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i2c: designware: add reset interface

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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>
This commit is contained in:
Zhangfei Gao 2016-12-27 22:22:40 +08:00 committed by Wolfram Sang
parent 3b0277f198
commit ab809fd81f
2 changed files with 25 additions and 4 deletions
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1
drivers/i2c/busses/i2c-designware-core.h
View file

@ -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;

28
drivers/i2c/busses/i2c-designware-platdrv.c
View file

@ -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;
}