[PATCH v4 5/5] mfd: rn5t618: register restart handler

From: Stefan Agner
Date: Tue Jun 28 2016 - 02:28:55 EST


Use the PMIC's repower capability for reboots. Register a restart
handler and use a slightly elevated priority of 192 since the PMIC
has suprior reset capability (causing a system wide reset).

Signed-off-by: Stefan Agner <stefan@xxxxxxxx>
Reviewed-by: Marcel Ziswiler <marcel.ziswiler@xxxxxxxxxxx>
---
drivers/mfd/rn5t618.c | 43 +++++++++++++++++++++++++++++++++++++------
1 file changed, 37 insertions(+), 6 deletions(-)

diff --git a/drivers/mfd/rn5t618.c b/drivers/mfd/rn5t618.c
index 1831740..b3ca6df 100644
--- a/drivers/mfd/rn5t618.c
+++ b/drivers/mfd/rn5t618.c
@@ -12,11 +12,13 @@
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/

+#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/mfd/core.h>
#include <linux/mfd/rn5t618.h>
#include <linux/module.h>
#include <linux/of_device.h>
+#include <linux/reboot.h>
#include <linux/regmap.h>

static const struct mfd_cell rn5t618_cells[] = {
@@ -50,17 +52,38 @@ static const struct regmap_config rn5t618_regmap_config = {
};

static struct rn5t618 *rn5t618_pm_power_off;
+static struct notifier_block rn5t618_restart_handler;

-static void rn5t618_power_off(void)
+static void rn5t618_trigger_poweroff_sequence(bool repower)
{
/* disable automatic repower-on */
regmap_update_bits(rn5t618_pm_power_off->regmap, RN5T618_REPCNT,
- RN5T618_REPCNT_REPWRON, 0);
+ RN5T618_REPCNT_REPWRON,
+ repower ? RN5T618_REPCNT_REPWRON : 0);
/* start power-off sequence */
regmap_update_bits(rn5t618_pm_power_off->regmap, RN5T618_SLPCNT,
RN5T618_SLPCNT_SWPWROFF, RN5T618_SLPCNT_SWPWROFF);
}

+static void rn5t618_power_off(void)
+{
+ rn5t618_trigger_poweroff_sequence(false);
+}
+
+static int rn5t618_restart(struct notifier_block *this,
+ unsigned long mode, void *cmd)
+{
+ rn5t618_trigger_poweroff_sequence(true);
+
+ /*
+ * Repower factor detection on PMIC side is not instant. 1ms
+ * proved to be enouth time until reset takes effect.
+ */
+ mdelay(1);
+
+ return NOTIFY_DONE;
+}
+
static const struct of_device_id rn5t618_of_match[] = {
{ .compatible = "ricoh,rn5t567", .data = (void *)RN5T567 },
{ .compatible = "ricoh,rn5t618", .data = (void *)RN5T618 },
@@ -102,13 +125,21 @@ static int rn5t618_i2c_probe(struct i2c_client *i2c,
return ret;
}

+ rn5t618_pm_power_off = priv;
if (of_device_is_system_power_controller(i2c->dev.of_node)) {
- if (!pm_power_off) {
- rn5t618_pm_power_off = priv;
+ if (!pm_power_off)
pm_power_off = rn5t618_power_off;
- } else {
+ else
dev_warn(&i2c->dev, "Poweroff callback already assigned\n");
- }
+ }
+
+ rn5t618_restart_handler.notifier_call = rn5t618_restart;
+ rn5t618_restart_handler.priority = 192;
+
+ ret = register_restart_handler(&rn5t618_restart_handler);
+ if (ret) {
+ dev_err(&i2c->dev, "cannot register restart handler, %d\n", ret);
+ return ret;
}

return 0;
--
2.8.3