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Message-ID: <1580752328-26009-1-git-send-email-alain.volmat@st.com>
Date: Mon, 3 Feb 2020 18:52:08 +0100
From: Alain Volmat <alain.volmat@...com>
To: <wsa@...-dreams.de>, <pierre-yves.mordret@...com>
CC: <alain.volmat@...com>, <alexandre.torgue@...com>,
<linux-i2c@...r.kernel.org>,
<linux-stm32@...md-mailman.stormreply.com>,
<linux-arm-kernel@...ts.infradead.org>,
<linux-kernel@...r.kernel.org>, <fabrice.gasnier@...com>
Subject: [PATCHv2] i2c: i2c-stm32f7: allow controller to be wakeup-source
Allow the i2c-stm32f7 controller to become a wakeup-source
of the system. In such case, when a slave is registered to the
I2C controller, receiving a I2C message targeting that registered
slave address wakes up the suspended system.
In order to be able to wake-up, the I2C controller DT node
must have the property wakeup-source defined and a slave
must be registered.
Signed-off-by: Alain Volmat <alain.volmat@...com>
---
v2: - enclose _suspend and _resume functions (and related) with
#ifdef CONFIG_PM_SLEEP
- remove the __maybe_unused for functions enclosed with CONFIG_PM_SLEEP
- move stm32f7_i2c_enable_wakeup function upper in the file to avoid
having a prototype.
drivers/i2c/busses/i2c-stm32f7.c | 107 +++++++++++++++++++++++++------
1 file changed, 86 insertions(+), 21 deletions(-)
diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
index 5c3e8ac6ad92..378956ac6d1d 100644
--- a/drivers/i2c/busses/i2c-stm32f7.c
+++ b/drivers/i2c/busses/i2c-stm32f7.c
@@ -29,6 +29,7 @@
#include <linux/platform_device.h>
#include <linux/pinctrl/consumer.h>
#include <linux/pm_runtime.h>
+#include <linux/pm_wakeirq.h>
#include <linux/regmap.h>
#include <linux/reset.h>
#include <linux/slab.h>
@@ -49,6 +50,7 @@
/* STM32F7 I2C control 1 */
#define STM32F7_I2C_CR1_PECEN BIT(23)
+#define STM32F7_I2C_CR1_WUPEN BIT(18)
#define STM32F7_I2C_CR1_SBC BIT(16)
#define STM32F7_I2C_CR1_RXDMAEN BIT(15)
#define STM32F7_I2C_CR1_TXDMAEN BIT(14)
@@ -301,6 +303,7 @@ struct stm32f7_i2c_msg {
* @dma: dma data
* @use_dma: boolean to know if dma is used in the current transfer
* @regmap: holds SYSCFG phandle for Fast Mode Plus bits
+ * @wakeup_src: boolean to know if the device is a wakeup source
*/
struct stm32f7_i2c_dev {
struct i2c_adapter adap;
@@ -323,6 +326,7 @@ struct stm32f7_i2c_dev {
struct stm32_i2c_dma *dma;
bool use_dma;
struct regmap *regmap;
+ bool wakeup_src;
};
/*
@@ -1691,6 +1695,24 @@ static int stm32f7_i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
return ret;
}
+static void stm32f7_i2c_enable_wakeup(struct stm32f7_i2c_dev *i2c_dev,
+ bool enable)
+{
+ void __iomem *base = i2c_dev->base;
+ u32 mask = STM32F7_I2C_CR1_WUPEN;
+
+ if (!i2c_dev->wakeup_src)
+ return;
+
+ if (enable) {
+ device_set_wakeup_enable(i2c_dev->dev, true);
+ stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask);
+ } else {
+ device_set_wakeup_enable(i2c_dev->dev, false);
+ stm32f7_i2c_clr_bits(base + STM32F7_I2C_CR1, mask);
+ }
+}
+
static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
{
struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(slave->adapter);
@@ -1717,6 +1739,9 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
if (ret < 0)
return ret;
+ if (!stm32f7_i2c_is_slave_registered(i2c_dev))
+ stm32f7_i2c_enable_wakeup(i2c_dev, true);
+
if (id == 0) {
/* Configure Own Address 1 */
oar1 = readl_relaxed(i2c_dev->base + STM32F7_I2C_OAR1);
@@ -1758,6 +1783,9 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
ret = 0;
pm_free:
+ if (!stm32f7_i2c_is_slave_registered(i2c_dev))
+ stm32f7_i2c_enable_wakeup(i2c_dev, false);
+
pm_runtime_mark_last_busy(dev);
pm_runtime_put_autosuspend(dev);
@@ -1791,8 +1819,10 @@ static int stm32f7_i2c_unreg_slave(struct i2c_client *slave)
i2c_dev->slave[id] = NULL;
- if (!(stm32f7_i2c_is_slave_registered(i2c_dev)))
+ if (!stm32f7_i2c_is_slave_registered(i2c_dev)) {
stm32f7_i2c_disable_irq(i2c_dev, STM32F7_I2C_ALL_IRQ_MASK);
+ stm32f7_i2c_enable_wakeup(i2c_dev, false);
+ }
pm_runtime_mark_last_busy(i2c_dev->dev);
pm_runtime_put_autosuspend(i2c_dev->dev);
@@ -1879,6 +1909,9 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)
return irq_error ? : -ENOENT;
}
+ i2c_dev->wakeup_src = of_property_read_bool(pdev->dev.of_node,
+ "wakeup-source");
+
i2c_dev->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(i2c_dev->clk)) {
dev_err(&pdev->dev, "Error: Missing controller clock\n");
@@ -1985,6 +2018,16 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)
goto clk_free;
}
+ if (i2c_dev->wakeup_src) {
+ device_set_wakeup_capable(i2c_dev->dev, true);
+
+ ret = dev_pm_set_wake_irq(i2c_dev->dev, irq_event);
+ if (ret) {
+ dev_err(i2c_dev->dev, "Failed to set wake up irq\n");
+ goto clr_wakeup_capable;
+ }
+ }
+
platform_set_drvdata(pdev, i2c_dev);
pm_runtime_set_autosuspend_delay(i2c_dev->dev,
@@ -2014,6 +2057,13 @@ static int stm32f7_i2c_probe(struct platform_device *pdev)
pm_runtime_set_suspended(i2c_dev->dev);
pm_runtime_dont_use_autosuspend(i2c_dev->dev);
+ if (i2c_dev->wakeup_src)
+ dev_pm_clear_wake_irq(i2c_dev->dev);
+
+clr_wakeup_capable:
+ if (i2c_dev->wakeup_src)
+ device_set_wakeup_capable(i2c_dev->dev, false);
+
if (i2c_dev->dma) {
stm32_i2c_dma_free(i2c_dev->dma);
i2c_dev->dma = NULL;
@@ -2032,6 +2082,15 @@ static int stm32f7_i2c_remove(struct platform_device *pdev)
i2c_del_adapter(&i2c_dev->adap);
pm_runtime_get_sync(i2c_dev->dev);
+ if (i2c_dev->wakeup_src) {
+ dev_pm_clear_wake_irq(i2c_dev->dev);
+ /*
+ * enforce that wakeup is disabled and that the device
+ * is marked as non wakeup capable
+ */
+ device_init_wakeup(i2c_dev->dev, false);
+ }
+
pm_runtime_put_noidle(i2c_dev->dev);
pm_runtime_disable(i2c_dev->dev);
pm_runtime_set_suspended(i2c_dev->dev);
@@ -2073,8 +2132,8 @@ static int __maybe_unused stm32f7_i2c_runtime_resume(struct device *dev)
return 0;
}
-static int __maybe_unused
-stm32f7_i2c_regs_backup(struct stm32f7_i2c_dev *i2c_dev)
+#ifdef CONFIG_PM_SLEEP
+static int stm32f7_i2c_regs_backup(struct stm32f7_i2c_dev *i2c_dev)
{
int ret;
struct stm32f7_i2c_regs *backup_regs = &i2c_dev->backup_regs;
@@ -2095,8 +2154,7 @@ stm32f7_i2c_regs_backup(struct stm32f7_i2c_dev *i2c_dev)
return ret;
}
-static int __maybe_unused
-stm32f7_i2c_regs_restore(struct stm32f7_i2c_dev *i2c_dev)
+static int stm32f7_i2c_regs_restore(struct stm32f7_i2c_dev *i2c_dev)
{
u32 cr1;
int ret;
@@ -2127,41 +2185,48 @@ stm32f7_i2c_regs_restore(struct stm32f7_i2c_dev *i2c_dev)
return ret;
}
-static int __maybe_unused stm32f7_i2c_suspend(struct device *dev)
+static int stm32f7_i2c_suspend(struct device *dev)
{
struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev);
int ret;
i2c_mark_adapter_suspended(&i2c_dev->adap);
- ret = stm32f7_i2c_regs_backup(i2c_dev);
- if (ret < 0) {
- i2c_mark_adapter_resumed(&i2c_dev->adap);
- return ret;
- }
- pinctrl_pm_select_sleep_state(dev);
- pm_runtime_force_suspend(dev);
+ if (!device_may_wakeup(dev) && !dev->power.wakeup_path) {
+ ret = stm32f7_i2c_regs_backup(i2c_dev);
+ if (ret < 0) {
+ i2c_mark_adapter_resumed(&i2c_dev->adap);
+ return ret;
+ }
+
+ pinctrl_pm_select_sleep_state(dev);
+ pm_runtime_force_suspend(dev);
+ }
return 0;
}
-static int __maybe_unused stm32f7_i2c_resume(struct device *dev)
+static int stm32f7_i2c_resume(struct device *dev)
{
struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev);
int ret;
- ret = pm_runtime_force_resume(dev);
- if (ret < 0)
- return ret;
- pinctrl_pm_select_default_state(dev);
+ if (!device_may_wakeup(dev) && !dev->power.wakeup_path) {
+ ret = pm_runtime_force_resume(dev);
+ if (ret < 0)
+ return ret;
+ pinctrl_pm_select_default_state(dev);
+
+ ret = stm32f7_i2c_regs_restore(i2c_dev);
+ if (ret < 0)
+ return ret;
+ }
- ret = stm32f7_i2c_regs_restore(i2c_dev);
- if (ret < 0)
- return ret;
i2c_mark_adapter_resumed(&i2c_dev->adap);
return 0;
}
+#endif
static const struct dev_pm_ops stm32f7_i2c_pm_ops = {
SET_RUNTIME_PM_OPS(stm32f7_i2c_runtime_suspend,
--
2.17.1
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