[PATCH v4 2/2] mfd: rk808: Add restart functionality

From: Daniel Schultz
Date: Fri Mar 16 2018 - 12:49:03 EST


When using Rockchip SoCs with rk805/808/818 PMICs, restarts are realized by
setting the reset registers in the "Clock and Reset Unit".

Now, the driver can trigger a restart in the PMIC. Like the
shutdown function, the restart is bound to an independent
"rockchip,system-reset-controller" devicetree property can easily
enabled by adding this.

Signed-off-by: Daniel Schultz <d.schultz@xxxxxxxxx>
---
Changes:
v2: Re-submit with recipients from Rockchip.
v3: - Added devicetree property to enable the PMIC reset seperate from
"rockchip,system-power-controller".
- Dropped the first patch of this serie.
v4: Splitted refactoring and the new reset feature.

drivers/mfd/rk808.c | 58 ++++++++++++++++++++++++++++++++++++++++++-----
include/linux/mfd/rk808.h | 1 +
2 files changed, 53 insertions(+), 6 deletions(-)

diff --git a/drivers/mfd/rk808.c b/drivers/mfd/rk808.c
index ae014ee..7dccf8f 100644
--- a/drivers/mfd/rk808.c
+++ b/drivers/mfd/rk808.c
@@ -27,6 +27,7 @@
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/regmap.h>
+#include <linux/reboot.h>

struct rk808_reg_data {
int addr;
@@ -393,16 +394,49 @@ static void rk805_device_shutdown(void)
{
rk808_update_bits(RK805_DEV_CTRL_REG, DEV_OFF);
}
+static int rk805_restart_notify(struct notifier_block *this,
+ unsigned long mode, void *cmd)
+{
+ rk808_update_bits(RK805_DEV_CTRL_REG, DEV_OFF_RST);
+ return NOTIFY_DONE;
+}

static void rk808_device_shutdown(void)
{
rk808_update_bits(RK808_DEVCTRL_REG, DEV_OFF_RST);
}
+static int rk808_restart_notify(struct notifier_block *this,
+ unsigned long mode, void *cmd)
+{
+ rk808_update_bits(RK808_DEVCTRL_REG, DEV_OFF);
+ return NOTIFY_DONE;
+}

static void rk818_device_shutdown(void)
{
rk808_update_bits(RK818_DEVCTRL_REG, DEV_OFF);
}
+static int rk818_restart_notify(struct notifier_block *this,
+ unsigned long mode, void *cmd)
+{
+ rk808_update_bits(RK818_DEVCTRL_REG, DEV_OFF_RST);
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block rk805_restart_handler = {
+ .notifier_call = rk805_restart_notify,
+ .priority = 196,
+};
+
+static struct notifier_block rk808_restart_handler = {
+ .notifier_call = rk808_restart_notify,
+ .priority = 196,
+};
+
+static struct notifier_block rk818_restart_handler = {
+ .notifier_call = rk818_restart_notify,
+ .priority = 196,
+};

static const struct of_device_id rk808_of_match[] = {
{ .compatible = "rockchip,rk805" },
@@ -422,7 +456,7 @@ static int rk808_probe(struct i2c_client *client,
void (*pm_pwroff_fn)(void);
int nr_pre_init_regs;
int nr_cells;
- int pm_off = 0, msb, lsb;
+ int pm_off = 0, pm_rst_off = 0, msb, lsb;
int ret;
int i;

@@ -457,6 +491,7 @@ static int rk808_probe(struct i2c_client *client,
cells = rk805s;
nr_cells = ARRAY_SIZE(rk805s);
pm_pwroff_fn = rk805_device_shutdown;
+ rk808->nb = &rk805_restart_handler;
break;
case RK808_ID:
rk808->regmap_cfg = &rk808_regmap_config;
@@ -466,6 +501,7 @@ static int rk808_probe(struct i2c_client *client,
cells = rk808s;
nr_cells = ARRAY_SIZE(rk808s);
pm_pwroff_fn = rk808_device_shutdown;
+ rk808->nb = &rk808_restart_handler;
break;
case RK818_ID:
rk808->regmap_cfg = &rk818_regmap_config;
@@ -475,6 +511,7 @@ static int rk808_probe(struct i2c_client *client,
cells = rk818s;
nr_cells = ARRAY_SIZE(rk818s);
pm_pwroff_fn = rk818_device_shutdown;
+ rk808->nb = &rk818_restart_handler;
break;
default:
dev_err(&client->dev, "Unsupported RK8XX ID %lu\n",
@@ -525,13 +562,20 @@ static int rk808_probe(struct i2c_client *client,
goto err_irq;
}

- pm_off = of_property_read_bool(np,
- "rockchip,system-power-controller");
- if (pm_off && !pm_power_off) {
- rk808_i2c_client = client;
+ rk808_i2c_client = client;
+
+ pm_off = of_property_read_bool(np, "rockchip,system-power-controller");
+ if (pm_off && !pm_power_off)
pm_power_off = pm_pwroff_fn;
- }

+ pm_rst_off = of_property_read_bool(np,
+ "rockchip,system-reset-controller");
+ if (pm_rst_off && rk808->nb) {
+ ret = register_restart_handler(rk808->nb);
+ if (ret)
+ dev_err(&client->dev,
+ "cannot register restart handler, %d\n", ret);
+ }
return 0;

err_irq:
@@ -545,6 +589,8 @@ static int rk808_remove(struct i2c_client *client)

regmap_del_irq_chip(client->irq, rk808->irq_data);
pm_power_off = NULL;
+ if (rk808->nb)
+ unregister_restart_handler(rk808->nb);

return 0;
}
diff --git a/include/linux/mfd/rk808.h b/include/linux/mfd/rk808.h
index 338e0f6..9c26ca2 100644
--- a/include/linux/mfd/rk808.h
+++ b/include/linux/mfd/rk808.h
@@ -453,5 +453,6 @@ struct rk808 {
long variant;
const struct regmap_config *regmap_cfg;
const struct regmap_irq_chip *regmap_irq_chip;
+ struct notifier_block *nb;
};
#endif /* __LINUX_REGULATOR_RK808_H */
--
2.7.4