| Message ID | 1444809643-25329-1-git-send-email-b54642@freescale.com |
|---|---|
| State | Superseded |
| Headers | show |
On Wed, Oct 14, 2015 at 04:00:43PM +0800, Gao Pan wrote: > Implement bus recovery methods for i2c-imx so we can recover from > situations where SCL/SDA are stuck low. > > Once i2c bus SCL/SDA are stuck low during transfer, config the i2c > pinctrl to gpio mode by calling pinctrl sleep set function, and then > use GPIO to emulate the i2c protocol to send nine dummy clock to recover > i2c device. After recovery, set i2c pinctrl to default group setting. > > Signed-off-by: Fugang Duan <B38611@freescale.com> > Signed-off-by: Gao Pan <b54642@freescale.com> > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> > --- > V2: > As Uwe Kleine-König's suggestion, the version do below changes: > -replace of_get_named_gpio() with devm_gpiod_get_optional() > -move gpio_direction_input() and gpio_direction_output() call to the > prepare callback > -use 0 and 1 as return value for the get_scl and get_sda callbacks > > V3: > -replace "...-gpio" with "...-gpios" in i2c binding doc > -document the requirement of using sleep state to configure > the pins as gpio in i2c binding doc > -remove i2c_recover_bus() in i2c_imx_trx_complete() > -use GPIOD_OUT_HIGH as the parameter of devm_gpiod_get_optional to > config the gpios as output high > -add error disposal as devm_gpiod_get_optional meets error > > V4: > -remove include <linux/of_gpio.h> > -call i2c_recover_bus under the condition of the existing of > both sda and scl. Drop the sda and scl check in i2c_imx_get_scl, > i2c_imx_get_sda, i2c_imx_set_scl, i2c_imx_prepare_recovery and > i2c_imx_prepare_recovery > -use GPIOD_OUT_IN as the parameter of devm_gpiod_get_optional > -remove documenting the requirement of using sleep state to configure > the pins as gpio in i2c binding doc > > V5: > -introduce a dedicated gpio state for bus recovery. > -assign adapter.bus_recovery_info after the two gpios were aquired successfully > > V6: > -assign adapter.bus_recovery_info under the condition that gpios are acquired successfully > -not try the recovery when pinctrl_lookup_state returns an error > > V7: > -execute the bus recovery once in a transfer, when the controller fails to start > -use i2c_generic_gpio_recovery() to handle the bus recovery with gpios > > Documentation/devicetree/bindings/i2c/i2c-imx.txt | 9 +++ > drivers/i2c/busses/i2c-imx.c | 84 +++++++++++++++++++++-- > 2 files changed, 87 insertions(+), 6 deletions(-) > > diff --git a/Documentation/devicetree/bindings/i2c/i2c-imx.txt b/Documentation/devicetree/bindings/i2c/i2c-imx.txt > index ce4311d..eab5836 100644 > --- a/Documentation/devicetree/bindings/i2c/i2c-imx.txt > +++ b/Documentation/devicetree/bindings/i2c/i2c-imx.txt > @@ -14,6 +14,10 @@ Optional properties: > The absence of the propoerty indicates the default frequency 100 kHz. > - dmas: A list of two dma specifiers, one for each entry in dma-names. > - dma-names: should contain "tx" and "rx". > +- scl-gpios: specify the gpio related to SCL pin > +- sda-gpios: specify the gpio related to SDA pin > +- pinctrl: add extra pinctrl to configure i2c pins to gpio function for i2c > + bus recovery, call it "gpio" state > > Examples: > > @@ -37,4 +41,9 @@ i2c0: i2c@40066000 { /* i2c0 on vf610 */ > dmas = <&edma0 0 50>, > <&edma0 0 51>; > dma-names = "rx","tx"; > + pinctrl-names = "default", "gpio"; > + pinctrl-0 = <&pinctrl_i2c1>; > + pinctrl-1 = <&pinctrl_i2c1_gpio>; > + scl-gpios = <&gpio5 26 GPIO_ACTIVE_HIGH>; > + sda-gpios = <&gpio5 27 GPIO_ACTIVE_HIGH>; > }; > diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c > index 91bdf28..c3a0d43 100644 > --- a/drivers/i2c/busses/i2c-imx.c > +++ b/drivers/i2c/busses/i2c-imx.c > @@ -49,6 +49,7 @@ > #include <linux/of.h> > #include <linux/of_device.h> > #include <linux/of_dma.h> > +#include <linux/of_gpio.h> > #include <linux/platform_data/i2c-imx.h> > #include <linux/platform_device.h> > #include <linux/sched.h> > @@ -64,6 +65,8 @@ > /* Default value */ > #define IMX_I2C_BIT_RATE 100000 /* 100kHz */ > > +#define I2C_PINCTRL_STATE_GPIO "gpio" This is unused, please remove. > static u32 i2c_imx_func(struct i2c_adapter *adapter) > { > return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL > @@ -1011,12 +1075,12 @@ static int i2c_imx_probe(struct platform_device *pdev) > > /* Setup i2c_imx driver structure */ > strlcpy(i2c_imx->adapter.name, pdev->name, sizeof(i2c_imx->adapter.name)); > - i2c_imx->adapter.owner = THIS_MODULE; > - i2c_imx->adapter.algo = &i2c_imx_algo; > - i2c_imx->adapter.dev.parent = &pdev->dev; > - i2c_imx->adapter.nr = pdev->id; > - i2c_imx->adapter.dev.of_node = pdev->dev.of_node; > - i2c_imx->base = base; > + i2c_imx->adapter.owner = THIS_MODULE; > + i2c_imx->adapter.algo = &i2c_imx_algo; > + i2c_imx->adapter.dev.parent = &pdev->dev; > + i2c_imx->adapter.nr = pdev->id; > + i2c_imx->adapter.dev.of_node = pdev->dev.of_node; > + i2c_imx->base = base; unrelated whitespace changes. Please drop this. Sascha
diff --git a/Documentation/devicetree/bindings/i2c/i2c-imx.txt b/Documentation/devicetree/bindings/i2c/i2c-imx.txt index ce4311d..eab5836 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-imx.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-imx.txt @@ -14,6 +14,10 @@ Optional properties: The absence of the propoerty indicates the default frequency 100 kHz. - dmas: A list of two dma specifiers, one for each entry in dma-names. - dma-names: should contain "tx" and "rx". +- scl-gpios: specify the gpio related to SCL pin +- sda-gpios: specify the gpio related to SDA pin +- pinctrl: add extra pinctrl to configure i2c pins to gpio function for i2c + bus recovery, call it "gpio" state Examples: @@ -37,4 +41,9 @@ i2c0: i2c@40066000 { /* i2c0 on vf610 */ dmas = <&edma0 0 50>, <&edma0 0 51>; dma-names = "rx","tx"; + pinctrl-names = "default", "gpio"; + pinctrl-0 = <&pinctrl_i2c1>; + pinctrl-1 = <&pinctrl_i2c1_gpio>; + scl-gpios = <&gpio5 26 GPIO_ACTIVE_HIGH>; + sda-gpios = <&gpio5 27 GPIO_ACTIVE_HIGH>; }; diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index 91bdf28..c3a0d43 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -49,6 +49,7 @@ #include <linux/of.h> #include <linux/of_device.h> #include <linux/of_dma.h> +#include <linux/of_gpio.h> #include <linux/platform_data/i2c-imx.h> #include <linux/platform_device.h> #include <linux/sched.h> @@ -64,6 +65,8 @@ /* Default value */ #define IMX_I2C_BIT_RATE 100000 /* 100kHz */ +#define I2C_PINCTRL_STATE_GPIO "gpio" + /* * Enable DMA if transfer byte size is bigger than this threshold. * As the hardware request, it must bigger than 4 bytes.\ @@ -210,6 +213,11 @@ struct imx_i2c_struct { unsigned int cur_clk; unsigned int bitrate; const struct imx_i2c_hwdata *hwdata; + struct i2c_bus_recovery_info rinfo; + + struct pinctrl *pinctrl; + struct pinctrl_state *pinctrl_pins_default; + struct pinctrl_state *pinctrl_pins_gpio; struct imx_i2c_dma *dma; }; @@ -899,6 +907,13 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter, /* Start I2C transfer */ result = i2c_imx_start(i2c_imx); + if (result) { + if (i2c_imx->adapter.bus_recovery_info) { + i2c_recover_bus(&i2c_imx->adapter); + result = i2c_imx_start(i2c_imx); + } + } + if (result) goto fail0; @@ -963,6 +978,55 @@ out: return (result < 0) ? result : num; } +static void i2c_imx_prepare_recovery(struct i2c_adapter *adap) +{ + struct imx_i2c_struct *i2c_imx; + + i2c_imx = container_of(adap, struct imx_i2c_struct, adapter); + + pinctrl_select_state(i2c_imx->pinctrl, i2c_imx->pinctrl_pins_gpio); +} + +static void i2c_imx_unprepare_recovery(struct i2c_adapter *adap) +{ + struct imx_i2c_struct *i2c_imx; + + i2c_imx = container_of(adap, struct imx_i2c_struct, adapter); + + pinctrl_select_state(i2c_imx->pinctrl, i2c_imx->pinctrl_pins_default); +} + +static void i2c_imx_init_recovery_info(struct imx_i2c_struct *i2c_imx, + struct platform_device *pdev) +{ + struct i2c_bus_recovery_info *rinfo = &i2c_imx->rinfo; + + i2c_imx->pinctrl_pins_default = pinctrl_lookup_state(i2c_imx->pinctrl, + PINCTRL_STATE_DEFAULT); + i2c_imx->pinctrl_pins_gpio = pinctrl_lookup_state(i2c_imx->pinctrl, + "gpio"); + rinfo->sda_gpio = of_get_named_gpio_flags(pdev->dev.of_node, + "sda-gpios", 0, NULL); + rinfo->scl_gpio = of_get_named_gpio_flags(pdev->dev.of_node, + "scl-gpios", 0, NULL); + + if (!gpio_is_valid(rinfo->sda_gpio) || + !gpio_is_valid(rinfo->scl_gpio) || + IS_ERR(i2c_imx->pinctrl_pins_default) || + IS_ERR(i2c_imx->pinctrl_pins_gpio)) { + dev_dbg(&pdev->dev, "recovery information incomplete\n"); + return; + } + + dev_dbg(&pdev->dev, "using scl-gpio %d and sda-gpio %d for recovery\n", + rinfo->sda_gpio, rinfo->scl_gpio); + + rinfo->prepare_recovery = i2c_imx_prepare_recovery; + rinfo->unprepare_recovery = i2c_imx_unprepare_recovery; + rinfo->recover_bus = i2c_generic_gpio_recovery; + i2c_imx->adapter.bus_recovery_info = rinfo; +} + static u32 i2c_imx_func(struct i2c_adapter *adapter) { return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL @@ -1011,12 +1075,12 @@ static int i2c_imx_probe(struct platform_device *pdev) /* Setup i2c_imx driver structure */ strlcpy(i2c_imx->adapter.name, pdev->name, sizeof(i2c_imx->adapter.name)); - i2c_imx->adapter.owner = THIS_MODULE; - i2c_imx->adapter.algo = &i2c_imx_algo; - i2c_imx->adapter.dev.parent = &pdev->dev; - i2c_imx->adapter.nr = pdev->id; - i2c_imx->adapter.dev.of_node = pdev->dev.of_node; - i2c_imx->base = base; + i2c_imx->adapter.owner = THIS_MODULE; + i2c_imx->adapter.algo = &i2c_imx_algo; + i2c_imx->adapter.dev.parent = &pdev->dev; + i2c_imx->adapter.nr = pdev->id; + i2c_imx->adapter.dev.of_node = pdev->dev.of_node; + i2c_imx->base = base; /* Get I2C clock */ i2c_imx->clk = devm_clk_get(&pdev->dev, NULL); @@ -1031,6 +1095,12 @@ static int i2c_imx_probe(struct platform_device *pdev) return ret; } + i2c_imx->pinctrl = devm_pinctrl_get(&pdev->dev); + if (IS_ERR(i2c_imx->pinctrl)) { + ret = PTR_ERR(i2c_imx->pinctrl); + goto clk_disable; + } + /* Request IRQ */ ret = devm_request_irq(&pdev->dev, irq, i2c_imx_isr, 0, pdev->name, i2c_imx); @@ -1045,6 +1115,8 @@ static int i2c_imx_probe(struct platform_device *pdev) /* Set up adapter data */ i2c_set_adapdata(&i2c_imx->adapter, i2c_imx); + i2c_imx_init_recovery_info(i2c_imx, pdev); + /* Set up platform driver data */ platform_set_drvdata(pdev, i2c_imx);