diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-designware-master.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-designware-master.c | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c index 418c233075d3..ae691884d071 100644 --- a/drivers/i2c/busses/i2c-designware-master.c +++ b/drivers/i2c/busses/i2c-designware-master.c @@ -25,11 +25,13 @@ #include <linux/err.h> #include <linux/errno.h> #include <linux/export.h> +#include <linux/gpio/consumer.h> #include <linux/i2c.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/module.h> #include <linux/pm_runtime.h> +#include <linux/reset.h> #include "i2c-designware-core.h" @@ -443,6 +445,7 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) if (!wait_for_completion_timeout(&dev->cmd_complete, adap->timeout)) { dev_err(dev->dev, "controller timed out\n"); /* i2c_dw_init implicitly disables the adapter */ + i2c_recover_bus(&dev->adapter); i2c_dw_init_master(dev); ret = -ETIMEDOUT; goto done; @@ -613,6 +616,56 @@ static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id) return IRQ_HANDLED; } +static void i2c_dw_prepare_recovery(struct i2c_adapter *adap) +{ + struct dw_i2c_dev *dev = i2c_get_adapdata(adap); + + i2c_dw_disable(dev); + reset_control_assert(dev->rst); + i2c_dw_prepare_clk(dev, false); +} + +static void i2c_dw_unprepare_recovery(struct i2c_adapter *adap) +{ + struct dw_i2c_dev *dev = i2c_get_adapdata(adap); + + i2c_dw_prepare_clk(dev, true); + reset_control_deassert(dev->rst); + i2c_dw_init_master(dev); +} + +static int i2c_dw_init_recovery_info(struct dw_i2c_dev *dev) +{ + struct i2c_bus_recovery_info *rinfo = &dev->rinfo; + struct i2c_adapter *adap = &dev->adapter; + struct gpio_desc *gpio; + int r; + + gpio = devm_gpiod_get(dev->dev, "scl", GPIOD_OUT_HIGH); + if (IS_ERR(gpio)) { + r = PTR_ERR(gpio); + if (r == -ENOENT) + return 0; + return r; + } + rinfo->scl_gpiod = gpio; + + gpio = devm_gpiod_get_optional(dev->dev, "sda", GPIOD_IN); + if (IS_ERR(gpio)) + return PTR_ERR(gpio); + rinfo->sda_gpiod = gpio; + + rinfo->recover_bus = i2c_generic_scl_recovery; + rinfo->prepare_recovery = i2c_dw_prepare_recovery; + rinfo->unprepare_recovery = i2c_dw_unprepare_recovery; + adap->bus_recovery_info = rinfo; + + dev_info(dev->dev, "running with gpio recovery mode! scl%s", + rinfo->sda_gpiod ? ",sda" : ""); + + return 0; +} + int i2c_dw_probe(struct dw_i2c_dev *dev) { struct i2c_adapter *adap = &dev->adapter; @@ -652,6 +705,10 @@ int i2c_dw_probe(struct dw_i2c_dev *dev) return ret; } + ret = i2c_dw_init_recovery_info(dev); + if (ret) + return ret; + /* * Increment PM usage count during adapter registration in order to * avoid possible spurious runtime suspend when adapter device is |