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authorRohith Seelaboyina <rseelaboyina@nvidia.com>2016-06-22 17:17:19 +0530
committerThierry Reding <thierry.reding@gmail.com>2016-07-11 12:49:31 +0200
commit5dfbd2bd5439f1ada5ddaa3883e9e038de5d2abe (patch)
tree2a7d98e034a4e9d7f1194ad9f379de6597b44d0c /drivers/pwm
parent4f57f5a01fcb4ec9d98e274837c0cd853d447da3 (diff)
pwm: tegra: Add support for reset control
Add reset control of the PWM controller to reset it before accessing the PWM register. Signed-off-by: Rohith Seelaboyina <rseelaboyina@nvidia.com> Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Diffstat (limited to 'drivers/pwm')
-rw-r--r--drivers/pwm/pwm-tegra.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-tegra.c b/drivers/pwm/pwm-tegra.c
index 3cbb32d8064f..097658e0751b 100644
--- a/drivers/pwm/pwm-tegra.c
+++ b/drivers/pwm/pwm-tegra.c
@@ -29,6 +29,7 @@
#include <linux/pwm.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
+#include <linux/reset.h>
#define PWM_ENABLE (1 << 31)
#define PWM_DUTY_WIDTH 8
@@ -41,6 +42,7 @@ struct tegra_pwm_chip {
struct device *dev;
struct clk *clk;
+ struct reset_control*rst;
void __iomem *regs;
};
@@ -187,6 +189,15 @@ static int tegra_pwm_probe(struct platform_device *pdev)
if (IS_ERR(pwm->clk))
return PTR_ERR(pwm->clk);
+ pwm->rst = devm_reset_control_get(&pdev->dev, "pwm");
+ if (IS_ERR(pwm->rst)) {
+ ret = PTR_ERR(pwm->rst);
+ dev_err(&pdev->dev, "Reset control is not found: %d\n", ret);
+ return ret;
+ }
+
+ reset_control_deassert(pwm->rst);
+
pwm->chip.dev = &pdev->dev;
pwm->chip.ops = &tegra_pwm_ops;
pwm->chip.base = -1;
@@ -195,6 +206,7 @@ static int tegra_pwm_probe(struct platform_device *pdev)
ret = pwmchip_add(&pwm->chip);
if (ret < 0) {
dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
+ reset_control_assert(pwm->rst);
return ret;
}
@@ -205,10 +217,15 @@ static int tegra_pwm_remove(struct platform_device *pdev)
{
struct tegra_pwm_chip *pc = platform_get_drvdata(pdev);
unsigned int i;
+ int err;
if (WARN_ON(!pc))
return -ENODEV;
+ err = clk_prepare_enable(pc->clk);
+ if (err < 0)
+ return err;
+
for (i = 0; i < pc->chip.npwm; i++) {
struct pwm_device *pwm = &pc->chip.pwms[i];
@@ -221,6 +238,9 @@ static int tegra_pwm_remove(struct platform_device *pdev)
clk_disable_unprepare(pc->clk);
}
+ reset_control_assert(pc->rst);
+ clk_disable_unprepare(pc->clk);
+
return pwmchip_remove(&pc->chip);
}