diff options
| -rw-r--r-- | Documentation/devicetree/bindings/i2c/i2c-imx.txt | 9 | ||||
| -rw-r--r-- | drivers/i2c/busses/i2c-imx.c | 71 |
2 files changed, 80 insertions, 0 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 785aa67..8d46e74 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> @@ -207,6 +208,11 @@ 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; }; @@ -896,6 +902,13 @@ 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; @@ -956,6 +969,55 @@ fail0: 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 @@ -1023,6 +1085,13 @@ static int i2c_imx_probe(struct platform_device *pdev) dev_err(&pdev->dev, "can't enable I2C clock\n"); 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); @@ -1056,6 +1125,8 @@ static int i2c_imx_probe(struct platform_device *pdev) goto clk_disable; } + i2c_imx_init_recovery_info(i2c_imx, pdev); + /* Set up platform driver data */ platform_set_drvdata(pdev, i2c_imx); clk_disable_unprepare(i2c_imx->clk); |