diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-owl.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-owl.c | 75 |
1 files changed, 56 insertions, 19 deletions
diff --git a/drivers/i2c/busses/i2c-owl.c b/drivers/i2c/busses/i2c-owl.c index 9918b2a0b909..98882fe4e965 100644 --- a/drivers/i2c/busses/i2c-owl.c +++ b/drivers/i2c/busses/i2c-owl.c @@ -14,6 +14,7 @@ #include <linux/i2c.h> #include <linux/interrupt.h> #include <linux/io.h> +#include <linux/iopoll.h> #include <linux/module.h> #include <linux/of_device.h> @@ -76,6 +77,7 @@ #define OWL_I2C_FIFOCTL_TFR BIT(2) /* I2Cc_FIFOSTAT Bit Mask */ +#define OWL_I2C_FIFOSTAT_CECB BIT(0) #define OWL_I2C_FIFOSTAT_RNB BIT(1) #define OWL_I2C_FIFOSTAT_RFE BIT(2) #define OWL_I2C_FIFOSTAT_TFF BIT(5) @@ -83,7 +85,8 @@ #define OWL_I2C_FIFOSTAT_RFD GENMASK(15, 8) /* I2C bus timeout */ -#define OWL_I2C_TIMEOUT msecs_to_jiffies(4 * 1000) +#define OWL_I2C_TIMEOUT_MS (4 * 1000) +#define OWL_I2C_TIMEOUT msecs_to_jiffies(OWL_I2C_TIMEOUT_MS) #define OWL_I2C_MAX_RETRIES 50 @@ -161,14 +164,11 @@ static void owl_i2c_set_freq(struct owl_i2c_dev *i2c_dev) writel(OWL_I2C_DIV_FACTOR(val), i2c_dev->base + OWL_I2C_REG_CLKDIV); } -static irqreturn_t owl_i2c_interrupt(int irq, void *_dev) +static void owl_i2c_xfer_data(struct owl_i2c_dev *i2c_dev) { - struct owl_i2c_dev *i2c_dev = _dev; struct i2c_msg *msg = i2c_dev->msg; unsigned int stat, fifostat; - spin_lock(&i2c_dev->lock); - i2c_dev->err = 0; /* Handle NACK from slave */ @@ -178,7 +178,7 @@ static irqreturn_t owl_i2c_interrupt(int irq, void *_dev) /* Clear NACK error bit by writing "1" */ owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_FIFOSTAT, OWL_I2C_FIFOSTAT_RNB, true); - goto stop; + return; } /* Handle bus error */ @@ -188,7 +188,7 @@ static irqreturn_t owl_i2c_interrupt(int irq, void *_dev) /* Clear BUS error bit by writing "1" */ owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_STAT, OWL_I2C_STAT_BEB, true); - goto stop; + return; } /* Handle FIFO read */ @@ -206,8 +206,16 @@ static irqreturn_t owl_i2c_interrupt(int irq, void *_dev) i2c_dev->base + OWL_I2C_REG_TXDAT); } } +} + +static irqreturn_t owl_i2c_interrupt(int irq, void *_dev) +{ + struct owl_i2c_dev *i2c_dev = _dev; + + spin_lock(&i2c_dev->lock); + + owl_i2c_xfer_data(i2c_dev); -stop: /* Clear pending interrupts */ owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_STAT, OWL_I2C_STAT_IRQP, true); @@ -240,8 +248,8 @@ static int owl_i2c_check_bus_busy(struct i2c_adapter *adap) return 0; } -static int owl_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, - int num) +static int owl_i2c_xfer_common(struct i2c_adapter *adap, struct i2c_msg *msgs, + int num, bool atomic) { struct owl_i2c_dev *i2c_dev = i2c_get_adapdata(adap); struct i2c_msg *msg; @@ -285,11 +293,12 @@ static int owl_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, goto err_exit; } - reinit_completion(&i2c_dev->msg_complete); + if (!atomic) + reinit_completion(&i2c_dev->msg_complete); - /* Enable I2C controller interrupt */ + /* Enable/disable I2C controller interrupt */ owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_CTL, - OWL_I2C_CTL_IRQE, true); + OWL_I2C_CTL_IRQE, !atomic); /* * Select: FIFO enable, Master mode, Stop enable, Data count enable, @@ -357,20 +366,33 @@ static int owl_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, spin_unlock_irqrestore(&i2c_dev->lock, flags); - time_left = wait_for_completion_timeout(&i2c_dev->msg_complete, - adap->timeout); + if (atomic) { + /* Wait for Command Execute Completed or NACK Error bits */ + ret = readl_poll_timeout_atomic(i2c_dev->base + OWL_I2C_REG_FIFOSTAT, + val, val & (OWL_I2C_FIFOSTAT_CECB | + OWL_I2C_FIFOSTAT_RNB), + 10, OWL_I2C_TIMEOUT_MS * 1000); + } else { + time_left = wait_for_completion_timeout(&i2c_dev->msg_complete, + adap->timeout); + if (!time_left) + ret = -ETIMEDOUT; + } spin_lock_irqsave(&i2c_dev->lock, flags); - if (time_left == 0) { + + if (ret) { dev_err(&adap->dev, "Transaction timed out\n"); /* Send stop condition and release the bus */ owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_CTL, OWL_I2C_CTL_GBCC_STOP | OWL_I2C_CTL_RB, true); - ret = -ETIMEDOUT; goto err_exit; } + if (atomic) + owl_i2c_xfer_data(i2c_dev); + ret = i2c_dev->err < 0 ? i2c_dev->err : num; err_exit: @@ -384,9 +406,22 @@ unlocked_err_exit: return ret; } +static int owl_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, + int num) +{ + return owl_i2c_xfer_common(adap, msgs, num, false); +} + +static int owl_i2c_xfer_atomic(struct i2c_adapter *adap, + struct i2c_msg *msgs, int num) +{ + return owl_i2c_xfer_common(adap, msgs, num, true); +} + static const struct i2c_algorithm owl_i2c_algorithm = { - .master_xfer = owl_i2c_master_xfer, - .functionality = owl_i2c_func, + .master_xfer = owl_i2c_xfer, + .master_xfer_atomic = owl_i2c_xfer_atomic, + .functionality = owl_i2c_func, }; static const struct i2c_adapter_quirks owl_i2c_quirks = { @@ -473,6 +508,7 @@ disable_clk: } static const struct of_device_id owl_i2c_of_match[] = { + { .compatible = "actions,s500-i2c" }, { .compatible = "actions,s700-i2c" }, { .compatible = "actions,s900-i2c" }, { /* sentinel */ } @@ -484,6 +520,7 @@ static struct platform_driver owl_i2c_driver = { .driver = { .name = "owl-i2c", .of_match_table = of_match_ptr(owl_i2c_of_match), + .probe_type = PROBE_PREFER_ASYNCHRONOUS, }, }; module_platform_driver(owl_i2c_driver); |