF BIT(9)
#define STM32F7_I2C_ICR_BERRCF BIT(8)
#define STM32F7_I2C_ICR_STOPCF BIT(5)
#define STM32F7_I2C_ICR_NACKCF BIT(4)
#define STM32F7_I2C_ICR_ADDRCF BIT(3)
/* STM32F7 I2C Timing */
#define STM32F7_I2C_TIMINGR_PRESC(n) (((n) & 0xf) << 28)
#define STM32F7_I2C_TIMINGR_SCLDEL(n) (((n) & 0xf) << 20)
#define STM32F7_I2C_TIMINGR_SDADEL(n) (((n) & 0xf) << 16)
#define STM32F7_I2C_TIMINGR_SCLH(n) (((n) & 0xff) << 8)
#define STM32F7_I2C_TIMINGR_SCLL(n) ((n) & 0xff)
#define STM32F7_I2C_MAX_LEN 0xff
#define STM32F7_I2C_DMA_LEN_MIN 0x16
enum {
STM32F7_SLAVE_HOSTNOTIFY,
STM32F7_SLAVE_7_10_BITS_ADDR,
STM32F7_SLAVE_7_BITS_ADDR,
STM32F7_I2C_MAX_SLAVE
};
#define STM32F7_I2C_DNF_DEFAULT 0
#define STM32F7_I2C_DNF_MAX 15
#define STM32F7_I2C_ANALOG_FILTER_DELAY_MIN 50 /* ns */
#define STM32F7_I2C_ANALOG_FILTER_DELAY_MAX 260 /* ns */
#define STM32F7_I2C_RISE_TIME_DEFAULT 25 /* ns */
#define STM32F7_I2C_FALL_TIME_DEFAULT 10 /* ns */
#define STM32F7_PRESC_MAX BIT(4)
#define STM32F7_SCLDEL_MAX BIT(4)
#define STM32F7_SDADEL_MAX BIT(4)
#define STM32F7_SCLH_MAX BIT(8)
#define STM32F7_SCLL_MAX BIT(8)
#define STM32F7_AUTOSUSPEND_DELAY (HZ / 100)
/**
* struct stm32f7_i2c_regs - i2c f7 registers backup
* @cr1: Control register 1
* @cr2: Control register 2
* @oar1: Own address 1 register
* @oar2: Own address 2 register
* @tmgr: Timing register
*/
struct stm32f7_i2c_regs {
u32 cr1;
u32 cr2;
u32 oar1;
u32 oar2;
u32 tmgr;
};
/**
* struct stm32f7_i2c_spec - private i2c specification timing
* @rate: I2C bus speed (Hz)
* @fall_max: Max fall time of both SDA and SCL signals (ns)
* @rise_max: Max rise time of both SDA and SCL signals (ns)
* @hddat_min: Min data hold time (ns)
* @vddat_max: Max data valid time (ns)
* @sudat_min: Min data setup time (ns)
* @l_min: Min low period of the SCL clock (ns)
* @h_min: Min high period of the SCL clock (ns)
*/
struct stm32f7_i2c_spec {
u32 rate;
u32 fall_max;
u32 rise_max;
u32 hddat_min;
u32 vddat_max;
u32 sudat_min;
u32 l_min;
u32 h_min;
};
/**
* struct stm32f7_i2c_setup - private I2C timing setup parameters
* @speed_freq: I2C speed frequency (Hz)
* @clock_src: I2C clock source frequency (Hz)
* @rise_time: Rise time (ns)
* @fall_time: Fall time (ns)
* @fmp_clr_offset: Fast Mode Plus clear register offset from set register
*/
struct stm32f7_i2c_setup {
u32 speed_freq;
u32 clock_src;
u32 rise_time;
u32 fall_time;
u32 fmp_clr_offset;
};
/**
* struct stm32f7_i2c_timings - private I2C output parameters
* @node: List entry
* @presc: Prescaler value
* @scldel: Data setup time
* @sdadel: Data hold time
* @sclh: SCL high period (master mode)
* @scll: SCL low period (master mode)
*/
struct stm32f7_i2c_timings {
struct list_head node;
u8 presc;
u8 scldel;
u8 sdadel;
u8 sclh;
u8 scll;
};
/**
* struct stm32f7_i2c_msg - client specific data
* @addr: 8-bit or 10-bit slave addr, including r/w bit
* @count: number of bytes to be transferred
* @buf: data buffer
* @result: result of the transfer
* @stop: last I2C msg to be sent, i.e. STOP to be generated
* @smbus: boolean to know if the I2C IP is used in SMBus mode
* @size: type of SMBus protocol
* @read_write: direction of SMBus protocol
* SMBus block read and SMBus block write - block read process call protocols
* @smbus_buf: buffer to be used for SMBus protocol transfer. It will
* contain a maximum of 32 bytes of data + byte command + byte count + PEC
* This buffer has to be 32-bit aligned to be compliant with memory address
* register in DMA mode.
*/
struct stm32f7_i2c_msg {
u16 addr;
u32 count;
u8 *buf;
int result;
bool stop;
bool smbus;
int size;
char read_write;
u8 smbus_buf[I2C_SMBUS_BLOCK_MAX + 3] __aligned(4);
};
/**
* struct stm32f7_i2c_alert - SMBus alert specific data
* @setup: platform data for the smbus_alert i2c client
* @ara: I2C slave device used to respond to the SMBus Alert with Alert
* Response Address
*/
struct stm32f7_i2c_alert {
struct i2c_smbus_alert_setup setup;
struct i2c_client *ara;
};
/**
* struct stm32f7_i2c_dev - private data of the controller
* @adap: I2C adapter for this controller
* @dev: device for this controller
* @base: virtual memory area
* @complete: completion of I2C message
* @clk: hw i2c clock
* @bus_rate: I2C clock frequency of the controller
* @msg: Pointer to data to be written
* @msg_num: number of I2C messages to be executed
* @msg_id: message identifiant
* @f7_msg: customized i2c msg for driver usage
* @setup: I2C timing input setup
* @timing: I2C computed timings
* @slave: list of slave devices registered on the I2C bus
* @slave_running: slave device currently used
* @backup_regs: backup of i2c controller registers (for suspend/resume)
* @slave_dir: transfer direction for the current slave device
* @master_mode: boolean to know in which mode the I2C is running (master or
* slave)
* @dma: dma data
* @use_dma: boolean to know if dma is used in the current transfer
* @regmap: holds SYSCFG phandle for Fast Mode Plus bits
* @fmp_sreg: register address for setting Fast Mode Plus bits
* @fmp_creg: register address for clearing Fast Mode Plus bits
* @fmp_mask: mask for Fast Mode Plus bits in set register
* @wakeup_src: boolean to know if the device is a wakeup source
* @smbus_mode: states that the controller is configured in SMBus mode
* @host_notify_client: SMBus host-notify client
* @analog_filter: boolean to indicate enabling of the analog filter
* @dnf_dt: value of digital filter requested via dt
* @dnf: value of digital filter to apply
* @alert: SMBus alert specific data
*/
struct stm32f7_i2c_dev {
struct i2c_adapter adap;
struct device *dev;
void __iomem *base;
struct completion complete;
struct clk *clk;
unsigned int bus_rate;
struct i2c_msg *msg;
unsigned int msg_num;
unsigned int msg_id;
struct stm32f7_i2c_msg f7_msg;
struct stm32f7_i2c_setup setup;
struct stm32f7_i2c_timings timing;
struct i2c_client *slave[STM32F7_I2C_MAX_SLAVE];
struct i2c_client *slave_running;
struct stm32f7_i2c_regs backup_regs;
u32 slave_dir;
bool master_mode;
struct stm32_i2c_dma *dma;
bool use_dma;
struct regmap *regmap;
u32 fmp_sreg;
u32 fmp_creg;
u32 fmp_mask;
bool wakeup_src;
bool smbus_mode;
struct i2c_client *host_notify_client;
bool analog_filter;
u32 dnf_dt;
u32 dnf;
struct stm32f7_i2c_alert *alert;
};
/*
* All these values are coming from I2C Specification, Version 6.0, 4th of
* April 2014.
*
* Table10. Characteristics of the SDA and SCL bus lines for Standard, Fast,
* and Fast-mode Plus I2C-bus devices
*/
static struct stm32f7_i2c_spec stm32f7_i2c_specs[] = {
{
.rate = I2C_MAX_STANDARD_MODE_FREQ,
.fall_max = 300,
.rise_max = 1000,
.hddat_min = 0,
.vddat_max = 3450,
.sudat_min = 250,
.l_min = 4700,
.h_min = 4000,
},
{
.rate = I2C_MAX_FAST_MODE_FREQ,
.fall_max = 300,
.rise_max = 300,
.hddat_min = 0,
.vddat_max = 900,
.sudat_min = 100,
.l_min = 1300,
.h_min = 600,
},
{
.rate = I2C_MAX_FAST_MODE_PLUS_FREQ,
.fall_max = 100,
.rise_max = 120,
.hddat_min = 0,
.vddat_max = 450,
.sudat_min = 50,
.l_min = 500,
.h_min = 260,
},
};
static const struct stm32f7_i2c_setup stm32f7_setup = {
.rise_time = STM32F7_I2C_RISE_TIME_DEFAULT,
.fall_time = STM32F7_I2C_FALL_TIME_DEFAULT,
};
static const struct stm32f7_i2c_setup stm32mp15_setup = {
.rise_time = STM32F7_I2C_RISE_TIME_DEFAULT,
.fall_time = STM32F7_I2C_FALL_TIME_DEFAULT,
.fmp_clr_offset = 0x40,
};
static inline void stm32f7_i2c_set_bits(void __iomem *reg, u32 mask)
{
writel_relaxed(readl_relaxed(reg) | mask, reg);
}
static inline void stm32f7_i2c_clr_bits(void __iomem *reg, u32 mask)
{
writel_relaxed(readl_relaxed(reg) & ~mask, reg);
}
static void stm32f7_i2c_disable_irq(struct stm32f7_i2c_dev *i2c_dev, u32 mask)
{
stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1, mask);
}
static struct stm32f7_i2c_spec *stm32f7_get_specs(u32 rate)
{
int i;
for (i = 0; i < ARRAY_SIZE(stm32f7_i2c_specs); i++)
if (rate <= stm32f7_i2c_specs[i].rate)
return &stm32f7_i2c_specs[i];
return ERR_PTR(-EINVAL);
}
#define RATE_MIN(rate) ((rate) * 8 / 10)
static int stm32f7_i2c_compute_timing(struct stm32f7_i2c_dev *i2c_dev,
struct stm32f7_i2c_setup *setup,
struct stm32f7_i2c_timings *output)
{
struct stm32f7_i2c_spec *specs;
u32 p_prev = STM32F7_PRESC_MAX;
u32 i2cclk = DIV_ROUND_CLOSEST(NSEC_PER_SEC,
setup->clock_src);
u32 i2cbus = DIV_ROUND_CLOSEST(NSEC_PER_SEC,
setup->speed_freq);
u32 clk_error_prev = i2cbus;
u32 tsync;
u32 af_delay_min, af_delay_max;
u32 dnf_delay;
u32 clk_min, clk_max;
int sdadel_min, sdadel_max;
int scldel_min;
struct stm32f7_i2c_timings *v, *_v, *s;
struct list_head solutions;
u16 p, l, a, h;
int ret = 0;
specs = stm32f7_get_specs(setup->speed_freq);
if (specs == ERR_PTR(-EINVAL)) {
dev_err(i2c_dev->dev, "speed out of bound {%d}\n",
setup->speed_freq);
return -EINVAL;
}
if ((setup->rise_time > specs->rise_max) ||
(setup->fall_time > specs->fall_max)) {
dev_err(i2c_dev->dev,
"timings out of bound Rise{%d>%d}/Fall{%d>%d}\n",
setup->rise_time, specs->rise_max,
setup->fall_time, specs->fall_max);
return -EINVAL;
}
i2c_dev->dnf = DIV_ROUND_CLOSEST(i2c_dev->dnf_dt, i2cclk);
if (i2c_dev->dnf > STM32F7_I2C_DNF_MAX) {
dev_err(i2c_dev->dev,
"DNF out of bound %d/%d\n",
i2c_dev->dnf * i2cclk, STM32F7_I2C_DNF_MAX * i2cclk);
return -EINVAL;
}
/* Analog and Digital Filters */
af_delay_min =
(i2c_dev->analog_filter ?
STM32F7_I2C_ANALOG_FILTER_DELAY_MIN : 0);
af_delay_max =
(i2c_dev->analog_filter ?
STM32F7_I2C_ANALOG_FILTER_DELAY_MAX : 0);
dnf_delay = i2c_dev->dnf * i2cclk;
sdadel_min = specs->hddat_min + setup->fall_time -
af_delay_min - (i2c_dev->dnf + 3) * i2cclk;
sdadel_max = specs->vddat_max - setup->rise_time -
af_delay_max - (i2c_dev->dnf + 4) * i2cclk;
scldel_min = setup->rise_time + specs->sudat_min;
if (sdadel_min < 0)
sdadel_min = 0;
if (sdadel_max < 0)
sdadel_max = 0;
dev_dbg(i2c_dev->dev, "SDADEL(min/max): %i/%i, SCLDEL(Min): %i\n",
sdadel_min, sdadel_max, scldel_min);
INIT_LIST_HEAD(&solutions);
/* Compute possible values for PRESC, SCLDEL and SDADEL */
for (p = 0; p < STM32F7_PRESC_MAX; p++) {
for (l = 0; l < STM32F7_SCLDEL_MAX; l++) {
u32 scldel = (l + 1) * (p + 1) * i2cclk;
if (scldel < scldel_min)
continue;
for (a = 0; a < STM32F7_SDADEL_MAX; a++) {
u32 sdadel = (a * (p + 1) + 1) * i2cclk;
if (((sdadel >= sdadel_min) &&
(sdadel <= sdadel_max)) &&
(p != p_prev)) {
v = kmalloc(sizeof(*v), GFP_KERNEL);
if (!v) {
ret = -ENOMEM;
goto exit;
}
v->presc = p;
v->scldel = l;
v->sdadel = a;
p_prev = p;
list_add_tail(&v->node,
&solutions);
break;
}
}
if (p_prev == p)
break;
}
}
if (list_empty(&solutions)) {
dev_err(i2c_dev->dev, "no Prescaler solution\n");
ret = -EPERM;
goto exit;
}
tsync = af_delay_min + dnf_delay + (2 * i2cclk);
s = NULL;
clk_max = NSEC_PER_SEC / RATE_MIN(setup->speed_freq);
clk_min = NSEC_PER_SEC / setup->speed_freq;
/*
* Among Prescaler possibilities discovered above figures out SCL Low
* and High Period. Provided:
* - SCL Low Period has to be higher than SCL Clock Low Period
* defined by I2C Specification. I2C Clock has to be lower than
* (SCL Low Period - Analog/Digital filters) / 4.
* - SCL High Period has to be lower than SCL Clock High Period
* defined by I2C Specification
* - I2C Clock has to be lower than SCL High Period
*/
list_for_each_entry(v, &solutions, node) {
u32 prescaler = (v->presc + 1) * i2cclk;
for (l = 0; l < STM32F7_SCLL_MAX; l++) {
u32 tscl_l = (l + 1) * prescaler + tsync;
if ((tscl_l < specs->l_min) ||
(i2cclk >=
((tscl_l - af_delay_min - dnf_delay) / 4))) {
continue;
}
for (h = 0; h < STM32F7_SCLH_MAX; h++) {
u32 tscl_h = (h + 1) * prescaler + tsync;
u32 tscl = tscl_l + tscl_h +
setup->rise_time + setup->fall_time;
if ((tscl >= clk_min) && (tscl <= clk_max) &&
(tscl_h >= specs->h_min) &&
(i2cclk < tscl_h)) {
int clk_error = tscl - i2cbus;
if (clk_error < 0)
clk_error = -clk_error;
if (clk_error < clk_error_prev) {
clk_error_prev = clk_error;
v->scll = l;
v->sclh = h;
s = v;
}
}
}
}
}
if (!s) {
dev_err(i2c_dev->dev, "no solution at all\n");
ret = -EPERM;
goto exit;
}
output->presc = s->presc;
output->scldel = s->scldel;
output->sdadel = s->sdadel;
output->scll = s->scll;
output->sclh = s->sclh;
dev_dbg(i2c_dev->dev,
"Presc: %i, scldel: %i, sdadel: %i, scll: %i, sclh: %i\n",
output->presc,
output->scldel, output->sdadel,
output->scll, output->sclh);
exit:
/* Release list and memory */
list_for_each_entry_safe(v, _v, &solutions, node) {
list_del(&v->node);
kfree(v);
}
return ret;
}
static u32 stm32f7_get_lower_rate(u32 rate)
{
int i = ARRAY_SIZE(stm32f7_i2c_specs);
while (--i)
if (stm32f7_i2c_specs[i].rate < rate)
break;
return stm32f7_i2c_specs[i].rate;
}
static int stm32f7_i2c_setup_timing(struct stm32f7_i2c_dev *i2c_dev,
struct stm32f7_i2c_setup *setup)
{
struct i2c_timings timings, *t = &timings;
int ret = 0;
t->bus_freq_hz = I2C_MAX_STANDARD_MODE_FREQ;
t->scl_rise_ns = i2c_dev->setup.rise_time;
t->scl_fall_ns = i2c_dev->setup.fall_time;
i2c_parse_fw_timings(i2c_dev->dev, t, false);
if (t->bus_freq_hz > I2C_MAX_FAST_MODE_PLUS_FREQ) {
dev_err(i2c_dev->dev, "Invalid bus speed (%i>%i)\n",
t->bus_freq_hz, I2C_MAX_FAST_MODE_PLUS_FREQ);
return -EINVAL;
}
setup->speed_freq = t->bus_freq_hz;
i2c_dev->setup.rise_time = t->scl_rise_ns;
i2c_dev->setup.fall_time = t->scl_fall_ns;
i2c_dev->dnf_dt = t->digital_filter_width_ns;
setup->clock_src = clk_get_rate(i2c_dev->clk);
if (!setup->clock_src) {
dev_err(i2c_dev->dev, "clock rate is 0\n");
return -EINVAL;
}
if (!of_property_read_bool(i2c_dev->dev->of_node, "i2c-digital-filter"))
i2c_dev->dnf_dt = STM32F7_I2C_DNF_DEFAULT;
do {
ret = stm32f7_i2c_compute_timing(i2c_dev, setup,
&i2c_dev->timing);
if (ret) {
dev_err(i2c_dev->dev,
"failed to compute I2C timings.\n");
if (setup->speed_freq <= I2C_MAX_STANDARD_MODE_FREQ)
break;
setup->speed_freq =
stm32f7_get_lower_rate(setup->speed_freq);
dev_warn(i2c_dev->dev,
"downgrade I2C Speed Freq to (%i)\n",
setup->speed_freq);
}
} while (ret);
if (ret) {
dev_err(i2c_dev->dev, "Impossible to compute I2C timings.\n");
return ret;
}
i2c_dev->analog_filter = of_property_read_bool(i2c_dev->dev->of_node,
"i2c-analog-filter");
dev_dbg(i2c_dev->dev, "I2C Speed(%i), Clk Source(%i)\n",
setup->speed_freq, setup->clock_src);
dev_dbg(i2c_dev->dev, "I2C Rise(%i) and Fall(%i) Time\n",
setup->rise_time, setup->fall_time);
dev_dbg(i2c_dev->dev, "I2C Analog Filter(%s), DNF(%i)\n",
(i2c_dev->analog_filter ? "On" : "Off"), i2c_dev->dnf);
i2c_dev->bus_rate = setup->speed_freq;
return 0;
}
static void stm32f7_i2c_disable_dma_req(struct stm32f7_i2c_dev *i2c_dev)
{
void __iomem *base = i2c_dev->base;
u32 mask = STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN;
stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1, mask);
}
static void stm32f7_i2c_dma_callback(void *arg)
{
struct stm32f7_i2c_dev *i2c_dev = (struct stm32f7_i2c_dev *)arg;
struct stm32_i2c_dma *dma = i2c_dev->dma;
struct device *dev = dma->chan_using->device->dev;
stm32f7_i2c_disable_dma_req(i2c_dev);
dma_unmap_single(dev, dma->dma_buf, dma->dma_len, dma->dma_data_dir);
complete(&dma->dma_complete);
}
static void stm32f7_i2c_hw_config(struct stm32f7_i2c_dev *i2c_dev)
{
struct stm32f7_i2c_timings *t = &i2c_dev->timing;
u32 timing = 0;
/* Timing settings */
timing |= STM32F7_I2C_TIMINGR_PRESC(t->presc);
timing |= STM32F7_I2C_TIMINGR_SCLDEL(t->scldel);
timing |= STM32F7_I2C_TIMINGR_SDADEL(t->sdadel);
timing |= STM32F7_I2C_TIMINGR_SCLH(t->sclh);
timing |= STM32F7_I2C_TIMINGR_SCLL(t->scll);
writel_relaxed(timing, i2c_dev->base + STM32F7_I2C_TIMINGR);
/* Configure the Analog Filter */
if (i2c_dev->analog_filter)
stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1,
STM32F7_I2C_CR1_ANFOFF);
else
stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1,
STM32F7_I2C_CR1_ANFOFF);
/* Program the Digital Filter */
stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1,
STM32F7_I2C_CR1_DNF_MASK);
stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1,
STM32F7_I2C_CR1_DNF(i2c_dev->dnf));
stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1,
STM32F7_I2C_CR1_PE);
}
static void stm32f7_i2c_write_tx_data(struct stm32f7_i2c_dev *i2c_dev)
{
struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
void __iomem *base = i2c_dev->base;
if (f7_msg->count) {
writeb_relaxed(*f7_msg->buf++, base + STM32F7_I2C_TXDR);
f7_msg->count--;
}
}
static void stm32f7_i2c_read_rx_data(struct stm32f7_i2c_dev *i2c_dev)
{
struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
void __iomem *base = i2c_dev->base;
if (f7_msg->count) {
*f7_msg->buf++ = readb_relaxed(base + STM32F7_I2C_RXDR);
f7_msg->count--;
} else {
/* Flush RX buffer has no data is expected */
readb_relaxed(base + STM32F7_I2C_RXDR);
}
}
static void stm32f7_i2c_reload(struct stm32f7_i2c_dev *i2c_dev)
{
struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
u32 cr2;
if (i2c_dev->use_dma)
f7_msg->count -= STM32F7_I2C_MAX_LEN;
cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2);
cr2 &= ~STM32F7_I2C_CR2_NBYTES_MASK;
if (f7_msg->count > STM32F7_I2C_MAX_LEN) {
cr2 |= STM32F7_I2C_CR2_NBYTES(STM32F7_I2C_MAX_LEN);
} else {
cr2 &= ~STM32F7_I2C_CR2_RELOAD;
cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
}
writel_relaxed(cr2, i2c_dev->base + STM32F7_I2C_CR2);
}
static void stm32f7_i2c_smbus_reload(struct stm32f7_i2c_dev *i2c_dev)
{
struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
u32 cr2;
u8 *val;
/*
* For I2C_SMBUS_BLOCK_DATA && I2C_SMBUS_BLOCK_PROC_CALL, the first
* data received inform us how many data will follow.
*/
stm32f7_i2c_read_rx_data(i2c_dev);
/*
* Update NBYTES with the value read to continue the transfer
*/
val = f7_msg->buf - sizeof(u8);
f7_msg->count = *val;
cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2);
cr2 &= ~(STM32F7_I2C_CR2_NBYTES_MASK | STM32F7_I2C_CR2_RELOAD);
cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
writel_relaxed(cr2, i2c_dev->base + STM32F7_I2C_CR2);
}
static int stm32f7_i2c_release_bus(struct i2c_adapter *i2c_adap)
{
struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap);
dev_info(i2c_dev->dev, "Trying to recover bus\n");
stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1,
STM32F7_I2C_CR1_PE);
stm32f7_i2c_hw_config(i2c_dev);
return 0;
}
static int stm32f7_i2c_wait_free_bus(struct stm32f7_i2c_dev *i2c_dev)
{
u32 status;
int ret;
ret = readl_relaxed_poll_timeout(i2c_dev->base + STM32F7_I2C_ISR,
status,
!(status & STM32F7_I2C_ISR_BUSY),
10, 1000);
if (!ret)
return 0;
dev_info(i2c_dev->dev, "bus busy\n");
ret = stm32f7_i2c_release_bus(&i2c_dev->adap);
if (ret) {
dev_err(i2c_dev->dev, "Failed to recover the bus (%d)\n", ret);
return ret;
}
return -EBUSY;
}
static void stm32f7_i2c_xfer_msg(struct stm32f7_i2c_dev *i2c_dev,
struct i2c_msg *msg)
{
struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
void __iomem *base = i2c_dev->base;
u32 cr1, cr2;
int ret;
f7_msg->addr = msg->addr;
f7_msg->buf = msg->buf;
f7_msg->count = msg->len;
f7_msg->result = 0;
f7_msg->stop = (i2c_dev->msg_id >= i2c_dev->msg_num - 1);
reinit_completion(&i2c_dev->complete);
cr1 = readl_relaxed(base + STM32F7_I2C_CR1);
cr2 = readl_relaxed(base + STM32F7_I2C_CR2);
/* Set transfer direction */
cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
if (msg->flags & I2C_M_RD)
cr2 |= STM32F7_I2C_CR2_RD_WRN;
/* Set slave address */
cr2 &= ~(STM32F7_I2C_CR2_HEAD10R | STM32F7_I2C_CR2_ADD10);
if (msg->flags & I2C_M_TEN) {
cr2 &= ~STM32F7_I2C_CR2_SADD10_MASK;
cr2 |= STM32F7_I2C_CR2_SADD10(f7_msg->addr);
cr2 |= STM32F7_I2C_CR2_ADD10;
} else {
cr2 &= ~STM32F7_I2C_CR2_SADD7_MASK;
cr2 |= STM32F7_I2C_CR2_SADD7(f7_msg->addr);
}
/* Set nb bytes to transfer and reload if needed */
cr2 &= ~(STM32F7_I2C_CR2_NBYTES_MASK | STM32F7_I2C_CR2_RELOAD);
if (f7_msg->count > STM32F7_I2C_MAX_LEN) {
cr2 |= STM32F7_I2C_CR2_NBYTES(STM32F7_I2C_MAX_LEN);
cr2 |= STM32F7_I2C_CR2_RELOAD;
} else {
cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
}
/* Enable NACK, STOP, error and transfer complete interrupts */
cr1 |= STM32F7_I2C_CR1_ERRIE | STM32F7_I2C_CR1_TCIE |
STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE;
/* Clear DMA req and TX/RX interrupt */
cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE |
STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN);
/* Configure DMA or enable RX/TX interrupt */
i2c_dev->use_dma = false;
if (i2c_dev->dma && f7_msg->count >= STM32F7_I2C_DMA_LEN_MIN) {
ret = stm32_i2c_prep_dma_xfer(i2c_dev->dev, i2c_dev->dma,
msg->flags & I2C_M_RD,
f7_msg->count, f7_msg->buf,
stm32f7_i2c_dma_callback,
i2c_dev);
if (!ret)
i2c_dev->use_dma = true;
else
dev_warn(i2c_dev->dev, "can't use DMA\n");
}
if (!i2c_dev->use_dma) {
if (msg->flags & I2C_M_RD)
cr1 |= STM32F7_I2C_CR1_RXIE;
else
cr1 |= STM32F7_I2C_CR1_TXIE;
} else {
if (msg->flags & I2C_M_RD)
cr1 |= STM32F7_I2C_CR1_RXDMAEN;
else
cr1 |= STM32F7_I2C_CR1_TXDMAEN;
}
/* Configure Start/Repeated Start */
cr2 |= STM32F7_I2C_CR2_START;
i2c_dev->master_mode = true;
/* Write configurations registers */
writel_relaxed(cr1, base + STM32F7_I2C_CR1);
writel_relaxed(cr2, base + STM32F7_I2C_CR2);
}
static int stm32f7_i2c_smbus_xfer_msg(struct stm32f7_i2c_dev *i2c_dev,
unsigned short flags, u8 command,
union i2c_smbus_data *data)
{
struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
struct device *dev = i2c_dev->dev;
void __iomem *base = i2c_dev->base;
u32 cr1, cr2;
int i, ret;
f7_msg->result = 0;
reinit_completion(&i2c_dev->complete);
cr2 = readl_relaxed(base + STM32F7_I2C_CR2);
cr1 = readl_relaxed(base + STM32F7_I2C_CR1);
/* Set transfer direction */
cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
if (f7_msg->read_write)
cr2 |= STM32F7_I2C_CR2_RD_WRN;
/* Set slave address */
cr2 &= ~(STM32F7_I2C_CR2_ADD10 | STM32F7_I2C_CR2_SADD7_MASK);
cr2 |= STM32F7_I2C_CR2_SADD7(f7_msg->addr);
f7_msg->smbus_buf[0] = command;
switch (f7_msg->size) {
case I2C_SMBUS_QUICK:
f7_msg->stop = true;
f7_msg->count = 0;
break;
case I2C_SMBUS_BYTE:
f7_msg->stop = true;
f7_msg->count = 1;
break;
case I2C_SMBUS_BYTE_DATA:
if (f7_msg->read_write) {
f7_msg->stop = false;
f7_msg->count = 1;
cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
} else {
f7_msg->stop = true;
f7_msg->count = 2;
f7_msg->smbus_buf[1] = data->byte;
}
break;
case I2C_SMBUS_WORD_DATA:
if (f7_msg->read_write) {
f7_msg->stop = false;
f7_msg->count = 1;
cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
} else {
f7_msg->stop = true;
f7_msg->count = 3;
f7_msg->smbus_buf[1] = data->word & 0xff;
f7_msg->smbus_buf[2] = data->word >> 8;
}
break;
case I2C_SMBUS_BLOCK_DATA:
if (f7_msg->read_write) {
f7_msg->stop = false;
f7_msg->count = 1;
cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
} else {
f7_msg->stop = true;
if (data->block[0] > I2C_SMBUS_BLOCK_MAX ||
!data->block[0]) {
dev_err(dev, "Invalid block write size %d\n",
data->block[0]);
return -EINVAL;
}
f7_msg->count = data->block[0] + 2;
for (i = 1; i < f7_msg->count; i++)
f7_msg->smbus_buf[i] = data->block[i - 1];
}
break;
case I2C_SMBUS_PROC_CALL:
f7_msg->stop = false;
f7_msg->count = 3;
f7_msg->smbus_buf[1] = data->word & 0xff;
f7_msg->smbus_buf[2] = data->word >> 8;
cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
f7_msg->read_write = I2C_SMBUS_READ;
break;
case I2C_SMBUS_BLOCK_PROC_CALL:
f7_msg->stop = false;
if (data->block[0] > I2C_SMBUS_BLOCK_MAX - 1) {
dev_err(dev, "Invalid block write size %d\n",
data->block[0]);
return -EINVAL;
}
f7_msg->count = data->block[0] + 2;
for (i = 1; i < f7_msg->count; i++)
f7_msg->smbus_buf[i] = data->block[i - 1];
cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
f7_msg->read_write = I2C_SMBUS_READ;
break;
case I2C_SMBUS_I2C_BLOCK_DATA:
/* Rely on emulated i2c transfer (through master_xfer) */
return -EOPNOTSUPP;
default:
dev_err(dev, "Unsupported smbus protocol %d\n", f7_msg->size);
return -EOPNOTSUPP;
}
f7_msg->buf = f7_msg->smbus_buf;
/* Configure PEC */
if ((flags & I2C_CLIENT_PEC) && f7_msg->size != I2C_SMBUS_QUICK) {
cr1 |= STM32F7_I2C_CR1_PECEN;
cr2 |= STM32F7_I2C_CR2_PECBYTE;
if (!f7_msg->read_write)
f7_msg->count++;
} else {
cr1 &= ~STM32F7_I2C_CR1_PECEN;
cr2 &= ~STM32F7_I2C_CR2_PECBYTE;
}
/* Set number of bytes to be transferred */
cr2 &= ~(STM32F7_I2C_CR2_NBYTES_MASK | STM32F7_I2C_CR2_RELOAD);
cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
/* Enable NACK, STOP, error and transfer complete interrupts */
cr1 |= STM32F7_I2C_CR1_ERRIE | STM32F7_I2C_CR1_TCIE |
STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE;
/* Clear DMA req and TX/RX interrupt */
cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE |
STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN);
/* Configure DMA or enable RX/TX interrupt */
i2c_dev->use_dma = false;
if (i2c_dev->dma && f7_msg->count >= STM32F7_I2C_DMA_LEN_MIN) {
ret = stm32_i2c_prep_dma_xfer(i2c_dev->dev, i2c_dev->dma,
cr2 & STM32F7_I2C_CR2_RD_WRN,
f7_msg->count, f7_msg->buf,
stm32f7_i2c_dma_callback,
i2c_dev);
if (!ret)
i2c_dev->use_dma = true;
else
dev_warn(i2c_dev->dev, "can't use DMA\n");
}
if (!i2c_dev->use_dma) {
if (cr2 & STM32F7_I2C_CR2_RD_WRN)
cr1 |= STM32F7_I2C_CR1_RXIE;
else
cr1 |= STM32F7_I2C_CR1_TXIE;
} else {
if (cr2 & STM32F7_I2C_CR2_RD_WRN)
cr1 |= STM32F7_I2C_CR1_RXDMAEN;
else
cr1 |= STM32F7_I2C_CR1_TXDMAEN;
}
/* Set Start bit */
cr2 |= STM32F7_I2C_CR2_START;
i2c_dev->master_mode = true;
/* Write configurations registers */
writel_relaxed(cr1, base + STM32F7_I2C_CR1);
writel_relaxed(cr2, base + STM32F7_I2C_CR2);
return 0;
}
static void stm32f7_i2c_smbus_rep_start(struct stm32f7_i2c_dev *i2c_dev)
{
struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
void __iomem *base = i2c_dev->base;
u32 cr1, cr2;
int ret;
cr2 = readl_relaxed(base + STM32F7_I2C_CR2);
cr1 = readl_relaxed(base + STM32F7_I2C_CR1);
/* Set transfer direction */
cr2 |= STM32F7_I2C_CR2_RD_WRN;
switch (f7_msg->size) {
case I2C_SMBUS_BYTE_DATA:
f7_msg->count = 1;
break;
case I2C_SMBUS_WORD_DATA:
case I2C_SMBUS_PROC_CALL:
f7_msg->count = 2;
break;
case I2C_SMBUS_BLOCK_DATA:
case I2C_SMBUS_BLOCK_PROC_CALL:
f7_msg->count = 1;
cr2 |= STM32F7_I2C_CR2_RELOAD;
break;
}
f7_msg->buf = f7_msg->smbus_buf;
f7_msg->stop = true;
/* Add one byte for PEC if needed */
if (cr1 & STM32F7_I2C_CR1_PECEN)
f7_msg->count++;
/* Set number of bytes to be transferred */
cr2 &= ~(STM32F7_I2C_CR2_NBYTES_MASK);
cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
/*
* Configure RX/TX interrupt:
*/
cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE);
cr1 |= STM32F7_I2C_CR1_RXIE;
/*
* Configure DMA or enable RX/TX interrupt:
* For I2C_SMBUS_BLOCK_DATA and I2C_SMBUS_BLOCK_PROC_CALL we don't use
* dma as we don't know in advance how many data will be received
*/
cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE |
STM32F7_I2C_CR1_RXDMAEN | STM32F7_I2C_CR1_TXDMAEN);
i2c_dev->use_dma = false;
if (i2c_dev->dma && f7_msg->count >= STM32F7_I2C_DMA_LEN_MIN &&
f7_msg->size != I2C_SMBUS_BLOCK_DATA &&
f7_msg->size != I2C_SMBUS_BLOCK_PROC_CALL) {
ret = stm32_i2c_prep_dma_xfer(i2c_dev->dev, i2c_dev->dma,
cr2 & STM32F7_I2C_CR2_RD_WRN,
f7_msg->count, f7_msg->buf,
stm32f7_i2c_dma_callback,
i2c_dev);
if (!ret)
i2c_dev->use_dma = true;
else
dev_warn(i2c_dev->dev, "can't use DMA\n");
}
if (!i2c_dev->use_dma)
cr1 |= STM32F7_I2C_CR1_RXIE;
else
cr1 |= STM32F7_I2C_CR1_RXDMAEN;
/* Configure Repeated Start */
cr2 |= STM32F7_I2C_CR2_START;
/* Write configurations registers */
writel_relaxed(cr1, base + STM32F7_I2C_CR1);
writel_relaxed(cr2, base + STM32F7_I2C_CR2);
}
static int stm32f7_i2c_smbus_check_pec(struct stm32f7_i2c_dev *i2c_dev)
{
struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
u8 count, internal_pec, received_pec;
internal_pec = readl_relaxed(i2c_dev->base + STM32F7_I2C_PECR);
switch (f7_msg->size) {
case I2C_SMBUS_BYTE:
case I2C_SMBUS_BYTE_DATA:
received_pec = f7_msg->smbus_buf[1];
break;
case I2C_SMBUS_WORD_DATA:
case I2C_SMBUS_PROC_CALL:
received_pec = f7_msg->smbus_buf[2];
break;
case I2C_SMBUS_BLOCK_DATA:
case I2C_SMBUS_BLOCK_PROC_CALL:
count = f7_msg->smbus_buf[0];
received_pec = f7_msg->smbus_buf[count];
break;
default:
dev_err(i2c_dev->dev, "Unsupported smbus protocol for PEC\n");
return -EINVAL;
}
if (internal_pec != received_pec) {
dev_err(i2c_dev->dev, "Bad PEC 0x%02x vs. 0x%02x\n",
internal_pec, received_pec);
return -EBADMSG;
}
return 0;
}
static bool stm32f7_i2c_is_addr_match(struct i2c_client *slave, u32 addcode)
{
u32 addr;
if (!slave)
return false;
if (slave->flags & I2C_CLIENT_TEN) {
/*
* For 10-bit addr, addcode = 11110XY with
* X = Bit 9 of slave address
* Y = Bit 8 of slave address
*/
addr = slave->addr >> 8;
addr |= 0x78;
if (addr == addcode)
return true;
} else {
addr = slave->addr & 0x7f;
if (addr == addcode)
return true;
}
return false;
}
static void stm32f7_i2c_slave_start(struct stm32f7_i2c_dev *i2c_dev)
{
struct i2c_client *slave = i2c_dev->slave_running;
void __iomem *base = i2c_dev->base;
u32 mask;
u8 value = 0;
if (i2c_dev->slave_dir) {
/* Notify i2c slave that new read transfer is starting */
i2c_slave_event(slave, I2C_SLAVE_READ_REQUESTED, &value);
/*
* Disable slave TX config in case of I2C combined message
* (I2C Write followed by I2C Read)
*/
mask = STM32F7_I2C_CR2_RELOAD;
stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR2, mask);
mask = STM32F7_I2C_CR1_SBC | STM32F7_I2C_CR1_RXIE |
STM32F7_I2C_CR1_TCIE;
stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1, mask);
/* Enable TX empty, STOP, NACK interrupts */
mask = STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE |
STM32F7_I2C_CR1_TXIE;
stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask);
/* Write 1st data byte */
writel_relaxed(value, base + STM32F7_I2C_TXDR);
} else {
/* Notify i2c slave that new write transfer is starting */
i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value);
/* Set reload mode to be able to ACK/NACK each received byte */
mask = STM32F7_I2C_CR2_RELOAD;
stm32f7_i2c_set_bits(base + STM32F7_I2C_CR2, mask);
/*
* Set STOP, NACK, RX empty and transfer complete interrupts.*
* Set Slave Byte Control to be able to ACK/NACK each data
* byte received
*/
mask = STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE |
STM32F7_I2C_CR1_SBC | STM32F7_I2C_CR1_RXIE |
STM32F7_I2C_CR1_TCIE;
stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask);
}
}
static void stm32f7_i2c_slave_addr(struct stm32f7_i2c_dev *i2c_dev)
{
void __iomem *base = i2c_dev->base;
u32 isr, addcode, dir, mask;
int i;
isr = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
addcode = STM32F7_I2C_ISR_ADDCODE_GET(isr);
dir = isr & STM32F7_I2C_ISR_DIR;
for (i = 0; i < STM32F7_I2C_MAX_SLAVE; i++) {
if (stm32f7_i2c_is_addr_match(i2c_dev->slave[i], addcode)) {
i2c_dev->slave_running = i2c_dev->slave[i];
i2c_dev->slave_dir = dir;
/* Start I2C slave processing */
stm32f7_i2c_slave_start(i2c_dev);
/* Clear ADDR flag */
mask = STM32F7_I2C_ICR_ADDRCF;
writel_relaxed(mask, base + STM32F7_I2C_ICR);
break;
}
}
}
static int stm32f7_i2c_get_slave_id(struct stm32f7_i2c_dev *i2c_dev,
struct i2c_client *slave, int *id)
{
int i;
for (i = 0; i < STM32F7_I2C_MAX_SLAVE; i++) {
if (i2c_dev->slave[i] == slave) {
*id = i;
return 0;
}
}
dev_err(i2c_dev->dev, "Slave 0x%x not registered\n", slave->addr);
return -ENODEV;
}
static int stm32f7_i2c_get_free_slave_id(struct stm32f7_i2c_dev *i2c_dev,
struct i2c_client *slave, int *id)
{
struct device *dev = i2c_dev->dev;
int i;
/*
* slave[STM32F7_SLAVE_HOSTNOTIFY] support only SMBus Host address (0x8)
* slave[STM32F7_SLAVE_7_10_BITS_ADDR] supports 7-bit and 10-bit slave address
* slave[STM32F7_SLAVE_7_BITS_ADDR] supports 7-bit slave address only
*/
if (i2c_dev->smbus_mode && (slave->addr == 0x08)) {
if (i2c_dev->slave[STM32F7_SLAVE_HOSTNOTIFY])
goto fail;
*id = STM32F7_SLAVE_HOSTNOTIFY;
return 0;
}
for (i = STM32F7_I2C_MAX_SLAVE - 1; i > STM32F7_SLAVE_HOSTNOTIFY; i--) {
if ((i == STM32F7_SLAVE_7_BITS_ADDR) &&
(slave->flags & I2C_CLIENT_TEN))
continue;
if (!i2c_dev->slave[i]) {
*id = i;
return 0;
}
}
fail:
dev_err(dev, "Slave 0x%x could not be registered\n", slave->addr);
return -EINVAL;
}
static bool stm32f7_i2c_is_slave_registered(struct stm32f7_i2c_dev *i2c_dev)
{
int i;
for (i = 0; i < STM32F7_I2C_MAX_SLAVE; i++) {
if (i2c_dev->slave[i])
return true;
}
return false;
}
static bool stm32f7_i2c_is_slave_busy(struct stm32f7_i2c_dev *i2c_dev)
{
int i, busy;
busy = 0;
for (i = 0; i < STM32F7_I2C_MAX_SLAVE; i++) {
if (i2c_dev->slave[i])
busy++;
}
return i == busy;
}
static irqreturn_t stm32f7_i2c_slave_isr_event(struct stm32f7_i2c_dev *i2c_dev)
{
void __iomem *base = i2c_dev->base;
u32 cr2, status, mask;
u8 val;
int ret;
status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
/* Slave transmitter mode */
if (status & STM32F7_I2C_ISR_TXIS) {
i2c_slave_event(i2c_dev->slave_running,
I2C_SLAVE_READ_PROCESSED,
&val);
/* Write data byte */
writel_relaxed(val, base + STM32F7_I2C_TXDR);
}
/* Transfer Complete Reload for Slave receiver mode */
if (status & STM32F7_I2C_ISR_TCR || status & STM32F7_I2C_ISR_RXNE) {
/*
* Read data byte then set NBYTES to receive next byte or NACK
* the current received byte
*/
val = readb_relaxed(i2c_dev->base + STM32F7_I2C_RXDR);
ret = i2c_slave_event(i2c_dev->slave_running,
I2C_SLAVE_WRITE_RECEIVED,
&val);
if (!ret) {
cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2);
cr2 |= STM32F7_I2C_CR2_NBYTES(1);
writel_relaxed(cr2, i2c_dev->base + STM32F7_I2C_CR2);
} else {
mask = STM32F7_I2C_CR2_NACK;
stm32f7_i2c_set_bits(base + STM32F7_I2C_CR2, mask);
}
}
/* NACK received */
if (status & STM32F7_I2C_ISR_NACKF) {
dev_dbg(i2c_dev->dev, "<%s>: Receive NACK\n", __func__);
writel_relaxed(STM32F7_I2C_ICR_NACKCF, base + STM32F7_I2C_ICR);
}
/* STOP received */
if (status & STM32F7_I2C_ISR_STOPF) {
/* Disable interrupts */
stm32f7_i2c_disable_irq(i2c_dev, STM32F7_I2C_XFER_IRQ_MASK);
if (i2c_dev->slave_dir) {
/*
* Flush TX buffer in order to not used the byte in
* TXDR for the next transfer
*/
mask = STM32F7_I2C_ISR_TXE;
stm32f7_i2c_set_bits(base + STM32F7_I2C_ISR, mask);
}
/* Clear STOP flag */
writel_relaxed(STM32F7_I2C_ICR_STOPCF, base + STM32F7_I2C_ICR);
/* Notify i2c slave that a STOP flag has been detected */
i2c_slave_event(i2c_dev->slave_running, I2C_SLAVE_STOP, &val);
i2c_dev->slave_running = NULL;
}
/* Address match received */
if (status & STM32F7_I2C_ISR_ADDR)
stm32f7_i2c_slave_addr(i2c_dev);
return IRQ_HANDLED;
}
static irqreturn_t stm32f7_i2c_isr_event(int irq, void *data)
{
struct stm32f7_i2c_dev *i2c_dev = data;
struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
void __iomem *base = i2c_dev->base;
u32 status, mask;
int ret = IRQ_HANDLED;
/* Check if the interrupt if for a slave device */
if (!i2c_dev->master_mode) {
ret = stm32f7_i2c_slave_isr_event(i2c_dev);
return ret;
}
status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
/* Tx empty */
if (status & STM32F7_I2C_ISR_TXIS)
stm32f7_i2c_write_tx_data(i2c_dev);
/* RX not empty */
if (status & STM32F7_I2C_ISR_RXNE)
stm32f7_i2c_read_rx_data(i2c_dev);
/* NACK received */
if (status & STM32F7_I2C_ISR_NACKF) {
dev_dbg(i2c_dev->dev, "<%s>: Receive NACK (addr %x)\n",
__func__, f7_msg->addr);
writel_relaxed(STM32F7_I2C_ICR_NACKCF, base + STM32F7_I2C_ICR);
f7_msg->result = -ENXIO;
}
/* STOP detection flag */
if (status & STM32F7_I2C_ISR_STOPF) {
/* Disable interrupts */
if (stm32f7_i2c_is_slave_registered(i2c_dev))
mask = STM32F7_I2C_XFER_IRQ_MASK;
else
mask = STM32F7_I2C_ALL_IRQ_MASK;
stm32f7_i2c_disable_irq(i2c_dev, mask);
/* Clear STOP flag */
writel_relaxed(STM32F7_I2C_ICR_STOPCF, base + STM32F7_I2C_ICR);
if (i2c_dev->use_dma) {
ret = IRQ_WAKE_THREAD;
} else {
i2c_dev->master_mode = false;
complete(&i2c_dev->complete);
}
}
/* Transfer complete */
if (status & STM32F7_I2C_ISR_TC) {
if (f7_msg->stop) {
mask = STM32F7_I2C_CR2_STOP;
stm32f7_i2c_set_bits(base + STM32F7_I2C_CR2, mask);
} else if (i2c_dev->use_dma) {
ret = IRQ_WAKE_THREAD;
} else if (f7_msg->smbus) {
stm32f7_i2c_smbus_rep_start(i2c_dev);
} else {
i2c_dev->msg_id++;
i2c_dev->msg++;
stm32f7_i2c_xfer_msg(i2c_dev, i2c_dev->msg);
}
}
if (status & STM32F7_I2C_ISR_TCR) {
if (f7_msg->smbus)
stm32f7_i2c_smbus_reload(i2c_dev);
else
stm32f7_i2c_reload(i2c_dev);
}
return ret;
}
static irqreturn_t stm32f7_i2c_isr_event_thread(int irq, void *data)
{
struct stm32f7_i2c_dev *i2c_dev = data;
struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
struct stm32_i2c_dma *dma = i2c_dev->dma;
u32 status;
int ret;
/*
* Wait for dma transfer completion before sending next message or
* notity the end of xfer to the client
*/
ret = wait_for_completion_timeout(&i2c_dev->dma->dma_complete, HZ);
if (!ret) {
dev_dbg(i2c_dev->dev, "<%s>: Timed out\n", __func__);
stm32f7_i2c_disable_dma_req(i2c_dev);
dmaengine_terminate_all(dma->chan_using);
f7_msg->result = -ETIMEDOUT;
}
status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
if (status & STM32F7_I2C_ISR_TC) {
if (f7_msg->smbus) {
stm32f7_i2c_smbus_rep_start(i2c_dev);
} else {
i2c_dev->msg_id++;
i2c_dev->msg++;
stm32f7_i2c_xfer_msg(i2c_dev, i2c_dev->msg);
}
} else {
i2c_dev->master_mode = false;
complete(&i2c_dev->complete);
}
return IRQ_HANDLED;
}
static irqreturn_t stm32f7_i2c_isr_error(int irq, void *data)
{
struct stm32f7_i2c_dev *i2c_dev = data;
struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
void __iomem *base = i2c_dev->base;
struct device *dev = i2c_dev->dev;
struct stm32_i2c_dma *dma = i2c_dev->dma;
u32 status;
status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
/* Bus error */
if (status & STM32F7_I2C_ISR_BERR) {
dev_err(dev, "<%s>: Bus error accessing addr 0x%x\n",
__func__, f7_msg->addr);
writel_relaxed(STM32F7_I2C_ICR_BERRCF, base + STM32F7_I2C_ICR);
stm32f7_i2c_release_bus(&i2c_dev->adap);
f7_msg->result = -EIO;
}
/* Arbitration loss */
if (status & STM32F7_I2C_ISR_ARLO) {
dev_dbg(dev, "<%s>: Arbitration loss accessing addr 0x%x\n",
__func__, f7_msg->addr);
writel_relaxed(STM32F7_I2C_ICR_ARLOCF, base + STM32F7_I2C_ICR);
f7_msg->result = -EAGAIN;
}
if (status & STM32F7_I2C_ISR_PECERR) {
dev_err(dev, "<%s>: PEC error in reception accessing addr 0x%x\n",
__func__, f7_msg->addr);
writel_relaxed(STM32F7_I2C_ICR_PECCF, base + STM32F7_I2C_ICR);
f7_msg->result = -EINVAL;
}
if (status & STM32F7_I2C_ISR_ALERT) {
dev_dbg(dev, "<%s>: SMBus alert received\n", __func__);
writel_relaxed(STM32F7_I2C_ICR_ALERTCF, base + STM32F7_I2C_ICR);
i2c_handle_smbus_alert(i2c_dev->alert->ara);
return IRQ_HANDLED;
}
if (!i2c_dev->slave_running) {
u32 mask;
/* Disable interrupts */
if (stm32f7_i2c_is_slave_registered(i2c_dev))
mask = STM32F7_I2C_XFER_IRQ_MASK;
else
mask = STM32F7_I2C_ALL_IRQ_MASK;
stm32f7_i2c_disable_irq(i2c_dev, mask);
}
/* Disable dma */
if (i2c_dev->use_dma) {
stm32f7_i2c_disable_dma_req(i2c_dev);
dmaengine_terminate_all(dma->chan_using);
}
i2c_dev->master_mode = false;
complete(&i2c_dev->complete);
return IRQ_HANDLED;
}
static int stm32f7_i2c_xfer(struct i2c_adapter *i2c_adap,
struct i2c_msg msgs[], int num)
{
struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap);
struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
struct stm32_i2c_dma *dma = i2c_dev->dma;
unsigned long time_left;
int ret;
i2c_dev->msg = msgs;
i2c_dev->msg_num = num;
i2c_dev->msg_id = 0;
f7_msg->smbus = false;
ret = pm_runtime_resume_and_get(i2c_dev->dev);
if (ret < 0)
return ret;
ret = stm32f7_i2c_wait_free_bus(i2c_dev);
if (ret)
goto pm_free;
stm32f7_i2c_xfer_msg(i2c_dev, msgs);
time_left = wait_for_completion_timeout(&i2c_dev->complete,
i2c_dev->adap.timeout);
ret = f7_msg->result;
if (!time_left) {
dev_dbg(i2c_dev->dev, "Access to slave 0x%x timed out\n",
i2c_dev->msg->addr);
if (i2c_dev->use_dma)
dmaengine_terminate_all(dma->chan_using);
ret = -ETIMEDOUT;
}
pm_free:
pm_runtime_mark_last_busy(i2c_dev->dev);
pm_runtime_put_autosuspend(i2c_dev->dev);
return (ret < 0) ? ret : num;
}
static int stm32f7_i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
unsigned short flags, char read_write,
u8 command, int size,
union i2c_smbus_data *data)
{
struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(adapter);
struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
struct stm32_i2c_dma *dma = i2c_dev->dma;
struct device *dev = i2c_dev->dev;
unsigned long timeout;
int i, ret;
f7_msg->addr = addr;
f7_msg->size = size;
f7_msg->read_write = read_write;
f7_msg->smbus = true;
ret = pm_runtime_resume_and_get(dev);
if (ret < 0)
return ret;
ret = stm32f7_i2c_wait_free_bus(i2c_dev);
if (ret)
goto pm_free;
ret = stm32f7_i2c_smbus_xfer_msg(i2c_dev, flags, command, data);
if (ret)
goto pm_free;
timeout = wait_for_completion_timeout(&i2c_dev->complete,
i2c_dev->adap.timeout);
ret = f7_msg->result;
if (ret)
goto pm_free;
if (!timeout) {
dev_dbg(dev, "Access to slave 0x%x timed out\n", f7_msg->addr);
if (i2c_dev->use_dma)
dmaengine_terminate_all(dma->chan_using);
ret = -ETIMEDOUT;
goto pm_free;
}
/* Check PEC */
if ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK && read_write) {
ret = stm32f7_i2c_smbus_check_pec(i2c_dev);
if (ret)
goto pm_free;
}
if (read_write && size != I2C_SMBUS_QUICK) {
switch (size) {
case I2C_SMBUS_BYTE:
case I2C_SMBUS_BYTE_DATA:
data->byte = f7_msg->smbus_buf[0];
break;
case I2C_SMBUS_WORD_DATA:
case I2C_SMBUS_PROC_CALL:
data->word = f7_msg->smbus_buf[0] |
(f7_msg->smbus_buf[1] << 8);
break;
case I2C_SMBUS_BLOCK_DATA:
case I2C_SMBUS_BLOCK_PROC_CALL:
for (i = 0; i <= f7_msg->smbus_buf[0]; i++)
data->block[i] = f7_msg->smbus_buf[i];
break;
default:
dev_err(dev, "Unsupported smbus transaction\n");
ret = -EINVAL;
}
}
pm_free:
pm_runtime_mark_last_busy(dev);
pm_runtime_put_autosuspend(dev);
return ret;
}
static void stm32f7_i2c_enable_wakeup(struct stm32f7_i2c_dev *i2c_dev,
bool enable)
{
void __iomem *base = i2c_dev->base;
u32 mask = STM32F7_I2C_CR1_WUPEN;
if (!i2c_dev->wakeup_src)
return;
if (enable) {
device_set_wakeup_enable(i2c_dev->dev, true);
stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask);
} else {
device_set_wakeup_enable(i2c_dev->dev, false);
stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1, mask);
}
}
static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
{
struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(slave->adapter);
void __iomem *base = i2c_dev->base;
struct device *dev = i2c_dev->dev;
u32 oar1, oar2, mask;
int id, ret;
if (slave->flags & I2C_CLIENT_PEC) {
dev_err(dev, "SMBus PEC not supported in slave mode\n");
return -EINVAL;
}
if (stm32f7_i2c_is_slave_busy(i2c_dev)) {
dev_err(dev, "Too much slave registered\n");
return -EBUSY;
}
ret = stm32f7_i2c_get_free_slave_id(i2c_dev, slave, &id);
if (ret)
return ret;
ret = pm_runtime_resume_and_get(dev);
if (ret < 0)
return ret;
if (!stm32f7_i2c_is_slave_registered(i2c_dev))
stm32f7_i2c_enable_wakeup(i2c_dev, true);
switch (id) {
case 0:
/* Slave SMBus Host */
i2c_dev->slave[id] = slave;
break;
case 1:
/* Configure Own Address 1 */
oar1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR1);
oar1 &= ~STM32F7_I2C_OAR1_MASK;
if (slave->flags & I2C_CLIENT_TEN) {
oar1 |= STM32F7_I2C_OAR1_OA1_10(slave->addr);
oar1 |= STM32F7_I2C_OAR1_OA1MODE;
} else {
oar1 |= STM32F7_I2C_OAR1_OA1_7(slave->addr);
}
oar1 |= STM32F7_I2C_OAR1_OA1EN;
i2c_dev->slave[id] = slave;
writel_relaxed(oar1, i2c_dev->base + STM32F7_I2C_OAR1);
break;
case 2:
/* Configure Own Address 2 */
oar2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR2);
oar2 &= ~STM32F7_I2C_OAR2_MASK;
if (slave->flags & I2C_CLIENT_TEN) {
ret = -EOPNOTSUPP;
goto pm_free;
}
oar2 |= STM32F7_I2C_OAR2_OA2_7(slave->addr);
oar2 |= STM32F7_I2C_OAR2_OA2EN;
i2c_dev->slave[id] = slave;
writel_relaxed(oar2, i2c_dev->base + STM32F7_I2C_OAR2);
break;
default:
dev_err(dev, "I2C slave id not supported\n");
ret = -ENODEV;
goto pm_free;
}
/* Enable ACK */
stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR2, STM32F7_I2C_CR2_NACK);
/* Enable Address match interrupt, error interrupt and enable I2C */
mask = STM32F7_I2C_CR1_ADDRIE | STM32F7_I2C_CR1_ERRIE |
STM32F7_I2C_CR1_PE;
stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask);
ret = 0;
pm_free:
if (!stm32f7_i2c_is_slave_registered(i2c_dev))
stm32f7_i2c_enable_wakeup(i2c_dev, false);
pm_runtime_mark_last_busy(dev);
pm_runtime_put_autosuspend(dev);
return ret;
}
static int stm32f7_i2c_unreg_slave(struct i2c_client *slave)
{
struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(slave->adapter);
void __iomem *base = i2c_dev->base;
u32 mask;
int id, ret;
ret = stm32f7_i2c_get_slave_id(i2c_dev, slave, &id);
if (ret)
return ret;
WARN_ON(!i2c_dev->slave[id]);
ret = pm_runtime_resume_and_get(i2c_dev->dev);
if (ret < 0)
return ret;
if (id == 1) {
mask = STM32F7_I2C_OAR1_OA1EN;
stm32f7_i2c_clr_bits(base + STM32F7_I2C_OAR1, mask);
} else if (id == 2) {
mask = STM32F7_I2C_OAR2_OA2EN;
stm32f7_i2c_clr_bits(base + STM32F7_I2C_OAR2, mask);
}
i2c_dev->slave[id] = NULL;
if (!stm32f7_i2c_is_slave_registered(i2c_dev)) {
stm32f7_i2c_disable_irq(i2c_dev, STM32F7_I2C_ALL_IRQ_MASK);
stm32f7_i2c_enable_wakeup(i2c_dev, false);
}
pm_runtime_mark_last_busy(i2c_dev->dev);
pm_runtime_put_autosuspend(i2c_dev->dev);
return 0;
}
static int stm32f7_i2c_write_fm_plus_bits(struct stm32f7_i2c_dev *i2c_dev,
bool enable)
{
int ret;
if (i2c_dev->bus_rate <= I2C_MAX_FAST_MODE_FREQ ||
IS_ERR_OR_NULL(i2c_dev->regmap))
/* Optional */
return 0;
if (i2c_dev->fmp_sreg == i2c_dev->fmp_creg)
ret = regmap_update_bits(i2c_dev->regmap,
i2c_dev->fmp_sreg,
i2c_dev->fmp_mask,
enable ? i2c_dev->fmp_mask : 0);
else
ret = regmap_write(i2c_dev->regmap,
enable ? i2c_dev->fmp_sreg :
i2c_dev->fmp_creg,
i2c_dev->fmp_mask);
return ret;
}
static int stm32f7_i2c_setup_fm_plus_bits(struct platform_device *pdev,
struct stm32f7_i2c_dev *i2c_dev)
{
struct device_node *np = pdev->dev.of_node;
int ret;
i2c_dev->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg-fmp");
if (IS_ERR(i2c_dev->regmap))
/* Optional */
return 0;
ret = of_property_read_u32_index(np, "st,syscfg-fmp", 1,
&i2c_dev->fmp_sreg);
if (ret)
return ret;
i2c_dev->fmp_creg = i2c_dev->fmp_sreg +
i2c_dev->setup.fmp_clr_offset;
return of_property_read_u32_index(np, "st,syscfg-fmp", 2,
&i2c_dev->fmp_mask);
}
static int stm32f7_i2c_enable_smbus_host(struct stm32f7_i2c_dev *i2c_dev)
{
struct i2c_adapter *adap = &i2c_dev->adap;
void __iomem *base = i2c_dev->base;
struct i2c_client *client;
client = i2c_new_slave_host_notify_device(adap);
if (IS_ERR(client))
return PTR_ERR(client);
i2c_dev->host_notify_client = client;
/* Enable SMBus Host address */
stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, STM32F7_I2C_CR1_SMBHEN);
return 0;
}
static void stm32f7_i2c_disable_smbus_host(struct stm32f7_i2c_dev *i2c_dev)
{
void __iomem *base = i2c_dev->base;
if (i2c_dev->host_notify_client) {
/* Disable SMBus Host address */
stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1,
STM32F7_I2C_CR1_SMBHEN);
i2c_free_slave_host_notify_device(i2c_dev->host_notify_client);
}
}
static int stm32f7_i2c_enable_smbus_alert(struct stm32f7_i2c_dev *i2c_dev)
{
struct stm32f7_i2c_alert *alert;
struct i2c_adapter *adap = &i2c_dev->adap;
struct device *dev = i2c_dev->dev;
void __iomem *base = i2c_dev->base;
alert = devm_kzalloc(dev, sizeof(*alert), GFP_KERNEL);
if (!alert)
return -ENOMEM;
alert->ara = i2c_new_smbus_alert_device(adap, &alert->setup);
if (IS_ERR(alert->ara))
return PTR_ERR(alert->ara);
i2c_dev->alert = alert;
/* Enable SMBus Alert */
stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, STM32F7_I2C_CR1_ALERTEN);
return 0;
}
static void stm32f7_i2c_disable_smbus_alert(struct stm32f7_i2c_dev *i2c_dev)
{
struct stm32f7_i2c_alert *alert = i2c_dev->alert;
void __iomem *base = i2c_dev->base;
if (alert) {
/* Disable SMBus Alert */
stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1,
STM32F7_I2C_CR1_ALERTEN);
i2c_unregister_device(alert->ara);
}
}
static u32 stm32f7_i2c_func(struct i2c_adapter *adap)
{
struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
u32 func = I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SLAVE |
I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_PEC |
I2C_FUNC_SMBUS_I2C_BLOCK;
if (i2c_dev->smbus_mode)
func |= I2C_FUNC_SMBUS_HOST_NOTIFY;
return func;
}
static const struct i2c_algorithm stm32f7_i2c_algo = {
.master_xfer = stm32f7_i2c_xfer,
.smbus_xfer = stm32f7_i2c_smbus_xfer,
.functionality = stm32f7_i2c_func,
.reg_slave = stm32f7_i2c_reg_slave,
.unreg_slave = stm32f7_i2c_unreg_slave,
};
static int stm32f7_i2c_probe(struct platform_device *pdev)
{
struct stm32f7_i2c_dev *i2c_dev;
const struct stm32f7_i2c_setup *setup;
struct resource *res;
struct i2c_adapter *adap;
struct reset_control *rst;
dma_addr_t phy_addr;
int irq_error, irq_event, ret;
i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
if (!i2c_dev)
return -ENOMEM;
i2c_dev->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
if (IS_ERR(i2c_dev->base))
return PTR_ERR(i2c_dev->base);
phy_addr = (dma_addr_t)res->start;
irq_event = platform_get_irq(pdev, 0);
if (irq_event <= 0)
return irq_event ? : -ENOENT;
irq_error = platform_get_irq(pdev, 1);
if (irq_error <= 0)
return irq_error ? : -ENOENT;
i2c_dev->wakeup_src = of_property_read_bool(pdev->dev.of_node,
"wakeup-source");
i2c_dev->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(i2c_dev->clk))
return dev_err_probe(&pdev->dev, PTR_ERR(i2c_dev->clk),
"Failed to get controller clock\n");
ret = clk_prepare_enable(i2c_dev->clk);
if (ret) {
dev_err(&pdev->dev, "Failed to prepare_enable clock\n");
return ret;
}
rst = devm_reset_control_get(&pdev->dev, NULL);
if (IS_ERR(rst)) {
ret = dev_err_probe(&pdev->dev, PTR_ERR(rst),
"Error: Missing reset ctrl\n");
goto clk_free;
}
reset_control_assert(rst);
udelay(2);
reset_control_deassert(rst);
i2c_dev->dev = &pdev->dev;
ret = devm_request_threaded_irq(&pdev->dev, irq_event,
stm32f7_i2c_isr_event,
stm32f7_i2c_isr_event_thread,
IRQF_ONESHOT,
pdev->name, i2c_dev);
if (ret) {
dev_err(&pdev->dev, "Failed to request irq event %i\n",
irq_event);
goto clk_free;
}
ret = devm_request_irq(&pdev->dev, irq_error, stm32f7_i2c_isr_error, 0,
pdev->name, i2c_dev);
if (ret) {
dev_err(&pdev->dev, "Failed to request irq error %i\n",
irq_error);
goto clk_free;
}
setup = of_device_get_match_data(&pdev->dev);
if (!setup) {
dev_err(&pdev->dev, "Can't get device data\n");
ret = -ENODEV;
goto clk_free;
}
i2c_dev->setup = *setup;
ret = stm32f7_i2c_setup_timing(i2c_dev, &i2c_dev->setup);
if (ret)
goto clk_free;
/* Setup Fast mode plus if necessary */
if (i2c_dev->bus_rate > I2C_MAX_FAST_MODE_FREQ) {
ret = stm32f7_i2c_setup_fm_plus_bits(pdev, i2c_dev);
if (ret)
goto clk_free;
ret = stm32f7_i2c_write_fm_plus_bits(i2c_dev, true);
if (ret)
goto clk_free;
}
adap = &i2c_dev->adap;
i2c_set_adapdata(adap, i2c_dev);
snprintf(adap->name, sizeof(adap->name), "STM32F7 I2C(%pa)",
&res->start);
adap->owner = THIS_MODULE;
adap->timeout = 2 * HZ;
adap->retries = 3;
adap->algo = &stm32f7_i2c_algo;
adap->dev.parent = &pdev->dev;
adap->dev.of_node = pdev->dev.of_node;
init_completion(&i2c_dev->complete);
/* Init DMA config if supported */
i2c_dev->dma = stm32_i2c_dma_request(i2c_dev->dev, phy_addr,
STM32F7_I2C_TXDR,
STM32F7_I2C_RXDR);
if (IS_ERR(i2c_dev->dma)) {
ret = PTR_ERR(i2c_dev->dma);
/* DMA support is optional, only report other errors */
if (ret != -ENODEV)
goto fmp_clear;
dev_dbg(i2c_dev->dev, "No DMA option: fallback using interrupts\n");
i2c_dev->dma = NULL;
}
if (i2c_dev->wakeup_src) {
device_set_wakeup_capable(i2c_dev->dev, true);
ret = dev_pm_set_wake_irq(i2c_dev->dev, irq_event);
if (ret) {
dev_err(i2c_dev->dev, "Failed to set wake up irq\n");
goto clr_wakeup_capable;
}
}
platform_set_drvdata(pdev, i2c_dev);
pm_runtime_set_autosuspend_delay(i2c_dev->dev,
STM32F7_AUTOSUSPEND_DELAY);
pm_runtime_use_autosuspend(i2c_dev->dev);
pm_runtime_set_active(i2c_dev->dev);
pm_runtime_enable(i2c_dev->dev);
pm_runtime_get_noresume(&pdev->dev);
stm32f7_i2c_hw_config(i2c_dev);
i2c_dev->smbus_mode = of_property_read_bool(pdev->dev.of_node, "smbus");
ret = i2c_add_adapter(adap);
if (ret)
goto pm_disable;
if (i2c_dev->smbus_mode) {
ret = stm32f7_i2c_enable_smbus_host(i2c_dev);
if (ret) {
dev_err(i2c_dev->dev,
"failed to enable SMBus Host-Notify protocol (%d)\n",
ret);
goto i2c_adapter_remove;
}
}
if (of_property_read_bool(pdev->dev.of_node, "smbus-alert")) {
ret = stm32f7_i2c_enable_smbus_alert(i2c_dev);
if (ret) {
dev_err(i2c_dev->dev,
"failed to enable SMBus alert protocol (%d)\n",
ret);
goto i2c_disable_smbus_host;
}
}
dev_info(i2c_dev->dev, "STM32F7 I2C-%d bus adapter\n", adap->nr);
pm_runtime_mark_last_busy(i2c_dev->dev);
pm_runtime_put_autosuspend(i2c_dev->dev);
return 0;
i2c_disable_smbus_host:
stm32f7_i2c_disable_smbus_host(i2c_dev);
i2c_adapter_remove:
i2c_del_adapter(adap);
pm_disable:
pm_runtime_put_noidle(i2c_dev->dev);
pm_runtime_disable(i2c_dev->dev);
pm_runtime_set_suspended(i2c_dev->dev);
pm_runtime_dont_use_autosuspend(i2c_dev->dev);
if (i2c_dev->wakeup_src)
dev_pm_clear_wake_irq(i2c_dev->dev);
clr_wakeup_capable:
if (i2c_dev->wakeup_src)
device_set_wakeup_capable(i2c_dev->dev, false);
if (i2c_dev->dma) {
stm32_i2c_dma_free(i2c_dev->dma);
i2c_dev->dma = NULL;
}
fmp_clear:
stm32f7_i2c_write_fm_plus_bits(i2c_dev, false);
clk_free:
clk_disable_unprepare(i2c_dev->clk);
return ret;
}
static int stm32f7_i2c_remove(struct platform_device *pdev)
{
struct stm32f7_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
stm32f7_i2c_disable_smbus_alert(i2c_dev);
stm32f7_i2c_disable_smbus_host(i2c_dev);
i2c_del_adapter(&i2c_dev->adap);
pm_runtime_get_sync(i2c_dev->dev);
if (i2c_dev->wakeup_src) {
dev_pm_clear_wake_irq(i2c_dev->dev);
/*
* enforce that wakeup is disabled and that the device
* is marked as non wakeup capable
*/
device_init_wakeup(i2c_dev->dev, false);
}
pm_runtime_put_noidle(i2c_dev->dev);
pm_runtime_disable(i2c_dev->dev);
pm_runtime_set_suspended(i2c_dev->dev);
pm_runtime_dont_use_autosuspend(i2c_dev->dev);
if (i2c_dev->dma) {
stm32_i2c_dma_free(i2c_dev->dma);
i2c_dev->dma = NULL;
}
stm32f7_i2c_write_fm_plus_bits(i2c_dev, false);
clk_disable_unprepare(i2c_dev->clk);
return 0;
}
static int __maybe_unused stm32f7_i2c_runtime_suspend(struct device *dev)
{
struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev);
if (!stm32f7_i2c_is_slave_registered(i2c_dev))
clk_disable_unprepare(i2c_dev->clk);
return 0;
}
static int __maybe_unused stm32f7_i2c_runtime_resume(struct device *dev)
{
struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev);
int ret;
if (!stm32f7_i2c_is_slave_registered(i2c_dev)) {
ret = clk_prepare_enable(i2c_dev->clk);
if (ret) {
dev_err(dev, "failed to prepare_enable clock\n");
return ret;
}
}
return 0;
}
static int __maybe_unused stm32f7_i2c_regs_backup(struct stm32f7_i2c_dev *i2c_dev)
{
int ret;
struct stm32f7_i2c_regs *backup_regs = &i2c_dev->backup_regs;
ret = pm_runtime_resume_and_get(i2c_dev->dev);
if (ret < 0)
return ret;
backup_regs->cr1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR1);
backup_regs->cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2);
backup_regs->oar1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR1);
backup_regs->oar2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR2);
backup_regs->tmgr = readl_relaxed(i2c_dev->base + STM32F7_I2C_TIMINGR);
stm32f7_i2c_write_fm_plus_bits(i2c_dev, false);
pm_runtime_put_sync(i2c_dev->dev);
return ret;
}
static int __maybe_unused stm32f7_i2c_regs_restore(struct stm32f7_i2c_dev *i2c_dev)
{
u32 cr1;
int ret;
struct stm32f7_i2c_regs *backup_regs = &i2c_dev->backup_regs;
ret = pm_runtime_resume_and_get(i2c_dev->dev);
if (ret < 0)
return ret;
cr1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR1);
if (cr1 & STM32F7_I2C_CR1_PE)
stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1,
STM32F7_I2C_CR1_PE);
writel_relaxed(backup_regs->tmgr, i2c_dev->base + STM32F7_I2C_TIMINGR);
writel_relaxed(backup_regs->cr1 & ~STM32F7_I2C_CR1_PE,
i2c_dev->base + STM32F7_I2C_CR1);
if (backup_regs->cr1 & STM32F7_I2C_CR1_PE)
stm32f7_i2c_set_bits(i2c_dev->base + STM32F7_I2C_CR1,
STM32F7_I2C_CR1_PE);
writel_relaxed(backup_regs->cr2, i2c_dev->base + STM32F7_I2C_CR2);
writel_relaxed(backup_regs->oar1, i2c_dev->base + STM32F7_I2C_OAR1);
writel_relaxed(backup_regs->oar2, i2c_dev->base + STM32F7_I2C_OAR2);
stm32f7_i2c_write_fm_plus_bits(i2c_dev, true);
pm_runtime_put_sync(i2c_dev->dev);
return ret;
}
static int __maybe_unused stm32f7_i2c_suspend(struct device *dev)
{
struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev);
int ret;
i2c_mark_adapter_suspended(&i2c_dev->adap);
if (!device_may_wakeup(dev) && !device_wakeup_path(dev)) {
ret = stm32f7_i2c_regs_backup(i2c_dev);
if (ret < 0) {
i2c_mark_adapter_resumed(&i2c_dev->adap);
return ret;
}
pinctrl_pm_select_sleep_state(dev);
pm_runtime_force_suspend(dev);
}
return 0;
}
static int __maybe_unused stm32f7_i2c_resume(struct device *dev)
{
struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev);
int ret;
if (!device_may_wakeup(dev) && !device_wakeup_path(dev)) {
ret = pm_runtime_force_resume(dev);
if (ret < 0)
return ret;
pinctrl_pm_select_default_state(dev);
ret = stm32f7_i2c_regs_restore(i2c_dev);
if (ret < 0)
return ret;
}
i2c_mark_adapter_resumed(&i2c_dev->adap);
return 0;
}
static const struct dev_pm_ops stm32f7_i2c_pm_ops = {
SET_RUNTIME_PM_OPS(stm32f7_i2c_runtime_suspend,
stm32f7_i2c_runtime_resume, NULL)
SET_SYSTEM_SLEEP_PM_OPS(stm32f7_i2c_suspend, stm32f7_i2c_resume)
};
static const struct of_device_id stm32f7_i2c_match[] = {
{ .compatible = "st,stm32f7-i2c", .data = &stm32f7_setup},
{ .compatible = "st,stm32mp15-i2c", .data = &stm32mp15_setup},
{},
};
MODULE_DEVICE_TABLE(of, stm32f7_i2c_match);
static struct platform_driver stm32f7_i2c_driver = {
.driver = {
.name = "stm32f7-i2c",
.of_match_table = stm32f7_i2c_match,
.pm = &stm32f7_i2c_pm_ops,
},
.probe = stm32f7_i2c_probe,
.remove = stm32f7_i2c_remove,
};
module_platform_driver(stm32f7_i2c_driver);
MODULE_AUTHOR("M'boumba Cedric Madianga <cedric.madianga@gmail.com>");
MODULE_DESCRIPTION("STMicroelectronics STM32F7 I2C driver");
MODULE_LICENSE("GPL v2");
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