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Message-ID: <20170816221715.15027-3-fcooper@ti.com>
Date: Wed, 16 Aug 2017 17:17:14 -0500
From: Franklin S Cooper Jr <fcooper@...com>
To: <wsa@...-dreams.de>, <robh+dt@...nel.org>, <linux@...linux.org.uk>,
<nsekhar@...com>, <linux-i2c@...r.kernel.org>,
<devicetree@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<linux-arm-kernel@...ts.infradead.org>, <grygorii.strashko@...com>,
<vigneshr@...com>
CC: Franklin S Cooper Jr <fcooper@...com>
Subject: [PATCH v2 2/3] i2c: davinci: Add PM Runtime Support
66AK2G has I2C instances that are not apart of the ALWAYS_ON power domain
like other Keystone 2 SoCs and OMAPL138. Therefore, pm_runtime
is required to insure the power domain used by the specific I2C instance is
properly turned on along with its functional clock.
Signed-off-by: Franklin S Cooper Jr <fcooper@...com>
---
Version 2 changes:
Move initial calls to pm runtime autosuspend before pm_runtime_enable
drivers/i2c/busses/i2c-davinci.c | 62 ++++++++++++++++++++++++++++++++++------
1 file changed, 54 insertions(+), 8 deletions(-)
diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index b8c4353..6b1930d 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -36,6 +36,7 @@
#include <linux/gpio.h>
#include <linux/of_device.h>
#include <linux/platform_data/i2c-davinci.h>
+#include <linux/pm_runtime.h>
/* ----- global defines ----------------------------------------------- */
@@ -122,6 +123,9 @@
/* set the SDA GPIO low */
#define DAVINCI_I2C_DCLR_PDCLR1 BIT(1)
+/* timeout for pm runtime autosuspend */
+#define DAVINCI_I2C_PM_TIMEOUT 1000 /* ms */
+
struct davinci_i2c_dev {
struct device *dev;
void __iomem *base;
@@ -541,10 +545,17 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
+ ret = pm_runtime_get_sync(dev->dev);
+ if (ret < 0) {
+ dev_err(dev->dev, "Failed to runtime_get device: %d\n", ret);
+ pm_runtime_put_noidle(dev->dev);
+ return ret;
+ }
+
ret = i2c_davinci_wait_bus_not_busy(dev);
if (ret < 0) {
dev_warn(dev->dev, "timeout waiting for bus ready\n");
- return ret;
+ goto out;
}
for (i = 0; i < num; i++) {
@@ -552,14 +563,19 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
dev_dbg(dev->dev, "%s [%d/%d] ret: %d\n", __func__, i + 1, num,
ret);
if (ret < 0)
- return ret;
+ goto out;
}
+ ret = num;
#ifdef CONFIG_CPU_FREQ
complete(&dev->xfr_complete);
#endif
- return num;
+out:
+ pm_runtime_mark_last_busy(dev->dev);
+ pm_runtime_put_autosuspend(dev->dev);
+
+ return ret;
}
static u32 i2c_davinci_func(struct i2c_adapter *adap)
@@ -599,6 +615,9 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id)
int count = 0;
u16 w;
+ if (pm_runtime_suspended(dev->dev))
+ return IRQ_NONE;
+
while ((stat = davinci_i2c_read_reg(dev, DAVINCI_I2C_IVR_REG))) {
dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat);
if (count++ == 100) {
@@ -802,7 +821,6 @@ static int davinci_i2c_probe(struct platform_device *pdev)
dev->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(dev->clk))
return PTR_ERR(dev->clk);
- clk_prepare_enable(dev->clk);
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
dev->base = devm_ioremap_resource(&pdev->dev, mem);
@@ -811,6 +829,18 @@ static int davinci_i2c_probe(struct platform_device *pdev)
goto err_unuse_clocks;
}
+ pm_runtime_set_autosuspend_delay(dev->dev,
+ DAVINCI_I2C_PM_TIMEOUT);
+ pm_runtime_use_autosuspend(dev->dev);
+
+ pm_runtime_enable(dev->dev);
+
+ r = pm_runtime_get_sync(dev->dev);
+ if (r < 0) {
+ dev_err(dev->dev, "failed to runtime_get device: %d\n", r);
+ goto err_unuse_clocks;
+ }
+
i2c_davinci_init(dev);
r = devm_request_irq(&pdev->dev, dev->irq, i2c_davinci_isr, 0,
@@ -849,10 +879,16 @@ static int davinci_i2c_probe(struct platform_device *pdev)
if (r)
goto err_unuse_clocks;
+ pm_runtime_mark_last_busy(dev->dev);
+ pm_runtime_put_autosuspend(dev->dev);
+
return 0;
err_unuse_clocks:
- clk_disable_unprepare(dev->clk);
+ pm_runtime_dont_use_autosuspend(dev->dev);
+ pm_runtime_put_sync(dev->dev);
+ pm_runtime_disable(dev->dev);
+
dev->clk = NULL;
return r;
}
@@ -860,16 +896,26 @@ static int davinci_i2c_probe(struct platform_device *pdev)
static int davinci_i2c_remove(struct platform_device *pdev)
{
struct davinci_i2c_dev *dev = platform_get_drvdata(pdev);
+ int ret;
i2c_davinci_cpufreq_deregister(dev);
i2c_del_adapter(&dev->adapter);
- clk_disable_unprepare(dev->clk);
+ ret = pm_runtime_get_sync(&pdev->dev);
+ if (ret < 0) {
+ pm_runtime_put_noidle(&pdev->dev);
+ return ret;
+ }
+
dev->clk = NULL;
davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, 0);
+ pm_runtime_dont_use_autosuspend(dev->dev);
+ pm_runtime_put_sync(dev->dev);
+ pm_runtime_disable(dev->dev);
+
return 0;
}
@@ -880,7 +926,6 @@ static int davinci_i2c_suspend(struct device *dev)
/* put I2C into reset */
davinci_i2c_reset_ctrl(i2c_dev, 0);
- clk_disable_unprepare(i2c_dev->clk);
return 0;
}
@@ -889,7 +934,6 @@ static int davinci_i2c_resume(struct device *dev)
{
struct davinci_i2c_dev *i2c_dev = dev_get_drvdata(dev);
- clk_prepare_enable(i2c_dev->clk);
/* take I2C out of reset */
davinci_i2c_reset_ctrl(i2c_dev, 1);
@@ -899,6 +943,8 @@ static int davinci_i2c_resume(struct device *dev)
static const struct dev_pm_ops davinci_i2c_pm = {
.suspend = davinci_i2c_suspend,
.resume = davinci_i2c_resume,
+ SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+ pm_runtime_force_resume)
};
#define davinci_i2c_pm_ops (&davinci_i2c_pm)
--
2.9.4.dirty
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