From fd8961c5ba9e6c841cdf4cc00903316e5bd35180 Mon Sep 17 00:00:00 2001 From: Yang Li Date: Mon, 12 Sep 2016 17:22:30 -0500 Subject: [PATCH] i2c: imx: make bus recovery through pinctrl optional MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Since commit 1c4b6c3bcf30 ("i2c: imx: implement bus recovery") the driver starts to use gpio/pinctrl to support optional bus recovery feature. But pinctrl is not always usable. There are platforms such as ls1021a and ls1043a that don't support pinctrl, and it could just be broken due to old/broken device tree. The patch makes it really optional that the probe function won't bailout on pinctrl problems instead it just disables bus recovery and prints out notification when there is problem with pinctrl. Since pinctrl is only used by bus recovery in this driver, move pinctrl initialization into bus recovery init function to prevent confusion. Signed-off-by: Li Yang Acked-by: Linus Walleij Acked-by: Uwe Kleine-König Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-imx.c | 31 ++++++++++++++++++++++--------- 1 file changed, 22 insertions(+), 9 deletions(-) diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index cb11eee..592a8f2 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -984,11 +984,24 @@ static void i2c_imx_unprepare_recovery(struct i2c_adapter *adap) pinctrl_select_state(i2c_imx->pinctrl, i2c_imx->pinctrl_pins_default); } -static void i2c_imx_init_recovery_info(struct imx_i2c_struct *i2c_imx, +/* + * 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 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 = devm_pinctrl_get(&pdev->dev); + if (!i2c_imx->pinctrl || IS_ERR(i2c_imx->pinctrl)) { + dev_info(&pdev->dev, "can't get pinctrl, bus recovery not supported\n"); + return PTR_ERR(i2c_imx->pinctrl); + } + 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, @@ -1001,7 +1014,7 @@ static void i2c_imx_init_recovery_info(struct imx_i2c_struct *i2c_imx, IS_ERR(i2c_imx->pinctrl_pins_default) || IS_ERR(i2c_imx->pinctrl_pins_gpio)) { dev_dbg(&pdev->dev, "recovery information incomplete\n"); - return; + return 0; } dev_dbg(&pdev->dev, "using scl-gpio %d and sda-gpio %d for recovery\n", @@ -1011,6 +1024,8 @@ static void i2c_imx_init_recovery_info(struct imx_i2c_struct *i2c_imx, rinfo->unprepare_recovery = i2c_imx_unprepare_recovery; rinfo->recover_bus = i2c_generic_gpio_recovery; i2c_imx->adapter.bus_recovery_info = rinfo; + + return 0; } static u32 i2c_imx_func(struct i2c_adapter *adapter) @@ -1081,12 +1096,6 @@ 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); @@ -1125,7 +1134,11 @@ static int i2c_imx_probe(struct platform_device *pdev) i2c_imx, IMX_I2C_I2CR); imx_i2c_write_reg(i2c_imx->hwdata->i2sr_clr_opcode, i2c_imx, IMX_I2C_I2SR); - i2c_imx_init_recovery_info(i2c_imx, pdev); + /* Init optional bus recovery function */ + ret = i2c_imx_init_recovery_info(i2c_imx, pdev); + /* Give it another chance if pinctrl used is not ready yet */ + if (ret == -EPROBE_DEFER) + goto rpm_disable; /* Add I2C adapter */ ret = i2c_add_numbered_adapter(&i2c_imx->adapter); -- 2.7.4