From: Philip Avinash <avinashphilip@ti.com>
To: thierry.reding@avionic-design.de
Cc: linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org,
nsekhar@ti.com, gururaja.hebbar@ti.com,
Philip Avinash <avinashphilip@ti.com>
Subject: [PATCH v2 2/2] pwm: pwm-tiecap: Low power sleep support
Date: Thu, 17 Jan 2013 14:50:03 +0530 [thread overview]
Message-ID: <1358414403-13431-3-git-send-email-avinashphilip@ti.com> (raw)
In-Reply-To: <1358414403-13431-1-git-send-email-avinashphilip@ti.com>
In low power modes of AM33XX platforms, peripherals power is cut off.
This patch supports low power sleep transition support for ECAP driver.
Signed-off-by: Philip Avinash <avinashphilip@ti.com>
---
Changes since v1:
- check the enabled status of pwm device for handling module
enable/disable on resume/suspend
drivers/pwm/pwm-tiecap.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 53 insertions(+)
diff --git a/drivers/pwm/pwm-tiecap.c b/drivers/pwm/pwm-tiecap.c
index 5cf016d..05b676d 100644
--- a/drivers/pwm/pwm-tiecap.c
+++ b/drivers/pwm/pwm-tiecap.c
@@ -41,10 +41,17 @@
#define ECCTL2_SYNC_SEL_DISA (BIT(7) | BIT(6))
#define ECCTL2_TSCTR_FREERUN BIT(4)
+struct ecap_context {
+ u32 cap3;
+ u32 cap4;
+ u16 ecctl2;
+};
+
struct ecap_pwm_chip {
struct pwm_chip chip;
unsigned int clk_rate;
void __iomem *mmio_base;
+ struct ecap_context ctx;
};
static inline struct ecap_pwm_chip *to_ecap_pwm_chip(struct pwm_chip *chip)
@@ -288,11 +295,57 @@ static int ecap_pwm_remove(struct platform_device *pdev)
return pwmchip_remove(&pc->chip);
}
+void ecap_pwm_save_context(struct ecap_pwm_chip *pc)
+{
+ pm_runtime_get_sync(pc->chip.dev);
+ pc->ctx.ecctl2 = readw(pc->mmio_base + ECCTL2);
+ pc->ctx.cap4 = readl(pc->mmio_base + CAP4);
+ pc->ctx.cap3 = readl(pc->mmio_base + CAP3);
+ pm_runtime_put_sync(pc->chip.dev);
+}
+
+void ecap_pwm_restore_context(struct ecap_pwm_chip *pc)
+{
+ writel(pc->ctx.cap3, pc->mmio_base + CAP3);
+ writel(pc->ctx.cap4, pc->mmio_base + CAP4);
+ writew(pc->ctx.ecctl2, pc->mmio_base + ECCTL2);
+}
+
+static int ecap_pwm_suspend(struct device *dev)
+{
+ struct ecap_pwm_chip *pc = dev_get_drvdata(dev);
+ struct pwm_device *pwm = pc->chip.pwms;
+
+ ecap_pwm_save_context(pc);
+
+ /* Disable explicitly if PWM is running */
+ if (test_bit(PWMF_ENABLED, &pwm->flags))
+ pm_runtime_put_sync(dev);
+
+ return 0;
+}
+
+static int ecap_pwm_resume(struct device *dev)
+{
+ struct ecap_pwm_chip *pc = dev_get_drvdata(dev);
+ struct pwm_device *pwm = pc->chip.pwms;
+
+ /* Enable explicitly if PWM was running */
+ if (test_bit(PWMF_ENABLED, &pwm->flags))
+ pm_runtime_get_sync(dev);
+
+ ecap_pwm_restore_context(pc);
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(ecap_pwm_pm_ops, ecap_pwm_suspend, ecap_pwm_resume);
+
static struct platform_driver ecap_pwm_driver = {
.driver = {
.name = "ecap",
.owner = THIS_MODULE,
.of_match_table = ecap_of_match,
+ .pm = &ecap_pwm_pm_ops,
},
.probe = ecap_pwm_probe,
.remove = ecap_pwm_remove,
--
1.7.9.5
next prev parent reply other threads:[~2013-01-17 9:20 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-17 9:20 [PATCH v2 0/2] LOW power sleep support for TI PWM submodules Philip Avinash
2013-01-17 9:20 ` [PATCH v2 1/2] pwm: pwm-tiehrpwm: Low power sleep support Philip Avinash
2013-01-17 15:59 ` Thierry Reding
2013-01-18 4:19 ` Philip, Avinash
2013-01-17 9:20 ` Philip Avinash [this message]
2013-01-17 15:59 ` [PATCH v2 2/2] pwm: pwm-tiecap: " Thierry Reding
2013-01-18 4:19 ` Philip, Avinash
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