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authorZhangfei Gao <zhangfei.gao@linaro.org>2016-12-27 17:22:40 +0300
committerWolfram Sang <wsa@the-dreams.de>2017-03-08 20:15:18 +0300
commitab809fd81fde3d416f8656d8f814a0777fb9b65e (patch)
tree18784d3b6c72ae0f3f87a1820e2c68fa5f78ad67 /drivers/i2c/busses/i2c-designware-platdrv.c
parent3b0277f198ac928f323c42e180680d2f79aa980d (diff)
downloadlinux-ab809fd81fde3d416f8656d8f814a0777fb9b65e.tar.xz
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/busses/i2c-designware-platdrv.c')
-rw-r--r--drivers/i2c/busses/i2c-designware-platdrv.c28
1 files changed, 24 insertions, 4 deletions
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;
}