| Message ID | 20210317065359.3109394-9-xiaoning.wang@nxp.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | i2c: imx-lpi2c: New features and bug fixes | expand |
> From: Clark Wang <xiaoning.wang@nxp.com> > Sent: Wednesday, March 17, 2021 2:54 PM > > Add bus recovery feature for LPI2C. > Need add gpio pinctrl, scl-gpios and sda-gpios configuration in dts. > Pls also update dt-binding first > Signed-off-by: Clark Wang <xiaoning.wang@nxp.com> > --- > drivers/i2c/busses/i2c-imx-lpi2c.c | 83 ++++++++++++++++++++++++++++++ > 1 file changed, 83 insertions(+) > > diff --git a/drivers/i2c/busses/i2c-imx-lpi2c.c > b/drivers/i2c/busses/i2c-imx-lpi2c.c > index c0cb77c66090..7216a393095d 100644 > --- a/drivers/i2c/busses/i2c-imx-lpi2c.c > +++ b/drivers/i2c/busses/i2c-imx-lpi2c.c > @@ -18,6 +18,7 @@ > #include <linux/module.h> > #include <linux/of.h> > #include <linux/of_device.h> > +#include <linux/of_gpio.h> > #include <linux/pinctrl/consumer.h> > #include <linux/platform_device.h> > #include <linux/pm_runtime.h> > @@ -108,6 +109,11 @@ struct lpi2c_imx_struct { > unsigned int txfifosize; > unsigned int rxfifosize; > enum lpi2c_imx_mode mode; > + > + struct i2c_bus_recovery_info rinfo; > + struct pinctrl *pinctrl; > + struct pinctrl_state *pinctrl_pins_default; > + struct pinctrl_state *pinctrl_pins_gpio; > }; > > static void lpi2c_imx_intctrl(struct lpi2c_imx_struct *lpi2c_imx, @@ -135,6 > +141,8 @@ static int lpi2c_imx_bus_busy(struct lpi2c_imx_struct *lpi2c_imx) > > if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) { > dev_dbg(&lpi2c_imx->adapter.dev, "bus not work\n"); > + if (lpi2c_imx->adapter.bus_recovery_info) > + i2c_recover_bus(&lpi2c_imx->adapter); > return -ETIMEDOUT; > } > schedule(); > @@ -192,6 +200,8 @@ static void lpi2c_imx_stop(struct lpi2c_imx_struct > *lpi2c_imx) > > if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) { > dev_dbg(&lpi2c_imx->adapter.dev, "stop timeout\n"); > + if (lpi2c_imx->adapter.bus_recovery_info) > + i2c_recover_bus(&lpi2c_imx->adapter); > break; > } > schedule(); > @@ -329,6 +339,8 @@ static int lpi2c_imx_txfifo_empty(struct > lpi2c_imx_struct *lpi2c_imx) > > if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) { > dev_dbg(&lpi2c_imx->adapter.dev, "txfifo empty timeout\n"); > + if (lpi2c_imx->adapter.bus_recovery_info) > + i2c_recover_bus(&lpi2c_imx->adapter); > return -ETIMEDOUT; > } > schedule(); > @@ -528,6 +540,71 @@ static irqreturn_t lpi2c_imx_isr(int irq, void *dev_id) > return IRQ_HANDLED; > } > > +static void lpi2c_imx_prepare_recovery(struct i2c_adapter *adap) { > + struct lpi2c_imx_struct *lpi2c_imx; > + > + lpi2c_imx = container_of(adap, struct lpi2c_imx_struct, adapter); > + > + pinctrl_select_state(lpi2c_imx->pinctrl, > +lpi2c_imx->pinctrl_pins_gpio); } > + > +static void lpi2c_imx_unprepare_recovery(struct i2c_adapter *adap) { > + struct lpi2c_imx_struct *lpi2c_imx; > + > + lpi2c_imx = container_of(adap, struct lpi2c_imx_struct, adapter); > + > + pinctrl_select_state(lpi2c_imx->pinctrl, > +lpi2c_imx->pinctrl_pins_default); } > + > +/* > + * We switch SCL and SDA to their GPIO function and do some bitbanging > + * for bus recovery. These alternative pinmux settings can be > + * described in the device tree by a separate pinctrl state "gpio". If > + * this is missing this is not a big problem, the only implication is > + * that we can't do bus recovery. > + */ > +static int lpi2c_imx_init_recovery_info(struct lpi2c_imx_struct *lpi2c_imx, > + struct platform_device *pdev) > +{ > + struct i2c_bus_recovery_info *rinfo = &lpi2c_imx->rinfo; > + > + lpi2c_imx->pinctrl = devm_pinctrl_get(&pdev->dev); > + if (!lpi2c_imx->pinctrl || IS_ERR(lpi2c_imx->pinctrl)) { > + dev_info(&pdev->dev, "can't get pinctrl, bus recovery not > supported\n"); > + return PTR_ERR(lpi2c_imx->pinctrl); > + } > + > + lpi2c_imx->pinctrl_pins_default = pinctrl_lookup_state(lpi2c_imx->pinctrl, > + PINCTRL_STATE_DEFAULT); > + lpi2c_imx->pinctrl_pins_gpio = pinctrl_lookup_state(lpi2c_imx->pinctrl, > + "gpio"); > + rinfo->sda_gpiod = devm_gpiod_get(&pdev->dev, "sda", GPIOD_IN); > + rinfo->scl_gpiod = devm_gpiod_get(&pdev->dev, "scl", > +GPIOD_OUT_HIGH_OPEN_DRAIN); > + > + if (PTR_ERR(rinfo->sda_gpiod) == -EPROBE_DEFER || > + PTR_ERR(rinfo->scl_gpiod) == -EPROBE_DEFER) { > + return -EPROBE_DEFER; > + } else if (IS_ERR(rinfo->sda_gpiod) || > + IS_ERR(rinfo->scl_gpiod) || > + IS_ERR(lpi2c_imx->pinctrl_pins_default) || > + IS_ERR(lpi2c_imx->pinctrl_pins_gpio)) { > + dev_dbg(&pdev->dev, "recovery information incomplete\n"); > + return 0; > + } > + > + dev_info(&pdev->dev, "using scl%s for recovery\n", > + rinfo->sda_gpiod ? ",sda" : ""); > + > + rinfo->prepare_recovery = lpi2c_imx_prepare_recovery; > + rinfo->unprepare_recovery = lpi2c_imx_unprepare_recovery; > + rinfo->recover_bus = i2c_generic_scl_recovery; > + lpi2c_imx->adapter.bus_recovery_info = rinfo; > + > + return 0; > +} > + > static u32 lpi2c_imx_func(struct i2c_adapter *adapter) { > return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | @@ -607,6 +684,12 > @@ static int lpi2c_imx_probe(struct platform_device *pdev) > > pm_runtime_put(&pdev->dev); > > + /* Init optional bus recovery function */ > + ret = lpi2c_imx_init_recovery_info(lpi2c_imx, pdev); > + /* Give it another chance if pinctrl used is not ready yet */ > + if (ret == -EPROBE_DEFER) > + goto rpm_disable; > + > ret = i2c_add_adapter(&lpi2c_imx->adapter); > if (ret) > goto rpm_disable; > -- > 2.25.1
diff --git a/drivers/i2c/busses/i2c-imx-lpi2c.c b/drivers/i2c/busses/i2c-imx-lpi2c.c index c0cb77c66090..7216a393095d 100644 --- a/drivers/i2c/busses/i2c-imx-lpi2c.c +++ b/drivers/i2c/busses/i2c-imx-lpi2c.c @@ -18,6 +18,7 @@ #include <linux/module.h> #include <linux/of.h> #include <linux/of_device.h> +#include <linux/of_gpio.h> #include <linux/pinctrl/consumer.h> #include <linux/platform_device.h> #include <linux/pm_runtime.h> @@ -108,6 +109,11 @@ struct lpi2c_imx_struct { unsigned int txfifosize; unsigned int rxfifosize; enum lpi2c_imx_mode mode; + + struct i2c_bus_recovery_info rinfo; + struct pinctrl *pinctrl; + struct pinctrl_state *pinctrl_pins_default; + struct pinctrl_state *pinctrl_pins_gpio; }; static void lpi2c_imx_intctrl(struct lpi2c_imx_struct *lpi2c_imx, @@ -135,6 +141,8 @@ static int lpi2c_imx_bus_busy(struct lpi2c_imx_struct *lpi2c_imx) if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) { dev_dbg(&lpi2c_imx->adapter.dev, "bus not work\n"); + if (lpi2c_imx->adapter.bus_recovery_info) + i2c_recover_bus(&lpi2c_imx->adapter); return -ETIMEDOUT; } schedule(); @@ -192,6 +200,8 @@ static void lpi2c_imx_stop(struct lpi2c_imx_struct *lpi2c_imx) if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) { dev_dbg(&lpi2c_imx->adapter.dev, "stop timeout\n"); + if (lpi2c_imx->adapter.bus_recovery_info) + i2c_recover_bus(&lpi2c_imx->adapter); break; } schedule(); @@ -329,6 +339,8 @@ static int lpi2c_imx_txfifo_empty(struct lpi2c_imx_struct *lpi2c_imx) if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) { dev_dbg(&lpi2c_imx->adapter.dev, "txfifo empty timeout\n"); + if (lpi2c_imx->adapter.bus_recovery_info) + i2c_recover_bus(&lpi2c_imx->adapter); return -ETIMEDOUT; } schedule(); @@ -528,6 +540,71 @@ static irqreturn_t lpi2c_imx_isr(int irq, void *dev_id) return IRQ_HANDLED; } +static void lpi2c_imx_prepare_recovery(struct i2c_adapter *adap) +{ + struct lpi2c_imx_struct *lpi2c_imx; + + lpi2c_imx = container_of(adap, struct lpi2c_imx_struct, adapter); + + pinctrl_select_state(lpi2c_imx->pinctrl, lpi2c_imx->pinctrl_pins_gpio); +} + +static void lpi2c_imx_unprepare_recovery(struct i2c_adapter *adap) +{ + struct lpi2c_imx_struct *lpi2c_imx; + + lpi2c_imx = container_of(adap, struct lpi2c_imx_struct, adapter); + + pinctrl_select_state(lpi2c_imx->pinctrl, lpi2c_imx->pinctrl_pins_default); +} + +/* + * We switch SCL and SDA to their GPIO function and do some bitbanging + * for bus recovery. These alternative pinmux settings can be + * described in the device tree by a separate pinctrl state "gpio". If + * this is missing this is not a big problem, the only implication is + * that we can't do bus recovery. + */ +static int lpi2c_imx_init_recovery_info(struct lpi2c_imx_struct *lpi2c_imx, + struct platform_device *pdev) +{ + struct i2c_bus_recovery_info *rinfo = &lpi2c_imx->rinfo; + + lpi2c_imx->pinctrl = devm_pinctrl_get(&pdev->dev); + if (!lpi2c_imx->pinctrl || IS_ERR(lpi2c_imx->pinctrl)) { + dev_info(&pdev->dev, "can't get pinctrl, bus recovery not supported\n"); + return PTR_ERR(lpi2c_imx->pinctrl); + } + + lpi2c_imx->pinctrl_pins_default = pinctrl_lookup_state(lpi2c_imx->pinctrl, + PINCTRL_STATE_DEFAULT); + lpi2c_imx->pinctrl_pins_gpio = pinctrl_lookup_state(lpi2c_imx->pinctrl, + "gpio"); + rinfo->sda_gpiod = devm_gpiod_get(&pdev->dev, "sda", GPIOD_IN); + rinfo->scl_gpiod = devm_gpiod_get(&pdev->dev, "scl", GPIOD_OUT_HIGH_OPEN_DRAIN); + + if (PTR_ERR(rinfo->sda_gpiod) == -EPROBE_DEFER || + PTR_ERR(rinfo->scl_gpiod) == -EPROBE_DEFER) { + return -EPROBE_DEFER; + } else if (IS_ERR(rinfo->sda_gpiod) || + IS_ERR(rinfo->scl_gpiod) || + IS_ERR(lpi2c_imx->pinctrl_pins_default) || + IS_ERR(lpi2c_imx->pinctrl_pins_gpio)) { + dev_dbg(&pdev->dev, "recovery information incomplete\n"); + return 0; + } + + dev_info(&pdev->dev, "using scl%s for recovery\n", + rinfo->sda_gpiod ? ",sda" : ""); + + rinfo->prepare_recovery = lpi2c_imx_prepare_recovery; + rinfo->unprepare_recovery = lpi2c_imx_unprepare_recovery; + rinfo->recover_bus = i2c_generic_scl_recovery; + lpi2c_imx->adapter.bus_recovery_info = rinfo; + + return 0; +} + static u32 lpi2c_imx_func(struct i2c_adapter *adapter) { return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | @@ -607,6 +684,12 @@ static int lpi2c_imx_probe(struct platform_device *pdev) pm_runtime_put(&pdev->dev); + /* Init optional bus recovery function */ + ret = lpi2c_imx_init_recovery_info(lpi2c_imx, pdev); + /* Give it another chance if pinctrl used is not ready yet */ + if (ret == -EPROBE_DEFER) + goto rpm_disable; + ret = i2c_add_adapter(&lpi2c_imx->adapter); if (ret) goto rpm_disable;
Add bus recovery feature for LPI2C. Need add gpio pinctrl, scl-gpios and sda-gpios configuration in dts. Signed-off-by: Clark Wang <xiaoning.wang@nxp.com> --- drivers/i2c/busses/i2c-imx-lpi2c.c | 83 ++++++++++++++++++++++++++++++ 1 file changed, 83 insertions(+)