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authorJoel Stanley <joel@jms.id.au>2017-10-31 03:12:03 +0100
committerJonathan Cameron <Jonathan.Cameron@huawei.com>2017-12-02 11:41:15 +0100
commitedf7550a1f93a88be2bf743b5d352b278d1b789c (patch)
tree518f1a1e87a87244af5697d97a3666eb7f6bfe9b /drivers/iio/adc
parentdt-bindings: iio: health: Add MAX30105 support to max30102.txt (diff)
downloadlinux-edf7550a1f93a88be2bf743b5d352b278d1b789c.tar.xz
linux-edf7550a1f93a88be2bf743b5d352b278d1b789c.zip
iio: adc: aspeed: Deassert reset in probe
The ASPEED SoC must deassert a reset in order to use the ADC peripheral. The device tree bindings are updated to document the resets phandle, and the example is updated to match what is expected for both the reset and clock phandle. Note that the bindings should have always had the reset controller, as the hardware is unusable without it. Signed-off-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'drivers/iio/adc')
-rw-r--r--drivers/iio/adc/aspeed_adc.c25
1 files changed, 19 insertions, 6 deletions
diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
index 8a958d5f1905..327a49ba1991 100644
--- a/drivers/iio/adc/aspeed_adc.c
+++ b/drivers/iio/adc/aspeed_adc.c
@@ -17,6 +17,7 @@
#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
+#include <linux/reset.h>
#include <linux/spinlock.h>
#include <linux/types.h>
@@ -53,11 +54,12 @@ struct aspeed_adc_model_data {
};
struct aspeed_adc_data {
- struct device *dev;
- void __iomem *base;
- spinlock_t clk_lock;
- struct clk_hw *clk_prescaler;
- struct clk_hw *clk_scaler;
+ struct device *dev;
+ void __iomem *base;
+ spinlock_t clk_lock;
+ struct clk_hw *clk_prescaler;
+ struct clk_hw *clk_scaler;
+ struct reset_control *rst;
};
#define ASPEED_CHAN(_idx, _data_reg_addr) { \
@@ -217,6 +219,15 @@ static int aspeed_adc_probe(struct platform_device *pdev)
goto scaler_error;
}
+ data->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+ if (IS_ERR(data->rst)) {
+ dev_err(&pdev->dev,
+ "invalid or missing reset controller device tree entry");
+ ret = PTR_ERR(data->rst);
+ goto reset_error;
+ }
+ reset_control_deassert(data->rst);
+
model_data = of_device_get_match_data(&pdev->dev);
if (model_data->wait_init_sequence) {
@@ -263,9 +274,10 @@ iio_register_error:
writel(ASPEED_OPERATION_MODE_POWER_DOWN,
data->base + ASPEED_REG_ENGINE_CONTROL);
clk_disable_unprepare(data->clk_scaler->clk);
+reset_error:
+ reset_control_assert(data->rst);
clk_enable_error:
clk_hw_unregister_divider(data->clk_scaler);
-
scaler_error:
clk_hw_unregister_divider(data->clk_prescaler);
return ret;
@@ -280,6 +292,7 @@ static int aspeed_adc_remove(struct platform_device *pdev)
writel(ASPEED_OPERATION_MODE_POWER_DOWN,
data->base + ASPEED_REG_ENGINE_CONTROL);
clk_disable_unprepare(data->clk_scaler->clk);
+ reset_control_assert(data->rst);
clk_hw_unregister_divider(data->clk_scaler);
clk_hw_unregister_divider(data->clk_prescaler);