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Message-ID: <1448444485-4857-1-git-send-email-jszhang@marvell.com>
Date: Wed, 25 Nov 2015 17:41:25 +0800
From: Jisheng Zhang <jszhang@...vell.com>
To: <thierry.reding@...il.com>, <sebastian.hesselbarth@...il.com>,
<antoine.tenart@...e-electrons.com>
CC: <linux-pwm@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<linux-arm-kernel@...ts.infradead.org>,
Jisheng Zhang <jszhang@...vell.com>
Subject: [PATCH v2] pwm: berlin: Add PM support
This patch adds S2R support for berlin pwm driver.
Signed-off-by: Jisheng Zhang <jszhang@...vell.com>
---
Since v1:
- implement .request and .free hooks, allocate/free the channel in
berlin_pwm_request/berlin_pwm_free. Then use pwm_get_chip_data in
suspend/resume implementation.
- s/int/unsigned int
- check return value of clk_prepare_enable
- remoev BERLIN_PWM_PM_OPS macro
drivers/pwm/pwm-berlin.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 89 insertions(+), 1 deletion(-)
diff --git a/drivers/pwm/pwm-berlin.c b/drivers/pwm/pwm-berlin.c
index 6510812..a66b9ff 100644
--- a/drivers/pwm/pwm-berlin.c
+++ b/drivers/pwm/pwm-berlin.c
@@ -16,6 +16,7 @@
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
+#include <linux/slab.h>
#define BERLIN_PWM_EN 0x0
#define BERLIN_PWM_ENABLE BIT(0)
@@ -27,6 +28,15 @@
#define BERLIN_PWM_TCNT 0xc
#define BERLIN_PWM_MAX_TCNT 65535
+#define NUM_PWM_CHANNEL 4 /* berlin PWM channels */
+
+struct berlin_pwm_channel {
+ u32 enable;
+ u32 ctrl;
+ u32 duty;
+ u32 tcnt;
+};
+
struct berlin_pwm_chip {
struct pwm_chip chip;
struct clk *clk;
@@ -55,6 +65,28 @@ static inline void berlin_pwm_writel(struct berlin_pwm_chip *chip,
writel_relaxed(value, chip->base + channel * 0x10 + offset);
}
+static int berlin_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm_dev)
+{
+ struct berlin_pwm_channel *chan;
+
+ if (pwm_dev->hwpwm >= NUM_PWM_CHANNEL)
+ return -EINVAL;
+
+ chan = kzalloc(sizeof(*chan), GFP_KERNEL);
+ if (!chan)
+ return -ENOMEM;
+
+ return pwm_set_chip_data(pwm_dev, chan);
+}
+
+static void berlin_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm_dev)
+{
+ struct berlin_pwm_channel *chan = pwm_get_chip_data(pwm_dev);
+
+ kfree(chan);
+ pwm_set_chip_data(pwm_dev, NULL);
+}
+
static int berlin_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm_dev,
int duty_ns, int period_ns)
{
@@ -137,6 +169,8 @@ static void berlin_pwm_disable(struct pwm_chip *chip,
}
static const struct pwm_ops berlin_pwm_ops = {
+ .request = berlin_pwm_request,
+ .free = berlin_pwm_free,
.config = berlin_pwm_config,
.set_polarity = berlin_pwm_set_polarity,
.enable = berlin_pwm_enable,
@@ -176,7 +210,7 @@ static int berlin_pwm_probe(struct platform_device *pdev)
pwm->chip.dev = &pdev->dev;
pwm->chip.ops = &berlin_pwm_ops;
pwm->chip.base = -1;
- pwm->chip.npwm = 4;
+ pwm->chip.npwm = NUM_PWM_CHANNEL;
pwm->chip.can_sleep = true;
pwm->chip.of_xlate = of_pwm_xlate_with_flags;
pwm->chip.of_pwm_n_cells = 3;
@@ -204,12 +238,66 @@ static int berlin_pwm_remove(struct platform_device *pdev)
return ret;
}
+#ifdef CONFIG_PM_SLEEP
+static int berlin_pwm_suspend(struct device *dev)
+{
+ unsigned int i;
+ struct berlin_pwm_chip *pwm = dev_get_drvdata(dev);
+
+ for (i = 0; i < pwm->chip.npwm; i++) {
+ struct pwm_device *pwm_dev = &pwm->chip.pwms[i];
+ struct berlin_pwm_channel *chan = pwm_get_chip_data(pwm_dev);
+
+ if (!chan)
+ continue;
+
+ chan->enable = berlin_pwm_readl(pwm, i, BERLIN_PWM_ENABLE);
+ chan->ctrl = berlin_pwm_readl(pwm, i, BERLIN_PWM_CONTROL);
+ chan->duty = berlin_pwm_readl(pwm, i, BERLIN_PWM_DUTY);
+ chan->tcnt = berlin_pwm_readl(pwm, i, BERLIN_PWM_TCNT);
+ }
+ clk_disable_unprepare(pwm->clk);
+
+ return 0;
+}
+
+static int berlin_pwm_resume(struct device *dev)
+{
+ int ret;
+ unsigned int i;
+ struct berlin_pwm_chip *pwm = dev_get_drvdata(dev);
+
+ ret = clk_prepare_enable(pwm->clk);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < pwm->chip.npwm; i++) {
+ struct pwm_device *pwm_dev = &pwm->chip.pwms[i];
+ struct berlin_pwm_channel *chan = pwm_get_chip_data(pwm_dev);
+
+ if (!chan)
+ continue;
+
+ berlin_pwm_writel(pwm, i, chan->ctrl, BERLIN_PWM_CONTROL);
+ berlin_pwm_writel(pwm, i, chan->duty, BERLIN_PWM_DUTY);
+ berlin_pwm_writel(pwm, i, chan->tcnt, BERLIN_PWM_TCNT);
+ berlin_pwm_writel(pwm, i, chan->enable, BERLIN_PWM_ENABLE);
+ }
+
+ return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(berlin_pwm_pm_ops, berlin_pwm_suspend,
+ berlin_pwm_resume);
+
static struct platform_driver berlin_pwm_driver = {
.probe = berlin_pwm_probe,
.remove = berlin_pwm_remove,
.driver = {
.name = "berlin-pwm",
.of_match_table = berlin_pwm_match,
+ .pm = &berlin_pwm_pm_ops,
},
};
module_platform_driver(berlin_pwm_driver);
--
2.6.2
--
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