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Subject[PATCH v3 2/2] hwmon: (aspeed-pwm-tacho) Deassert reset in probe
Date
The ASPEED SoC must deassert a reset in order to use the PWM/tach
peripheral.

Signed-off-by: Joel Stanley <joel@jms.id.au>
---
drivers/hwmon/aspeed-pwm-tacho.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)

diff --git a/drivers/hwmon/aspeed-pwm-tacho.c b/drivers/hwmon/aspeed-pwm-tacho.c
index 63a95e23ca81..693a3d53cab5 100644
--- a/drivers/hwmon/aspeed-pwm-tacho.c
+++ b/drivers/hwmon/aspeed-pwm-tacho.c
@@ -19,6 +19,7 @@
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
+#include <linux/reset.h>
#include <linux/sysfs.h>
#include <linux/thermal.h>

@@ -181,6 +182,7 @@ struct aspeed_cooling_device {

struct aspeed_pwm_tacho_data {
struct regmap *regmap;
+ struct reset_control *rst;
unsigned long clk_freq;
bool pwm_present[8];
bool fan_tach_present[16];
@@ -905,6 +907,13 @@ static int aspeed_create_fan(struct device *dev,
return 0;
}

+static void aspeed_pwm_tacho_remove(void *data)
+{
+ struct aspeed_pwm_tacho_data *priv = data;
+
+ reset_control_assert(priv->rst);
+}
+
static int aspeed_pwm_tacho_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -931,6 +940,19 @@ static int aspeed_pwm_tacho_probe(struct platform_device *pdev)
&aspeed_pwm_tacho_regmap_config);
if (IS_ERR(priv->regmap))
return PTR_ERR(priv->regmap);
+
+ priv->rst = devm_reset_control_get_exclusive(dev, NULL);
+ if (IS_ERR(priv->rst)) {
+ dev_err(dev,
+ "missing or invalid reset controller device tree entry");
+ return PTR_ERR(priv->rst);
+ }
+ reset_control_deassert(priv->rst);
+
+ ret = devm_add_action_or_reset(dev, aspeed_pwm_tacho_remove, priv);
+ if (ret)
+ return ret;
+
regmap_write(priv->regmap, ASPEED_PTCR_TACH_SOURCE, 0);
regmap_write(priv->regmap, ASPEED_PTCR_TACH_SOURCE_EXT, 0);

--
2.15.1
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