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linux-next/drivers/i2c/busses/i2c-tegra.c
Dmitry Osipenko 53fd42ff6c i2c: tegra: Improve driver module description 
Use proper spelling of "NVIDIA" and don't designate driver as Tegra2-only
since newer SoC generations are supported as well.

Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
2020-10-05 22:57:45 +02:00

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// SPDX-License-Identifier: GPL-2.0
/*
* drivers/i2c/busses/i2c-tegra.c
*
* Copyright (C) 2010 Google, Inc.
* Author: Colin Cross <ccross@android.com>
*/
#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/ktime.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/reset.h>
#define BYTES_PER_FIFO_WORD 4
#define I2C_CNFG 0x000
#define I2C_CNFG_DEBOUNCE_CNT GENMASK(14, 12)
#define I2C_CNFG_PACKET_MODE_EN BIT(10)
#define I2C_CNFG_NEW_MASTER_FSM BIT(11)
#define I2C_CNFG_MULTI_MASTER_MODE BIT(17)
#define I2C_STATUS 0x01c
#define I2C_SL_CNFG 0x020
#define I2C_SL_CNFG_NACK BIT(1)
#define I2C_SL_CNFG_NEWSL BIT(2)
#define I2C_SL_ADDR1 0x02c
#define I2C_SL_ADDR2 0x030
#define I2C_TLOW_SEXT 0x034
#define I2C_TX_FIFO 0x050
#define I2C_RX_FIFO 0x054
#define I2C_PACKET_TRANSFER_STATUS 0x058
#define I2C_FIFO_CONTROL 0x05c
#define I2C_FIFO_CONTROL_TX_FLUSH BIT(1)
#define I2C_FIFO_CONTROL_RX_FLUSH BIT(0)
#define I2C_FIFO_CONTROL_TX_TRIG(x) (((x) - 1) << 5)
#define I2C_FIFO_CONTROL_RX_TRIG(x) (((x) - 1) << 2)
#define I2C_FIFO_STATUS 0x060
#define I2C_FIFO_STATUS_TX GENMASK(7, 4)
#define I2C_FIFO_STATUS_RX GENMASK(3, 0)
#define I2C_INT_MASK 0x064
#define I2C_INT_STATUS 0x068
#define I2C_INT_BUS_CLR_DONE BIT(11)
#define I2C_INT_PACKET_XFER_COMPLETE BIT(7)
#define I2C_INT_NO_ACK BIT(3)
#define I2C_INT_ARBITRATION_LOST BIT(2)
#define I2C_INT_TX_FIFO_DATA_REQ BIT(1)
#define I2C_INT_RX_FIFO_DATA_REQ BIT(0)
#define I2C_CLK_DIVISOR 0x06c
#define I2C_CLK_DIVISOR_STD_FAST_MODE GENMASK(31, 16)
#define I2C_CLK_DIVISOR_HSMODE GENMASK(15, 0)
#define DVC_CTRL_REG1 0x000
#define DVC_CTRL_REG1_INTR_EN BIT(10)
#define DVC_CTRL_REG3 0x008
#define DVC_CTRL_REG3_SW_PROG BIT(26)
#define DVC_CTRL_REG3_I2C_DONE_INTR_EN BIT(30)
#define DVC_STATUS 0x00c
#define DVC_STATUS_I2C_DONE_INTR BIT(30)
#define I2C_ERR_NONE 0x00
#define I2C_ERR_NO_ACK BIT(0)
#define I2C_ERR_ARBITRATION_LOST BIT(1)
#define I2C_ERR_UNKNOWN_INTERRUPT BIT(2)
#define I2C_ERR_RX_BUFFER_OVERFLOW BIT(3)
#define PACKET_HEADER0_HEADER_SIZE GENMASK(29, 28)
#define PACKET_HEADER0_PACKET_ID GENMASK(23, 16)
#define PACKET_HEADER0_CONT_ID GENMASK(15, 12)
#define PACKET_HEADER0_PROTOCOL GENMASK(7, 4)
#define PACKET_HEADER0_PROTOCOL_I2C 1
#define I2C_HEADER_CONT_ON_NAK BIT(21)
#define I2C_HEADER_READ BIT(19)
#define I2C_HEADER_10BIT_ADDR BIT(18)
#define I2C_HEADER_IE_ENABLE BIT(17)
#define I2C_HEADER_REPEAT_START BIT(16)
#define I2C_HEADER_CONTINUE_XFER BIT(15)
#define I2C_HEADER_SLAVE_ADDR_SHIFT 1
#define I2C_BUS_CLEAR_CNFG 0x084
#define I2C_BC_SCLK_THRESHOLD GENMASK(23, 16)
#define I2C_BC_STOP_COND BIT(2)
#define I2C_BC_TERMINATE BIT(1)
#define I2C_BC_ENABLE BIT(0)
#define I2C_BUS_CLEAR_STATUS 0x088
#define I2C_BC_STATUS BIT(0)
#define I2C_CONFIG_LOAD 0x08c
#define I2C_MSTR_CONFIG_LOAD BIT(0)
#define I2C_CLKEN_OVERRIDE 0x090
#define I2C_MST_CORE_CLKEN_OVR BIT(0)
#define I2C_INTERFACE_TIMING_0 0x094
#define I2C_INTERFACE_TIMING_THIGH GENMASK(13, 8)
#define I2C_INTERFACE_TIMING_TLOW GENMASK(5, 0)
#define I2C_INTERFACE_TIMING_1 0x098
#define I2C_INTERFACE_TIMING_TBUF GENMASK(29, 24)
#define I2C_INTERFACE_TIMING_TSU_STO GENMASK(21, 16)
#define I2C_INTERFACE_TIMING_THD_STA GENMASK(13, 8)
#define I2C_INTERFACE_TIMING_TSU_STA GENMASK(5, 0)
#define I2C_HS_INTERFACE_TIMING_0 0x09c
#define I2C_HS_INTERFACE_TIMING_THIGH GENMASK(13, 8)
#define I2C_HS_INTERFACE_TIMING_TLOW GENMASK(5, 0)
#define I2C_HS_INTERFACE_TIMING_1 0x0a0
#define I2C_HS_INTERFACE_TIMING_TSU_STO GENMASK(21, 16)
#define I2C_HS_INTERFACE_TIMING_THD_STA GENMASK(13, 8)
#define I2C_HS_INTERFACE_TIMING_TSU_STA GENMASK(5, 0)
#define I2C_MST_FIFO_CONTROL 0x0b4
#define I2C_MST_FIFO_CONTROL_RX_FLUSH BIT(0)
#define I2C_MST_FIFO_CONTROL_TX_FLUSH BIT(1)
#define I2C_MST_FIFO_CONTROL_RX_TRIG(x) (((x) - 1) << 4)
#define I2C_MST_FIFO_CONTROL_TX_TRIG(x) (((x) - 1) << 16)
#define I2C_MST_FIFO_STATUS 0x0b8
#define I2C_MST_FIFO_STATUS_TX GENMASK(23, 16)
#define I2C_MST_FIFO_STATUS_RX GENMASK(7, 0)
/* configuration load timeout in microseconds */
#define I2C_CONFIG_LOAD_TIMEOUT 1000000
/* packet header size in bytes */
#define I2C_PACKET_HEADER_SIZE 12
/*
* I2C Controller will use PIO mode for transfers up to 32 bytes in order to
* avoid DMA overhead, otherwise external APB DMA controller will be used.
* Note that the actual MAX PIO length is 20 bytes because 32 bytes include
* I2C_PACKET_HEADER_SIZE.
*/
#define I2C_PIO_MODE_PREFERRED_LEN 32
/*
* msg_end_type: The bus control which needs to be sent at end of transfer.
* @MSG_END_STOP: Send stop pulse.
* @MSG_END_REPEAT_START: Send repeat-start.
* @MSG_END_CONTINUE: Don't send stop or repeat-start.
*/
enum msg_end_type {
MSG_END_STOP,
MSG_END_REPEAT_START,
MSG_END_CONTINUE,
};
/**
* struct tegra_i2c_hw_feature : per hardware generation features
* @has_continue_xfer_support: continue-transfer supported
* @has_per_pkt_xfer_complete_irq: Has enable/disable capability for transfer
* completion interrupt on per packet basis.
* @has_config_load_reg: Has the config load register to load the new
* configuration.
* @clk_divisor_hs_mode: Clock divisor in HS mode.
* @clk_divisor_std_mode: Clock divisor in standard mode. It is
* applicable if there is no fast clock source i.e. single clock
* source.
* @clk_divisor_fast_mode: Clock divisor in fast mode. It is
* applicable if there is no fast clock source i.e. single clock
* source.
* @clk_divisor_fast_plus_mode: Clock divisor in fast mode plus. It is
* applicable if there is no fast clock source (i.e. single
* clock source).
* @has_multi_master_mode: The I2C controller supports running in single-master
* or multi-master mode.
* @has_slcg_override_reg: The I2C controller supports a register that
* overrides the second level clock gating.
* @has_mst_fifo: The I2C controller contains the new MST FIFO interface that
* provides additional features and allows for longer messages to
* be transferred in one go.
* @quirks: I2C adapter quirks for limiting write/read transfer size and not
* allowing 0 length transfers.
* @supports_bus_clear: Bus Clear support to recover from bus hang during
* SDA stuck low from device for some unknown reasons.
* @has_apb_dma: Support of APBDMA on corresponding Tegra chip.
* @tlow_std_mode: Low period of the clock in standard mode.
* @thigh_std_mode: High period of the clock in standard mode.
* @tlow_fast_fastplus_mode: Low period of the clock in fast/fast-plus modes.
* @thigh_fast_fastplus_mode: High period of the clock in fast/fast-plus modes.
* @setup_hold_time_std_mode: Setup and hold time for start and stop conditions
* in standard mode.
* @setup_hold_time_fast_fast_plus_mode: Setup and hold time for start and stop
* conditions in fast/fast-plus modes.
* @setup_hold_time_hs_mode: Setup and hold time for start and stop conditions
* in HS mode.
* @has_interface_timing_reg: Has interface timing register to program the tuned
* timing settings.
*/
struct tegra_i2c_hw_feature {
bool has_continue_xfer_support;
bool has_per_pkt_xfer_complete_irq;
bool has_config_load_reg;
u32 clk_divisor_hs_mode;
u32 clk_divisor_std_mode;
u32 clk_divisor_fast_mode;
u32 clk_divisor_fast_plus_mode;
bool has_multi_master_mode;
bool has_slcg_override_reg;
bool has_mst_fifo;
const struct i2c_adapter_quirks *quirks;
bool supports_bus_clear;
bool has_apb_dma;
u32 tlow_std_mode;
u32 thigh_std_mode;
u32 tlow_fast_fastplus_mode;
u32 thigh_fast_fastplus_mode;
u32 setup_hold_time_std_mode;
u32 setup_hold_time_fast_fast_plus_mode;
u32 setup_hold_time_hs_mode;
bool has_interface_timing_reg;
};
/**
* struct tegra_i2c_dev - per device I2C context
* @dev: device reference for power management
* @hw: Tegra I2C HW feature
* @adapter: core I2C layer adapter information
* @div_clk: clock reference for div clock of I2C controller
* @clocks: array of I2C controller clocks
* @nclocks: number of clocks in the array
* @rst: reset control for the I2C controller
* @base: ioremapped registers cookie
* @base_phys: physical base address of the I2C controller
* @cont_id: I2C controller ID, used for packet header
* @irq: IRQ number of transfer complete interrupt
* @is_dvc: identifies the DVC I2C controller, has a different register layout
* @is_vi: identifies the VI I2C controller, has a different register layout
* @msg_complete: transfer completion notifier
* @msg_err: error code for completed message
* @msg_buf: pointer to current message data
* @msg_buf_remaining: size of unsent data in the message buffer
* @msg_read: indicates that the transfer is a read access
* @bus_clk_rate: current I2C bus clock rate
* @multimaster_mode: indicates that I2C controller is in multi-master mode
* @tx_dma_chan: DMA transmit channel
* @rx_dma_chan: DMA receive channel
* @dma_phys: handle to DMA resources
* @dma_buf: pointer to allocated DMA buffer
* @dma_buf_size: DMA buffer size
* @dma_mode: indicates active DMA transfer
* @dma_complete: DMA completion notifier
* @atomic_mode: indicates active atomic transfer
*/
struct tegra_i2c_dev {
struct device *dev;
struct i2c_adapter adapter;
const struct tegra_i2c_hw_feature *hw;
struct reset_control *rst;
unsigned int cont_id;
unsigned int irq;
phys_addr_t base_phys;
void __iomem *base;
struct clk_bulk_data clocks[2];
unsigned int nclocks;
struct clk *div_clk;
u32 bus_clk_rate;
struct completion msg_complete;
size_t msg_buf_remaining;
int msg_err;
u8 *msg_buf;
struct completion dma_complete;
struct dma_chan *tx_dma_chan;
struct dma_chan *rx_dma_chan;
unsigned int dma_buf_size;
dma_addr_t dma_phys;
void *dma_buf;
bool multimaster_mode;
bool atomic_mode;
bool dma_mode;
bool msg_read;
bool is_dvc;
bool is_vi;
};
static void dvc_writel(struct tegra_i2c_dev *i2c_dev, u32 val,
unsigned int reg)
{
writel_relaxed(val, i2c_dev->base + reg);
}
static u32 dvc_readl(struct tegra_i2c_dev *i2c_dev, unsigned int reg)
{
return readl_relaxed(i2c_dev->base + reg);
}
/*
* If necessary, i2c_writel() and i2c_readl() will offset the register
* in order to talk to the I2C block inside the DVC block.
*/
static u32 tegra_i2c_reg_addr(struct tegra_i2c_dev *i2c_dev, unsigned int reg)
{
if (i2c_dev->is_dvc)
reg += (reg >= I2C_TX_FIFO) ? 0x10 : 0x40;
else if (i2c_dev->is_vi)
reg = 0xc00 + (reg << 2);
return reg;
}
static void i2c_writel(struct tegra_i2c_dev *i2c_dev, u32 val, unsigned int reg)
{
writel_relaxed(val, i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
/* read back register to make sure that register writes completed */
if (reg != I2C_TX_FIFO)
readl_relaxed(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
}
static u32 i2c_readl(struct tegra_i2c_dev *i2c_dev, unsigned int reg)
{
return readl_relaxed(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
}
static void i2c_writesl(struct tegra_i2c_dev *i2c_dev, void *data,
unsigned int reg, unsigned int len)
{
writesl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
}
static void i2c_readsl(struct tegra_i2c_dev *i2c_dev, void *data,
unsigned int reg, unsigned int len)
{
readsl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
}
static void tegra_i2c_mask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask)
{
u32 int_mask;
int_mask = i2c_readl(i2c_dev, I2C_INT_MASK) & ~mask;
i2c_writel(i2c_dev, int_mask, I2C_INT_MASK);
}
static void tegra_i2c_unmask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask)
{
u32 int_mask;
int_mask = i2c_readl(i2c_dev, I2C_INT_MASK) | mask;
i2c_writel(i2c_dev, int_mask, I2C_INT_MASK);
}
static void tegra_i2c_dma_complete(void *args)
{
struct tegra_i2c_dev *i2c_dev = args;
complete(&i2c_dev->dma_complete);
}
static int tegra_i2c_dma_submit(struct tegra_i2c_dev *i2c_dev, size_t len)
{
struct dma_async_tx_descriptor *dma_desc;
enum dma_transfer_direction dir;
struct dma_chan *chan;
dev_dbg(i2c_dev->dev, "starting DMA for length: %zu\n", len);
reinit_completion(&i2c_dev->dma_complete);
dir = i2c_dev->msg_read ? DMA_DEV_TO_MEM : DMA_MEM_TO_DEV;
chan = i2c_dev->msg_read ? i2c_dev->rx_dma_chan : i2c_dev->tx_dma_chan;
dma_desc = dmaengine_prep_slave_single(chan, i2c_dev->dma_phys,
len, dir, DMA_PREP_INTERRUPT |
DMA_CTRL_ACK);
if (!dma_desc) {
dev_err(i2c_dev->dev, "failed to get %s DMA descriptor\n",
i2c_dev->msg_read ? "RX" : "TX");
return -EINVAL;
}
dma_desc->callback = tegra_i2c_dma_complete;
dma_desc->callback_param = i2c_dev;
dmaengine_submit(dma_desc);
dma_async_issue_pending(chan);
return 0;
}
static void tegra_i2c_release_dma(struct tegra_i2c_dev *i2c_dev)
{
if (i2c_dev->dma_buf) {
dma_free_coherent(i2c_dev->dev, i2c_dev->dma_buf_size,
i2c_dev->dma_buf, i2c_dev->dma_phys);
i2c_dev->dma_buf = NULL;
}
if (i2c_dev->tx_dma_chan) {
dma_release_channel(i2c_dev->tx_dma_chan);
i2c_dev->tx_dma_chan = NULL;
}
if (i2c_dev->rx_dma_chan) {
dma_release_channel(i2c_dev->rx_dma_chan);
i2c_dev->rx_dma_chan = NULL;
}
}
static int tegra_i2c_init_dma(struct tegra_i2c_dev *i2c_dev)
{
struct dma_chan *chan;
dma_addr_t dma_phys;
u32 *dma_buf;
int err;
if (!i2c_dev->hw->has_apb_dma || i2c_dev->is_vi)
return 0;
if (!IS_ENABLED(CONFIG_TEGRA20_APB_DMA)) {
dev_dbg(i2c_dev->dev, "DMA support not enabled\n");
return 0;
}
chan = dma_request_chan(i2c_dev->dev, "rx");
if (IS_ERR(chan)) {
err = PTR_ERR(chan);
goto err_out;
}
i2c_dev->rx_dma_chan = chan;
chan = dma_request_chan(i2c_dev->dev, "tx");
if (IS_ERR(chan)) {
err = PTR_ERR(chan);
goto err_out;
}
i2c_dev->tx_dma_chan = chan;
i2c_dev->dma_buf_size = i2c_dev->hw->quirks->max_write_len +
I2C_PACKET_HEADER_SIZE;
dma_buf = dma_alloc_coherent(i2c_dev->dev, i2c_dev->dma_buf_size,
&dma_phys, GFP_KERNEL | __GFP_NOWARN);
if (!dma_buf) {
dev_err(i2c_dev->dev, "failed to allocate DMA buffer\n");
err = -ENOMEM;
goto err_out;
}
i2c_dev->dma_buf = dma_buf;
i2c_dev->dma_phys = dma_phys;
return 0;
err_out:
tegra_i2c_release_dma(i2c_dev);
if (err != -EPROBE_DEFER) {
dev_err(i2c_dev->dev, "cannot use DMA: %d\n", err);
dev_err(i2c_dev->dev, "falling back to PIO\n");
return 0;
}
return err;
}
/*
* One of the Tegra I2C blocks is inside the DVC (Digital Voltage Controller)
* block. This block is identical to the rest of the I2C blocks, except that
* it only supports master mode, it has registers moved around, and it needs
* some extra init to get it into I2C mode. The register moves are handled
* by i2c_readl() and i2c_writel().
*/
static void tegra_dvc_init(struct tegra_i2c_dev *i2c_dev)
{
u32 val;
val = dvc_readl(i2c_dev, DVC_CTRL_REG3);
val |= DVC_CTRL_REG3_SW_PROG;
val |= DVC_CTRL_REG3_I2C_DONE_INTR_EN;
dvc_writel(i2c_dev, val, DVC_CTRL_REG3);
val = dvc_readl(i2c_dev, DVC_CTRL_REG1);
val |= DVC_CTRL_REG1_INTR_EN;
dvc_writel(i2c_dev, val, DVC_CTRL_REG1);
}
static void tegra_i2c_vi_init(struct tegra_i2c_dev *i2c_dev)
{
u32 value;
value = FIELD_PREP(I2C_INTERFACE_TIMING_THIGH, 2) |
FIELD_PREP(I2C_INTERFACE_TIMING_TLOW, 4);
i2c_writel(i2c_dev, value, I2C_INTERFACE_TIMING_0);
value = FIELD_PREP(I2C_INTERFACE_TIMING_TBUF, 4) |
FIELD_PREP(I2C_INTERFACE_TIMING_TSU_STO, 7) |
FIELD_PREP(I2C_INTERFACE_TIMING_THD_STA, 4) |
FIELD_PREP(I2C_INTERFACE_TIMING_TSU_STA, 4);
i2c_writel(i2c_dev, value, I2C_INTERFACE_TIMING_1);
value = FIELD_PREP(I2C_HS_INTERFACE_TIMING_THIGH, 3) |
FIELD_PREP(I2C_HS_INTERFACE_TIMING_TLOW, 8);
i2c_writel(i2c_dev, value, I2C_HS_INTERFACE_TIMING_0);
value = FIELD_PREP(I2C_HS_INTERFACE_TIMING_TSU_STO, 11) |
FIELD_PREP(I2C_HS_INTERFACE_TIMING_THD_STA, 11) |
FIELD_PREP(I2C_HS_INTERFACE_TIMING_TSU_STA, 11);
i2c_writel(i2c_dev, value, I2C_HS_INTERFACE_TIMING_1);
value = FIELD_PREP(I2C_BC_SCLK_THRESHOLD, 9) | I2C_BC_STOP_COND;
i2c_writel(i2c_dev, value, I2C_BUS_CLEAR_CNFG);
i2c_writel(i2c_dev, 0x0, I2C_TLOW_SEXT);
}
static int tegra_i2c_poll_register(struct tegra_i2c_dev *i2c_dev,
u32 reg, u32 mask, u32 delay_us,
u32 timeout_us)
{
void __iomem *addr = i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg);
u32 val;
if (!i2c_dev->atomic_mode)
return readl_relaxed_poll_timeout(addr, val, !(val & mask),
delay_us, timeout_us);
return readl_relaxed_poll_timeout_atomic(addr, val, !(val & mask),
delay_us, timeout_us);
}
static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev)
{
u32 mask, val, offset;
int err;
if (i2c_dev->hw->has_mst_fifo) {
mask = I2C_MST_FIFO_CONTROL_TX_FLUSH |
I2C_MST_FIFO_CONTROL_RX_FLUSH;
offset = I2C_MST_FIFO_CONTROL;
} else {
mask = I2C_FIFO_CONTROL_TX_FLUSH |
I2C_FIFO_CONTROL_RX_FLUSH;
offset = I2C_FIFO_CONTROL;
}
val = i2c_readl(i2c_dev, offset);
val |= mask;
i2c_writel(i2c_dev, val, offset);
err = tegra_i2c_poll_register(i2c_dev, offset, mask, 1000, 1000000);
if (err) {
dev_err(i2c_dev->dev, "failed to flush FIFO\n");
return err;
}
return 0;
}
static int tegra_i2c_wait_for_config_load(struct tegra_i2c_dev *i2c_dev)
{
int err;
if (!i2c_dev->hw->has_config_load_reg)
return 0;
i2c_writel(i2c_dev, I2C_MSTR_CONFIG_LOAD, I2C_CONFIG_LOAD);
err = tegra_i2c_poll_register(i2c_dev, I2C_CONFIG_LOAD, 0xffffffff,
1000, I2C_CONFIG_LOAD_TIMEOUT);
if (err) {
dev_err(i2c_dev->dev, "failed to load config\n");
return err;
}
return 0;
}
static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
{
u32 val, clk_divisor, clk_multiplier, tsu_thd, tlow, thigh, non_hs_mode;
int err;
/*
* The reset shouldn't ever fail in practice. The failure will be a
* sign of a severe problem that needs to be resolved. Still we don't
* want to fail the initialization completely because this may break
* kernel boot up since voltage regulators use I2C. Hence, we will
* emit a noisy warning on error, which won't stay unnoticed and
* won't hose machine entirely.
*/
err = reset_control_reset(i2c_dev->rst);
WARN_ON_ONCE(err);
if (i2c_dev->is_dvc)
tegra_dvc_init(i2c_dev);
val = I2C_CNFG_NEW_MASTER_FSM | I2C_CNFG_PACKET_MODE_EN |
FIELD_PREP(I2C_CNFG_DEBOUNCE_CNT, 2);
if (i2c_dev->hw->has_multi_master_mode)
val |= I2C_CNFG_MULTI_MASTER_MODE;
i2c_writel(i2c_dev, val, I2C_CNFG);
i2c_writel(i2c_dev, 0, I2C_INT_MASK);
if (i2c_dev->is_vi)
tegra_i2c_vi_init(i2c_dev);
switch (i2c_dev->bus_clk_rate) {
case I2C_MAX_STANDARD_MODE_FREQ + 1 ... I2C_MAX_FAST_MODE_PLUS_FREQ:
default:
tlow = i2c_dev->hw->tlow_fast_fastplus_mode;
thigh = i2c_dev->hw->thigh_fast_fastplus_mode;
tsu_thd = i2c_dev->hw->setup_hold_time_fast_fast_plus_mode;
if (i2c_dev->bus_clk_rate > I2C_MAX_FAST_MODE_FREQ)
non_hs_mode = i2c_dev->hw->clk_divisor_fast_plus_mode;
else
non_hs_mode = i2c_dev->hw->clk_divisor_fast_mode;
break;
case 0 ... I2C_MAX_STANDARD_MODE_FREQ:
tlow = i2c_dev->hw->tlow_std_mode;
thigh = i2c_dev->hw->thigh_std_mode;
tsu_thd = i2c_dev->hw->setup_hold_time_std_mode;
non_hs_mode = i2c_dev->hw->clk_divisor_std_mode;
break;
}
/* make sure clock divisor programmed correctly */
clk_divisor = FIELD_PREP(I2C_CLK_DIVISOR_HSMODE,
i2c_dev->hw->clk_divisor_hs_mode) |
FIELD_PREP(I2C_CLK_DIVISOR_STD_FAST_MODE, non_hs_mode);
i2c_writel(i2c_dev, clk_divisor, I2C_CLK_DIVISOR);
if (i2c_dev->hw->has_interface_timing_reg) {
val = FIELD_PREP(I2C_INTERFACE_TIMING_THIGH, thigh) |
FIELD_PREP(I2C_INTERFACE_TIMING_TLOW, tlow);
i2c_writel(i2c_dev, val, I2C_INTERFACE_TIMING_0);
}
/*
* Configure setup and hold times only when tsu_thd is non-zero.
* Otherwise, preserve the chip default values.
*/
if (i2c_dev->hw->has_interface_timing_reg && tsu_thd)
i2c_writel(i2c_dev, tsu_thd, I2C_INTERFACE_TIMING_1);
clk_multiplier = (tlow + thigh + 2) * (non_hs_mode + 1);
err = clk_set_rate(i2c_dev->div_clk,
i2c_dev->bus_clk_rate * clk_multiplier);
if (err) {
dev_err(i2c_dev->dev, "failed to set div-clk rate: %d\n", err);
return err;
}
if (!i2c_dev->is_dvc && !i2c_dev->is_vi) {
u32 sl_cfg = i2c_readl(i2c_dev, I2C_SL_CNFG);
sl_cfg |= I2C_SL_CNFG_NACK | I2C_SL_CNFG_NEWSL;
i2c_writel(i2c_dev, sl_cfg, I2C_SL_CNFG);
i2c_writel(i2c_dev, 0xfc, I2C_SL_ADDR1);
i2c_writel(i2c_dev, 0x00, I2C_SL_ADDR2);
}
err = tegra_i2c_flush_fifos(i2c_dev);
if (err)
return err;
if (i2c_dev->multimaster_mode && i2c_dev->hw->has_slcg_override_reg)
i2c_writel(i2c_dev, I2C_MST_CORE_CLKEN_OVR, I2C_CLKEN_OVERRIDE);
err = tegra_i2c_wait_for_config_load(i2c_dev);
if (err)
return err;
return 0;
}
static int tegra_i2c_disable_packet_mode(struct tegra_i2c_dev *i2c_dev)
{
u32 cnfg;
/*
* NACK interrupt is generated before the I2C controller generates
* the STOP condition on the bus. So, wait for 2 clock periods
* before disabling the controller so that the STOP condition has
* been delivered properly.
*/
udelay(DIV_ROUND_UP(2 * 1000000, i2c_dev->bus_clk_rate));
cnfg = i2c_readl(i2c_dev, I2C_CNFG);
if (cnfg & I2C_CNFG_PACKET_MODE_EN)
i2c_writel(i2c_dev, cnfg & ~I2C_CNFG_PACKET_MODE_EN, I2C_CNFG);
return tegra_i2c_wait_for_config_load(i2c_dev);
}
static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
{
size_t buf_remaining = i2c_dev->msg_buf_remaining;
unsigned int words_to_transfer, rx_fifo_avail;
u8 *buf = i2c_dev->msg_buf;
u32 val;
/*
* Catch overflow due to message fully sent before the check for
* RX FIFO availability.
*/
if (WARN_ON_ONCE(!(i2c_dev->msg_buf_remaining)))
return -EINVAL;
if (i2c_dev->hw->has_mst_fifo) {
val = i2c_readl(i2c_dev, I2C_MST_FIFO_STATUS);
rx_fifo_avail = FIELD_GET(I2C_MST_FIFO_STATUS_RX, val);
} else {
val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
rx_fifo_avail = FIELD_GET(I2C_FIFO_STATUS_RX, val);
}
/* round down to exclude partial word at the end of buffer */
words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
if (words_to_transfer > rx_fifo_avail)
words_to_transfer = rx_fifo_avail;
i2c_readsl(i2c_dev, buf, I2C_RX_FIFO, words_to_transfer);
buf += words_to_transfer * BYTES_PER_FIFO_WORD;
buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
rx_fifo_avail -= words_to_transfer;
/*
* If there is a partial word at the end of buffer, handle it
* manually to prevent overwriting past the end of buffer.
*/
if (rx_fifo_avail > 0 && buf_remaining > 0) {
/*
* buf_remaining > 3 check not needed as rx_fifo_avail == 0
* when (words_to_transfer was > rx_fifo_avail) earlier
* in this function.
*/
val = i2c_readl(i2c_dev, I2C_RX_FIFO);
val = cpu_to_le32(val);
memcpy(buf, &val, buf_remaining);
buf_remaining = 0;
rx_fifo_avail--;
}
/* RX FIFO must be drained, otherwise it's an Overflow case. */
if (WARN_ON_ONCE(rx_fifo_avail))
return -EINVAL;
i2c_dev->msg_buf_remaining = buf_remaining;
i2c_dev->msg_buf = buf;
return 0;
}
static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev)
{
size_t buf_remaining = i2c_dev->msg_buf_remaining;
unsigned int words_to_transfer, tx_fifo_avail;
u8 *buf = i2c_dev->msg_buf;
u32 val;
if (i2c_dev->hw->has_mst_fifo) {
val = i2c_readl(i2c_dev, I2C_MST_FIFO_STATUS);
tx_fifo_avail = FIELD_GET(I2C_MST_FIFO_STATUS_TX, val);
} else {
val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
tx_fifo_avail = FIELD_GET(I2C_FIFO_STATUS_TX, val);
}
/* round down to exclude partial word at the end of buffer */
words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
/*
* This hunk pushes 4 bytes at a time into the TX FIFO.
*
* It's very common to have < 4 bytes, hence there is no word
* to push if we have less than 4 bytes to transfer.
*/
if (words_to_transfer) {
if (words_to_transfer > tx_fifo_avail)
words_to_transfer = tx_fifo_avail;
/*
* Update state before writing to FIFO. Note that this may
* cause us to finish writing all bytes (AKA buf_remaining
* goes to 0), hence we have a potential for an interrupt
* (PACKET_XFER_COMPLETE is not maskable), but GIC interrupt
* is disabled at this point.
*/
buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
tx_fifo_avail -= words_to_transfer;
i2c_dev->msg_buf_remaining = buf_remaining;
i2c_dev->msg_buf = buf + words_to_transfer * BYTES_PER_FIFO_WORD;
i2c_writesl(i2c_dev, buf, I2C_TX_FIFO, words_to_transfer);
buf += words_to_transfer * BYTES_PER_FIFO_WORD;
}
/*
* If there is a partial word at the end of buffer, handle it manually
* to prevent reading past the end of buffer, which could cross a page
* boundary and fault.
*/
if (tx_fifo_avail > 0 && buf_remaining > 0) {
/*
* buf_remaining > 3 check not needed as tx_fifo_avail == 0
* when (words_to_transfer was > tx_fifo_avail) earlier
* in this function for non-zero words_to_transfer.
*/
memcpy(&val, buf, buf_remaining);
val = le32_to_cpu(val);
i2c_dev->msg_buf_remaining = 0;
i2c_dev->msg_buf = NULL;
i2c_writel(i2c_dev, val, I2C_TX_FIFO);
}
return 0;
}
static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
{
const u32 status_err = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
struct tegra_i2c_dev *i2c_dev = dev_id;
u32 status;
status = i2c_readl(i2c_dev, I2C_INT_STATUS);
if (status == 0) {
dev_warn(i2c_dev->dev, "IRQ status 0 %08x %08x %08x\n",
i2c_readl(i2c_dev, I2C_PACKET_TRANSFER_STATUS),
i2c_readl(i2c_dev, I2C_STATUS),
i2c_readl(i2c_dev, I2C_CNFG));
i2c_dev->msg_err |= I2C_ERR_UNKNOWN_INTERRUPT;
goto err;
}
if (status & status_err) {
tegra_i2c_disable_packet_mode(i2c_dev);
if (status & I2C_INT_NO_ACK)
i2c_dev->msg_err |= I2C_ERR_NO_ACK;
if (status & I2C_INT_ARBITRATION_LOST)
i2c_dev->msg_err |= I2C_ERR_ARBITRATION_LOST;
goto err;
}
/*
* I2C transfer is terminated during the bus clear, so skip
* processing the other interrupts.
*/
if (i2c_dev->hw->supports_bus_clear && (status & I2C_INT_BUS_CLR_DONE))
goto err;
if (!i2c_dev->dma_mode) {
if (i2c_dev->msg_read && (status & I2C_INT_RX_FIFO_DATA_REQ)) {
if (tegra_i2c_empty_rx_fifo(i2c_dev)) {
/*
* Overflow error condition: message fully sent,
* with no XFER_COMPLETE interrupt but hardware
* asks to transfer more.
*/
i2c_dev->msg_err |= I2C_ERR_RX_BUFFER_OVERFLOW;
goto err;
}
}
if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
if (i2c_dev->msg_buf_remaining)
tegra_i2c_fill_tx_fifo(i2c_dev);
else
tegra_i2c_mask_irq(i2c_dev,
I2C_INT_TX_FIFO_DATA_REQ);
}
}
i2c_writel(i2c_dev, status, I2C_INT_STATUS);
if (i2c_dev->is_dvc)
dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS);
/*
* During message read XFER_COMPLETE interrupt is triggered prior to
* DMA completion and during message write XFER_COMPLETE interrupt is
* triggered after DMA completion.
*
* PACKETS_XFER_COMPLETE indicates completion of all bytes of transfer,
* so forcing msg_buf_remaining to 0 in DMA mode.
*/
if (status & I2C_INT_PACKET_XFER_COMPLETE) {
if (i2c_dev->dma_mode)
i2c_dev->msg_buf_remaining = 0;
/*
* Underflow error condition: XFER_COMPLETE before message
* fully sent.
*/
if (WARN_ON_ONCE(i2c_dev->msg_buf_remaining)) {
i2c_dev->msg_err |= I2C_ERR_UNKNOWN_INTERRUPT;
goto err;
}
complete(&i2c_dev->msg_complete);
}
goto done;
err:
/* mask all interrupts on error */
tegra_i2c_mask_irq(i2c_dev,
I2C_INT_NO_ACK |
I2C_INT_ARBITRATION_LOST |
I2C_INT_PACKET_XFER_COMPLETE |
I2C_INT_TX_FIFO_DATA_REQ |
I2C_INT_RX_FIFO_DATA_REQ);
if (i2c_dev->hw->supports_bus_clear)
tegra_i2c_mask_irq(i2c_dev, I2C_INT_BUS_CLR_DONE);
i2c_writel(i2c_dev, status, I2C_INT_STATUS);
if (i2c_dev->is_dvc)
dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS);
if (i2c_dev->dma_mode) {
if (i2c_dev->msg_read)
dmaengine_terminate_async(i2c_dev->rx_dma_chan);
else
dmaengine_terminate_async(i2c_dev->tx_dma_chan);
complete(&i2c_dev->dma_complete);
}
complete(&i2c_dev->msg_complete);
done:
return IRQ_HANDLED;
}
static void tegra_i2c_config_fifo_trig(struct tegra_i2c_dev *i2c_dev,
size_t len)
{
struct dma_slave_config slv_config = {0};
u32 val, reg, dma_burst, reg_offset;
struct dma_chan *chan;
int err;
if (i2c_dev->hw->has_mst_fifo)
reg = I2C_MST_FIFO_CONTROL;
else
reg = I2C_FIFO_CONTROL;
if (i2c_dev->dma_mode) {
if (len & 0xF)
dma_burst = 1;
else if (len & 0x10)
dma_burst = 4;
else
dma_burst = 8;
if (i2c_dev->msg_read) {
chan = i2c_dev->rx_dma_chan;
reg_offset = tegra_i2c_reg_addr(i2c_dev, I2C_RX_FIFO);
slv_config.src_addr = i2c_dev->base_phys + reg_offset;
slv_config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
slv_config.src_maxburst = dma_burst;
if (i2c_dev->hw->has_mst_fifo)
val = I2C_MST_FIFO_CONTROL_RX_TRIG(dma_burst);
else
val = I2C_FIFO_CONTROL_RX_TRIG(dma_burst);
} else {
chan = i2c_dev->tx_dma_chan;
reg_offset = tegra_i2c_reg_addr(i2c_dev, I2C_TX_FIFO);
slv_config.dst_addr = i2c_dev->base_phys + reg_offset;
slv_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
slv_config.dst_maxburst = dma_burst;
if (i2c_dev->hw->has_mst_fifo)
val = I2C_MST_FIFO_CONTROL_TX_TRIG(dma_burst);
else
val = I2C_FIFO_CONTROL_TX_TRIG(dma_burst);
}
slv_config.device_fc = true;
err = dmaengine_slave_config(chan, &slv_config);
if (err) {
dev_err(i2c_dev->dev, "DMA config failed: %d\n", err);
dev_err(i2c_dev->dev, "falling back to PIO\n");
tegra_i2c_release_dma(i2c_dev);
i2c_dev->dma_mode = false;
} else {
goto out;
}
}
if (i2c_dev->hw->has_mst_fifo)
val = I2C_MST_FIFO_CONTROL_TX_TRIG(8) |
I2C_MST_FIFO_CONTROL_RX_TRIG(1);
else
val = I2C_FIFO_CONTROL_TX_TRIG(8) |
I2C_FIFO_CONTROL_RX_TRIG(1);
out:
i2c_writel(i2c_dev, val, reg);
}
static unsigned long tegra_i2c_poll_completion(struct tegra_i2c_dev *i2c_dev,
struct completion *complete,
unsigned int timeout_ms)
{
ktime_t ktime = ktime_get();
ktime_t ktimeout = ktime_add_ms(ktime, timeout_ms);
do {
u32 status = i2c_readl(i2c_dev, I2C_INT_STATUS);
if (status)
tegra_i2c_isr(i2c_dev->irq, i2c_dev);
if (completion_done(complete)) {
s64 delta = ktime_ms_delta(ktimeout, ktime);
return msecs_to_jiffies(delta) ?: 1;
}
ktime = ktime_get();
} while (ktime_before(ktime, ktimeout));
return 0;
}
static unsigned long tegra_i2c_wait_completion(struct tegra_i2c_dev *i2c_dev,
struct completion *complete,
unsigned int timeout_ms)
{
unsigned long ret;
if (i2c_dev->atomic_mode) {
ret = tegra_i2c_poll_completion(i2c_dev, complete, timeout_ms);
} else {
enable_irq(i2c_dev->irq);
ret = wait_for_completion_timeout(complete,
msecs_to_jiffies(timeout_ms));
disable_irq(i2c_dev->irq);
/*
* Under some rare circumstances (like running KASAN +
* NFS root) CPU, which handles interrupt, may stuck in
* uninterruptible state for a significant time. In this
* case we will get timeout if I2C transfer is running on
* a sibling CPU, despite of IRQ being raised.
*
* In order to handle this rare condition, the IRQ status
* needs to be checked after timeout.
*/
if (ret == 0)
ret = tegra_i2c_poll_completion(i2c_dev, complete, 0);
}
return ret;
}
static int tegra_i2c_issue_bus_clear(struct i2c_adapter *adap)
{
struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
u32 val, time_left;
int err;
reinit_completion(&i2c_dev->msg_complete);
val = FIELD_PREP(I2C_BC_SCLK_THRESHOLD, 9) | I2C_BC_STOP_COND |
I2C_BC_TERMINATE;
i2c_writel(i2c_dev, val, I2C_BUS_CLEAR_CNFG);
err = tegra_i2c_wait_for_config_load(i2c_dev);
if (err)
return err;
val |= I2C_BC_ENABLE;
i2c_writel(i2c_dev, val, I2C_BUS_CLEAR_CNFG);
tegra_i2c_unmask_irq(i2c_dev, I2C_INT_BUS_CLR_DONE);
time_left = tegra_i2c_wait_completion(i2c_dev, &i2c_dev->msg_complete, 50);
tegra_i2c_mask_irq(i2c_dev, I2C_INT_BUS_CLR_DONE);
if (time_left == 0) {
dev_err(i2c_dev->dev, "failed to clear bus\n");
return -ETIMEDOUT;
}
val = i2c_readl(i2c_dev, I2C_BUS_CLEAR_STATUS);
if (!(val & I2C_BC_STATUS)) {
dev_err(i2c_dev->dev, "un-recovered arbitration lost\n");
return -EIO;
}
return -EAGAIN;
}
static void tegra_i2c_push_packet_header(struct tegra_i2c_dev *i2c_dev,
struct i2c_msg *msg,
enum msg_end_type end_state)
{
u32 *dma_buf = i2c_dev->dma_buf;
u32 packet_header;
packet_header = FIELD_PREP(PACKET_HEADER0_HEADER_SIZE, 0) |
FIELD_PREP(PACKET_HEADER0_PROTOCOL,
PACKET_HEADER0_PROTOCOL_I2C) |
FIELD_PREP(PACKET_HEADER0_CONT_ID, i2c_dev->cont_id) |
FIELD_PREP(PACKET_HEADER0_PACKET_ID, 1);
if (i2c_dev->dma_mode && !i2c_dev->msg_read)
*dma_buf++ = packet_header;
else
i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
packet_header = msg->len - 1;
if (i2c_dev->dma_mode && !i2c_dev->msg_read)
*dma_buf++ = packet_header;
else
i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
packet_header = I2C_HEADER_IE_ENABLE;
if (end_state == MSG_END_CONTINUE)
packet_header |= I2C_HEADER_CONTINUE_XFER;
else if (end_state == MSG_END_REPEAT_START)
packet_header |= I2C_HEADER_REPEAT_START;
if (msg->flags & I2C_M_TEN) {
packet_header |= msg->addr;
packet_header |= I2C_HEADER_10BIT_ADDR;
} else {
packet_header |= msg->addr << I2C_HEADER_SLAVE_ADDR_SHIFT;
}
if (msg->flags & I2C_M_IGNORE_NAK)
packet_header |= I2C_HEADER_CONT_ON_NAK;
if (msg->flags & I2C_M_RD)
packet_header |= I2C_HEADER_READ;
if (i2c_dev->dma_mode && !i2c_dev->msg_read)
*dma_buf++ = packet_header;
else
i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
}
static int tegra_i2c_error_recover(struct tegra_i2c_dev *i2c_dev,
struct i2c_msg *msg)
{
if (i2c_dev->msg_err == I2C_ERR_NONE)
return 0;
tegra_i2c_init(i2c_dev);
/* start recovery upon arbitration loss in single master mode */
if (i2c_dev->msg_err == I2C_ERR_ARBITRATION_LOST) {
if (!i2c_dev->multimaster_mode)
return i2c_recover_bus(&i2c_dev->adapter);
return -EAGAIN;
}
if (i2c_dev->msg_err == I2C_ERR_NO_ACK) {
if (msg->flags & I2C_M_IGNORE_NAK)
return 0;
return -EREMOTEIO;
}
return -EIO;
}
static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
struct i2c_msg *msg,
enum msg_end_type end_state)
{
unsigned long time_left, xfer_time = 100;
size_t xfer_size;
u32 int_mask;
int err;
err = tegra_i2c_flush_fifos(i2c_dev);
if (err)
return err;
i2c_dev->msg_buf = msg->buf;
i2c_dev->msg_buf_remaining = msg->len;
i2c_dev->msg_err = I2C_ERR_NONE;
i2c_dev->msg_read = !!(msg->flags & I2C_M_RD);
reinit_completion(&i2c_dev->msg_complete);
if (i2c_dev->msg_read)
xfer_size = msg->len;
else
xfer_size = msg->len + I2C_PACKET_HEADER_SIZE;
xfer_size = ALIGN(xfer_size, BYTES_PER_FIFO_WORD);
i2c_dev->dma_mode = xfer_size > I2C_PIO_MODE_PREFERRED_LEN &&
i2c_dev->dma_buf && !i2c_dev->atomic_mode;
tegra_i2c_config_fifo_trig(i2c_dev, xfer_size);
/*
* Transfer time in mSec = Total bits / transfer rate
* Total bits = 9 bits per byte (including ACK bit) + Start & stop bits
*/
xfer_time += DIV_ROUND_CLOSEST(((xfer_size * 9) + 2) * MSEC_PER_SEC,
i2c_dev->bus_clk_rate);
int_mask = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
tegra_i2c_unmask_irq(i2c_dev, int_mask);
if (i2c_dev->dma_mode) {
if (i2c_dev->msg_read) {
dma_sync_single_for_device(i2c_dev->dev,
i2c_dev->dma_phys,
xfer_size, DMA_FROM_DEVICE);
err = tegra_i2c_dma_submit(i2c_dev, xfer_size);
if (err)
return err;
} else {
dma_sync_single_for_cpu(i2c_dev->dev,
i2c_dev->dma_phys,
xfer_size, DMA_TO_DEVICE);
}
}
tegra_i2c_push_packet_header(i2c_dev, msg, end_state);
if (!i2c_dev->msg_read) {
if (i2c_dev->dma_mode) {
memcpy(i2c_dev->dma_buf + I2C_PACKET_HEADER_SIZE,
msg->buf, msg->len);
dma_sync_single_for_device(i2c_dev->dev,
i2c_dev->dma_phys,
xfer_size, DMA_TO_DEVICE);
err = tegra_i2c_dma_submit(i2c_dev, xfer_size);
if (err)
return err;
} else {
tegra_i2c_fill_tx_fifo(i2c_dev);
}
}
if (i2c_dev->hw->has_per_pkt_xfer_complete_irq)
int_mask |= I2C_INT_PACKET_XFER_COMPLETE;
if (!i2c_dev->dma_mode) {
if (msg->flags & I2C_M_RD)
int_mask |= I2C_INT_RX_FIFO_DATA_REQ;
else if (i2c_dev->msg_buf_remaining)
int_mask |= I2C_INT_TX_FIFO_DATA_REQ;
}
tegra_i2c_unmask_irq(i2c_dev, int_mask);
dev_dbg(i2c_dev->dev, "unmasked IRQ: %02x\n",
i2c_readl(i2c_dev, I2C_INT_MASK));
if (i2c_dev->dma_mode) {
time_left = tegra_i2c_wait_completion(i2c_dev,
&i2c_dev->dma_complete,
xfer_time);
/*
* Synchronize DMA first, since dmaengine_terminate_sync()
* performs synchronization after the transfer's termination
* and we want to get a completion if transfer succeeded.
*/
dmaengine_synchronize(i2c_dev->msg_read ?
i2c_dev->rx_dma_chan :
i2c_dev->tx_dma_chan);
dmaengine_terminate_sync(i2c_dev->msg_read ?
i2c_dev->rx_dma_chan :
i2c_dev->tx_dma_chan);
if (!time_left && !completion_done(&i2c_dev->dma_complete)) {
dev_err(i2c_dev->dev, "DMA transfer timed out\n");
tegra_i2c_init(i2c_dev);
return -ETIMEDOUT;
}
if (i2c_dev->msg_read && i2c_dev->msg_err == I2C_ERR_NONE) {
dma_sync_single_for_cpu(i2c_dev->dev,
i2c_dev->dma_phys,
xfer_size, DMA_FROM_DEVICE);
memcpy(i2c_dev->msg_buf, i2c_dev->dma_buf, msg->len);
}
}
time_left = tegra_i2c_wait_completion(i2c_dev, &i2c_dev->msg_complete,
xfer_time);
tegra_i2c_mask_irq(i2c_dev, int_mask);
if (time_left == 0) {
dev_err(i2c_dev->dev, "I2C transfer timed out\n");
tegra_i2c_init(i2c_dev);
return -ETIMEDOUT;
}
dev_dbg(i2c_dev->dev, "transfer complete: %lu %d %d\n",
time_left, completion_done(&i2c_dev->msg_complete),
i2c_dev->msg_err);
i2c_dev->dma_mode = false;
err = tegra_i2c_error_recover(i2c_dev, msg);
if (err)
return err;
return 0;
}
static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
int num)
{
struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
int i, ret;
ret = pm_runtime_get_sync(i2c_dev->dev);
if (ret < 0) {
dev_err(i2c_dev->dev, "runtime resume failed %d\n", ret);
pm_runtime_put_noidle(i2c_dev->dev);
return ret;
}
for (i = 0; i < num; i++) {
enum msg_end_type end_type = MSG_END_STOP;
if (i < (num - 1)) {
/* check whether follow up message is coming */
if (msgs[i + 1].flags & I2C_M_NOSTART)
end_type = MSG_END_CONTINUE;
else
end_type = MSG_END_REPEAT_START;
}
ret = tegra_i2c_xfer_msg(i2c_dev, &msgs[i], end_type);
if (ret)
break;
}
pm_runtime_put(i2c_dev->dev);
return ret ?: i;
}
static int tegra_i2c_xfer_atomic(struct i2c_adapter *adap,
struct i2c_msg msgs[], int num)
{
struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
int ret;
i2c_dev->atomic_mode = true;
ret = tegra_i2c_xfer(adap, msgs, num);
i2c_dev->atomic_mode = false;
return ret;
}
static u32 tegra_i2c_func(struct i2c_adapter *adap)
{
struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
u32 ret = I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
I2C_FUNC_10BIT_ADDR | I2C_FUNC_PROTOCOL_MANGLING;
if (i2c_dev->hw->has_continue_xfer_support)
ret |= I2C_FUNC_NOSTART;
return ret;
}
static const struct i2c_algorithm tegra_i2c_algo = {
.master_xfer = tegra_i2c_xfer,
.master_xfer_atomic = tegra_i2c_xfer_atomic,
.functionality = tegra_i2c_func,
};
/* payload size is only 12 bit */
static const struct i2c_adapter_quirks tegra_i2c_quirks = {
.flags = I2C_AQ_NO_ZERO_LEN,
.max_read_len = SZ_4K,
.max_write_len = SZ_4K - I2C_PACKET_HEADER_SIZE,
};
static const struct i2c_adapter_quirks tegra194_i2c_quirks = {
.flags = I2C_AQ_NO_ZERO_LEN,
.max_write_len = SZ_64K - I2C_PACKET_HEADER_SIZE,
};
static struct i2c_bus_recovery_info tegra_i2c_recovery_info = {
.recover_bus = tegra_i2c_issue_bus_clear,
};
static const struct tegra_i2c_hw_feature tegra20_i2c_hw = {
.has_continue_xfer_support = false,
.has_per_pkt_xfer_complete_irq = false,
.clk_divisor_hs_mode = 3,
.clk_divisor_std_mode = 0,
.clk_divisor_fast_mode = 0,
.clk_divisor_fast_plus_mode = 0,
.has_config_load_reg = false,
.has_multi_master_mode = false,
.has_slcg_override_reg = false,
.has_mst_fifo = false,
.quirks = &tegra_i2c_quirks,
.supports_bus_clear = false,
.has_apb_dma = true,
.tlow_std_mode = 0x4,
.thigh_std_mode = 0x2,
.tlow_fast_fastplus_mode = 0x4,
.thigh_fast_fastplus_mode = 0x2,
.setup_hold_time_std_mode = 0x0,
.setup_hold_time_fast_fast_plus_mode = 0x0,
.setup_hold_time_hs_mode = 0x0,
.has_interface_timing_reg = false,
};
static const struct tegra_i2c_hw_feature tegra30_i2c_hw = {
.has_continue_xfer_support = true,
.has_per_pkt_xfer_complete_irq = false,
.clk_divisor_hs_mode = 3,
.clk_divisor_std_mode = 0,
.clk_divisor_fast_mode = 0,
.clk_divisor_fast_plus_mode = 0,
.has_config_load_reg = false,
.has_multi_master_mode = false,
.has_slcg_override_reg = false,
.has_mst_fifo = false,
.quirks = &tegra_i2c_quirks,
.supports_bus_clear = false,
.has_apb_dma = true,
.tlow_std_mode = 0x4,
.thigh_std_mode = 0x2,
.tlow_fast_fastplus_mode = 0x4,
.thigh_fast_fastplus_mode = 0x2,
.setup_hold_time_std_mode = 0x0,
.setup_hold_time_fast_fast_plus_mode = 0x0,
.setup_hold_time_hs_mode = 0x0,
.has_interface_timing_reg = false,
};
static const struct tegra_i2c_hw_feature tegra114_i2c_hw = {
.has_continue_xfer_support = true,
.has_per_pkt_xfer_complete_irq = true,
.clk_divisor_hs_mode = 1,
.clk_divisor_std_mode = 0x19,
.clk_divisor_fast_mode = 0x19,
.clk_divisor_fast_plus_mode = 0x10,
.has_config_load_reg = false,
.has_multi_master_mode = false,
.has_slcg_override_reg = false,
.has_mst_fifo = false,
.quirks = &tegra_i2c_quirks,
.supports_bus_clear = true,
.has_apb_dma = true,
.tlow_std_mode = 0x4,
.thigh_std_mode = 0x2,
.tlow_fast_fastplus_mode = 0x4,
.thigh_fast_fastplus_mode = 0x2,
.setup_hold_time_std_mode = 0x0,
.setup_hold_time_fast_fast_plus_mode = 0x0,
.setup_hold_time_hs_mode = 0x0,
.has_interface_timing_reg = false,
};
static const struct tegra_i2c_hw_feature tegra124_i2c_hw = {
.has_continue_xfer_support = true,
.has_per_pkt_xfer_complete_irq = true,
.clk_divisor_hs_mode = 1,
.clk_divisor_std_mode = 0x19,
.clk_divisor_fast_mode = 0x19,
.clk_divisor_fast_plus_mode = 0x10,
.has_config_load_reg = true,
.has_multi_master_mode = false,
.has_slcg_override_reg = true,
.has_mst_fifo = false,
.quirks = &tegra_i2c_quirks,
.supports_bus_clear = true,
.has_apb_dma = true,
.tlow_std_mode = 0x4,
.thigh_std_mode = 0x2,
.tlow_fast_fastplus_mode = 0x4,
.thigh_fast_fastplus_mode = 0x2,
.setup_hold_time_std_mode = 0x0,
.setup_hold_time_fast_fast_plus_mode = 0x0,
.setup_hold_time_hs_mode = 0x0,
.has_interface_timing_reg = true,
};
static const struct tegra_i2c_hw_feature tegra210_i2c_hw = {
.has_continue_xfer_support = true,
.has_per_pkt_xfer_complete_irq = true,
.clk_divisor_hs_mode = 1,
.clk_divisor_std_mode = 0x19,
.clk_divisor_fast_mode = 0x19,
.clk_divisor_fast_plus_mode = 0x10,
.has_config_load_reg = true,
.has_multi_master_mode = false,
.has_slcg_override_reg = true,
.has_mst_fifo = false,
.quirks = &tegra_i2c_quirks,
.supports_bus_clear = true,
.has_apb_dma = true,
.tlow_std_mode = 0x4,
.thigh_std_mode = 0x2,
.tlow_fast_fastplus_mode = 0x4,
.thigh_fast_fastplus_mode = 0x2,
.setup_hold_time_std_mode = 0,
.setup_hold_time_fast_fast_plus_mode = 0,
.setup_hold_time_hs_mode = 0,
.has_interface_timing_reg = true,
};
static const struct tegra_i2c_hw_feature tegra186_i2c_hw = {
.has_continue_xfer_support = true,
.has_per_pkt_xfer_complete_irq = true,
.clk_divisor_hs_mode = 1,
.clk_divisor_std_mode = 0x16,
.clk_divisor_fast_mode = 0x19,
.clk_divisor_fast_plus_mode = 0x10,
.has_config_load_reg = true,
.has_multi_master_mode = false,
.has_slcg_override_reg = true,
.has_mst_fifo = false,
.quirks = &tegra_i2c_quirks,
.supports_bus_clear = true,
.has_apb_dma = false,
.tlow_std_mode = 0x4,
.thigh_std_mode = 0x3,
.tlow_fast_fastplus_mode = 0x4,
.thigh_fast_fastplus_mode = 0x2,
.setup_hold_time_std_mode = 0,
.setup_hold_time_fast_fast_plus_mode = 0,
.setup_hold_time_hs_mode = 0,
.has_interface_timing_reg = true,
};
static const struct tegra_i2c_hw_feature tegra194_i2c_hw = {
.has_continue_xfer_support = true,
.has_per_pkt_xfer_complete_irq = true,
.clk_divisor_hs_mode = 1,
.clk_divisor_std_mode = 0x4f,
.clk_divisor_fast_mode = 0x3c,
.clk_divisor_fast_plus_mode = 0x16,
.has_config_load_reg = true,
.has_multi_master_mode = true,
.has_slcg_override_reg = true,
.has_mst_fifo = true,
.quirks = &tegra194_i2c_quirks,
.supports_bus_clear = true,
.has_apb_dma = false,
.tlow_std_mode = 0x8,
.thigh_std_mode = 0x7,
.tlow_fast_fastplus_mode = 0x2,
.thigh_fast_fastplus_mode = 0x2,
.setup_hold_time_std_mode = 0x08080808,
.setup_hold_time_fast_fast_plus_mode = 0x02020202,
.setup_hold_time_hs_mode = 0x090909,
.has_interface_timing_reg = true,
};
static const struct of_device_id tegra_i2c_of_match[] = {
{ .compatible = "nvidia,tegra194-i2c", .data = &tegra194_i2c_hw, },
{ .compatible = "nvidia,tegra186-i2c", .data = &tegra186_i2c_hw, },
{ .compatible = "nvidia,tegra210-i2c-vi", .data = &tegra210_i2c_hw, },
{ .compatible = "nvidia,tegra210-i2c", .data = &tegra210_i2c_hw, },
{ .compatible = "nvidia,tegra124-i2c", .data = &tegra124_i2c_hw, },
{ .compatible = "nvidia,tegra114-i2c", .data = &tegra114_i2c_hw, },
{ .compatible = "nvidia,tegra30-i2c", .data = &tegra30_i2c_hw, },
{ .compatible = "nvidia,tegra20-i2c", .data = &tegra20_i2c_hw, },
{ .compatible = "nvidia,tegra20-i2c-dvc", .data = &tegra20_i2c_hw, },
{},
};
MODULE_DEVICE_TABLE(of, tegra_i2c_of_match);
static void tegra_i2c_parse_dt(struct tegra_i2c_dev *i2c_dev)
{
struct device_node *np = i2c_dev->dev->of_node;
bool multi_mode;
int err;
err = of_property_read_u32(np, "clock-frequency",
&i2c_dev->bus_clk_rate);
if (err)
i2c_dev->bus_clk_rate = I2C_MAX_STANDARD_MODE_FREQ;
multi_mode = of_property_read_bool(np, "multi-master");
i2c_dev->multimaster_mode = multi_mode;
if (of_device_is_compatible(np, "nvidia,tegra20-i2c-dvc"))
i2c_dev->is_dvc = true;
if (of_device_is_compatible(np, "nvidia,tegra210-i2c-vi"))
i2c_dev->is_vi = true;
}
static int tegra_i2c_init_clocks(struct tegra_i2c_dev *i2c_dev)
{
int err;
i2c_dev->clocks[i2c_dev->nclocks++].id = "div-clk";
if (i2c_dev->hw == &tegra20_i2c_hw || i2c_dev->hw == &tegra30_i2c_hw)
i2c_dev->clocks[i2c_dev->nclocks++].id = "fast-clk";
if (i2c_dev->is_vi)
i2c_dev->clocks[i2c_dev->nclocks++].id = "slow";
err = devm_clk_bulk_get(i2c_dev->dev, i2c_dev->nclocks,
i2c_dev->clocks);
if (err)
return err;
err = clk_bulk_prepare(i2c_dev->nclocks, i2c_dev->clocks);
if (err)
return err;
i2c_dev->div_clk = i2c_dev->clocks[0].clk;
if (!i2c_dev->multimaster_mode)
return 0;
err = clk_enable(i2c_dev->div_clk);
if (err) {
dev_err(i2c_dev->dev, "failed to enable div-clk: %d\n", err);
goto unprepare_clocks;
}
return 0;
unprepare_clocks:
clk_bulk_unprepare(i2c_dev->nclocks, i2c_dev->clocks);
return err;
}
static void tegra_i2c_release_clocks(struct tegra_i2c_dev *i2c_dev)
{
if (i2c_dev->multimaster_mode)
clk_disable(i2c_dev->div_clk);
clk_bulk_unprepare(i2c_dev->nclocks, i2c_dev->clocks);
}
static int tegra_i2c_init_hardware(struct tegra_i2c_dev *i2c_dev)
{
int ret;
ret = pm_runtime_get_sync(i2c_dev->dev);
if (ret < 0)
dev_err(i2c_dev->dev, "runtime resume failed: %d\n", ret);
else
ret = tegra_i2c_init(i2c_dev);
pm_runtime_put(i2c_dev->dev);
return ret;
}
static int tegra_i2c_probe(struct platform_device *pdev)
{
struct tegra_i2c_dev *i2c_dev;
struct resource *res;
int err;
i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
if (!i2c_dev)
return -ENOMEM;
platform_set_drvdata(pdev, i2c_dev);
init_completion(&i2c_dev->msg_complete);
init_completion(&i2c_dev->dma_complete);
i2c_dev->hw = of_device_get_match_data(&pdev->dev);
i2c_dev->cont_id = pdev->id;
i2c_dev->dev = &pdev->dev;
i2c_dev->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
if (IS_ERR(i2c_dev->base))
return PTR_ERR(i2c_dev->base);
i2c_dev->base_phys = res->start;
err = platform_get_irq(pdev, 0);
if (err < 0)
return err;
i2c_dev->irq = err;
/* interrupt will be enabled during of transfer time */
irq_set_status_flags(i2c_dev->irq, IRQ_NOAUTOEN);
err = devm_request_irq(i2c_dev->dev, i2c_dev->irq, tegra_i2c_isr,
IRQF_NO_SUSPEND, dev_name(i2c_dev->dev),
i2c_dev);
if (err)
return err;
i2c_dev->rst = devm_reset_control_get_exclusive(i2c_dev->dev, "i2c");
if (IS_ERR(i2c_dev->rst)) {
dev_err_probe(i2c_dev->dev, PTR_ERR(i2c_dev->rst),
"failed to get reset control\n");
return PTR_ERR(i2c_dev->rst);
}
tegra_i2c_parse_dt(i2c_dev);
err = tegra_i2c_init_clocks(i2c_dev);
if (err)
return err;
err = tegra_i2c_init_dma(i2c_dev);
if (err)
goto release_clocks;
/*
* VI I2C is in VE power domain which is not always ON and not
* IRQ-safe. Thus, IRQ-safe device shouldn't be attached to a
* non IRQ-safe domain because this prevents powering off the power
* domain.
*
* VI I2C device shouldn't be marked as IRQ-safe because VI I2C won't
* be used for atomic transfers.
*/
if (!i2c_dev->is_vi)
pm_runtime_irq_safe(i2c_dev->dev);
pm_runtime_enable(i2c_dev->dev);
err = tegra_i2c_init_hardware(i2c_dev);
if (err)
goto release_rpm;
i2c_set_adapdata(&i2c_dev->adapter, i2c_dev);
i2c_dev->adapter.dev.of_node = i2c_dev->dev->of_node;
i2c_dev->adapter.dev.parent = i2c_dev->dev;
i2c_dev->adapter.retries = 1;
i2c_dev->adapter.timeout = 6 * HZ;
i2c_dev->adapter.quirks = i2c_dev->hw->quirks;
i2c_dev->adapter.owner = THIS_MODULE;
i2c_dev->adapter.class = I2C_CLASS_DEPRECATED;
i2c_dev->adapter.algo = &tegra_i2c_algo;
i2c_dev->adapter.nr = pdev->id;
if (i2c_dev->hw->supports_bus_clear)
i2c_dev->adapter.bus_recovery_info = &tegra_i2c_recovery_info;
strlcpy(i2c_dev->adapter.name, dev_name(i2c_dev->dev),
sizeof(i2c_dev->adapter.name));
err = i2c_add_numbered_adapter(&i2c_dev->adapter);
if (err)
goto release_rpm;
return 0;
release_rpm:
pm_runtime_disable(i2c_dev->dev);
tegra_i2c_release_dma(i2c_dev);
release_clocks:
tegra_i2c_release_clocks(i2c_dev);
return err;
}
static int tegra_i2c_remove(struct platform_device *pdev)
{
struct tegra_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
i2c_del_adapter(&i2c_dev->adapter);
pm_runtime_disable(i2c_dev->dev);
tegra_i2c_release_dma(i2c_dev);
tegra_i2c_release_clocks(i2c_dev);
return 0;
}
static int __maybe_unused tegra_i2c_runtime_resume(struct device *dev)
{
struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
int err;
err = pinctrl_pm_select_default_state(dev);
if (err)
return err;
err = clk_bulk_enable(i2c_dev->nclocks, i2c_dev->clocks);
if (err)
return err;
/*
* VI I2C device is attached to VE power domain which goes through
* power ON/OFF during runtime PM resume/suspend, meaning that
* controller needs to be re-initialized after power ON.
*/
if (i2c_dev->is_vi) {
err = tegra_i2c_init(i2c_dev);
if (err)
goto disable_clocks;
}
return 0;
disable_clocks:
clk_bulk_disable(i2c_dev->nclocks, i2c_dev->clocks);
return err;
}
static int __maybe_unused tegra_i2c_runtime_suspend(struct device *dev)
{
struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
clk_bulk_disable(i2c_dev->nclocks, i2c_dev->clocks);
return pinctrl_pm_select_idle_state(dev);
}
static int __maybe_unused tegra_i2c_suspend(struct device *dev)
{
struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
int err;
i2c_mark_adapter_suspended(&i2c_dev->adapter);
if (!pm_runtime_status_suspended(dev)) {
err = tegra_i2c_runtime_suspend(dev);
if (err)
return err;
}
return 0;
}
static int __maybe_unused tegra_i2c_resume(struct device *dev)
{
struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
int err;
/*
* We need to ensure that clocks are enabled so that registers can be
* restored in tegra_i2c_init().
*/
err = tegra_i2c_runtime_resume(dev);
if (err)
return err;
err = tegra_i2c_init(i2c_dev);
if (err)
return err;
/*
* In case we are runtime suspended, disable clocks again so that we
* don't unbalance the clock reference counts during the next runtime
* resume transition.
*/
if (pm_runtime_status_suspended(dev)) {
err = tegra_i2c_runtime_suspend(dev);
if (err)
return err;
}
i2c_mark_adapter_resumed(&i2c_dev->adapter);
return 0;
}
static const struct dev_pm_ops tegra_i2c_pm = {
SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(tegra_i2c_suspend, tegra_i2c_resume)
SET_RUNTIME_PM_OPS(tegra_i2c_runtime_suspend, tegra_i2c_runtime_resume,
NULL)
};
static struct platform_driver tegra_i2c_driver = {
.probe = tegra_i2c_probe,
.remove = tegra_i2c_remove,
.driver = {
.name = "tegra-i2c",
.of_match_table = tegra_i2c_of_match,
.pm = &tegra_i2c_pm,
},
};
module_platform_driver(tegra_i2c_driver);
MODULE_DESCRIPTION("NVIDIA Tegra I2C Bus Controller driver");
MODULE_AUTHOR("Colin Cross");
MODULE_LICENSE("GPL v2");
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