diff options
| author | Zhangfei Gao <zhangfei.gao@linaro.org> | 2016-12-27 22:22:40 +0800 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2017-03-08 18:15:18 +0100 |
| commit | ab809fd81fde3d416f8656d8f814a0777fb9b65e (patch) | |
| tree | 18784d3b6c72ae0f3f87a1820e2c68fa5f78ad67 /drivers/i2c | |
| parent | 3b0277f198ac928f323c42e180680d2f79aa980d (diff) | |
| download | lwn-ab809fd81fde3d416f8656d8f814a0777fb9b65e.tar.gz lwn-ab809fd81fde3d416f8656d8f814a0777fb9b65e.zip | |
i2c: designware: add reset interface
Some platforms like hi3660 need do reset first to allow accessing registers
Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Ramiro Oliveira <ramiro.oliveira@synopsys.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-designware-core.h | 1 | ||||
| -rw-r--r-- | drivers/i2c/busses/i2c-designware-platdrv.c | 28 |
2 files changed, 25 insertions, 4 deletions
diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h index c1db3a5a340f..d9aaf1790e0e 100644 --- a/drivers/i2c/busses/i2c-designware-core.h +++ b/drivers/i2c/busses/i2c-designware-core.h @@ -88,6 +88,7 @@ struct dw_i2c_dev { void __iomem *base; struct completion cmd_complete; struct clk *clk; + struct reset_control *rst; u32 (*get_clk_rate_khz) (struct dw_i2c_dev *dev); struct dw_pci_controller *controller; int cmd_err; diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c index 6ce431323125..79c4b4ea0539 100644 --- a/drivers/i2c/busses/i2c-designware-platdrv.c +++ b/drivers/i2c/busses/i2c-designware-platdrv.c @@ -38,6 +38,7 @@ #include <linux/pm_runtime.h> #include <linux/property.h> #include <linux/io.h> +#include <linux/reset.h> #include <linux/slab.h> #include <linux/acpi.h> #include <linux/platform_data/i2c-designware.h> @@ -199,6 +200,14 @@ static int dw_i2c_plat_probe(struct platform_device *pdev) dev->irq = irq; platform_set_drvdata(pdev, dev); + dev->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL); + if (IS_ERR(dev->rst)) { + if (PTR_ERR(dev->rst) == -EPROBE_DEFER) + return -EPROBE_DEFER; + } else { + reset_control_deassert(dev->rst); + } + if (pdata) { dev->clk_freq = pdata->i2c_scl_freq; } else { @@ -235,12 +244,13 @@ static int dw_i2c_plat_probe(struct platform_device *pdev) && dev->clk_freq != 1000000 && dev->clk_freq != 3400000) { dev_err(&pdev->dev, "Only 100kHz, 400kHz, 1MHz and 3.4MHz supported"); - return -EINVAL; + r = -EINVAL; + goto exit_reset; } r = i2c_dw_eval_lock_support(dev); if (r) - return r; + goto exit_reset; dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY; @@ -286,10 +296,18 @@ static int dw_i2c_plat_probe(struct platform_device *pdev) } r = i2c_dw_probe(dev); - if (r && !dev->pm_runtime_disabled) - pm_runtime_disable(&pdev->dev); + if (r) + goto exit_probe; return r; + +exit_probe: + if (!dev->pm_runtime_disabled) + pm_runtime_disable(&pdev->dev); +exit_reset: + if (!IS_ERR_OR_NULL(dev->rst)) + reset_control_assert(dev->rst); + return r; } static int dw_i2c_plat_remove(struct platform_device *pdev) @@ -306,6 +324,8 @@ static int dw_i2c_plat_remove(struct platform_device *pdev) pm_runtime_put_sync(&pdev->dev); if (!dev->pm_runtime_disabled) pm_runtime_disable(&pdev->dev); + if (!IS_ERR_OR_NULL(dev->rst)) + reset_control_assert(dev->rst); return 0; } |