mfd: rohm-bd71828: Add power off functionality

Since the chip can power off the system, add the corresponding
functionality.
Based on https://github.com/kobolabs/Kobo-Reader/raw/master/hw/imx6sll-clara2e/kernel.tar.bz2

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Acked-by: Matti Vaittinen <mazziesaccount@gmail.com>
Link: https://lore.kernel.org/r/20240402111700.494004-3-andreas@kemnade.info
Signed-off-by: Lee Jones <lee@kernel.org>

diff --git a/drivers/mfd/rohm-bd71828.c b/drivers/mfd/rohm-bd71828.c
index 2f3826c7eef49b9970ba91e200b39cc7641b540c..5b4290f116fc78ca3ea13d64035cd3782fdbbb82 100644 (file)
--- a/drivers/mfd/rohm-bd71828.c
+++ b/drivers/mfd/rohm-bd71828.c
@@ -464,6 +464,27 @@ static int set_clk_mode(struct device *dev, struct regmap *regmap,
                                  OUT32K_MODE_CMOS);
 }
 
+static struct i2c_client *bd71828_dev;
+static void bd71828_power_off(void)
+{
+       while (true) {
+               s32 val;
+
+               /* We are not allowed to sleep, so do not use regmap involving mutexes here. */
+               val = i2c_smbus_read_byte_data(bd71828_dev, BD71828_REG_PS_CTRL_1);
+               if (val >= 0)
+                       i2c_smbus_write_byte_data(bd71828_dev,
+                                                 BD71828_REG_PS_CTRL_1,
+                                                 BD71828_MASK_STATE_HBNT | (u8)val);
+               mdelay(500);
+       }
+}
+
+static void bd71828_remove_poweroff(void *data)
+{
+       pm_power_off = NULL;
+}
+
 static int bd71828_i2c_probe(struct i2c_client *i2c)
 {
        struct regmap_irq_chip_data *irq_data;
@@ -542,7 +563,20 @@ static int bd71828_i2c_probe(struct i2c_client *i2c)
        ret = devm_mfd_add_devices(&i2c->dev, PLATFORM_DEVID_AUTO, mfd, cells,
                                   NULL, 0, regmap_irq_get_domain(irq_data));
        if (ret)
-               dev_err_probe(&i2c->dev, ret, "Failed to create subdevices\n");
+               return  dev_err_probe(&i2c->dev, ret, "Failed to create subdevices\n");
+
+       if (of_device_is_system_power_controller(i2c->dev.of_node) &&
+           chip_type == ROHM_CHIP_TYPE_BD71828) {
+               if (!pm_power_off) {
+                       bd71828_dev = i2c;
+                       pm_power_off = bd71828_power_off;
+                       ret = devm_add_action_or_reset(&i2c->dev,
+                                                      bd71828_remove_poweroff,
+                                                      NULL);
+               } else {
+                       dev_warn(&i2c->dev, "Poweroff callback already assigned\n");
+               }
+       }
 
        return ret;
 }

diff --git a/include/linux/mfd/rohm-bd71828.h b/include/linux/mfd/rohm-bd71828.h
index 3b5f3a7db4bd66cb4fa445a587ab69abec3a0c24..9776fde1262d1b8ce7450eaeac4ffa21d0eec2df 100644 (file)
--- a/include/linux/mfd/rohm-bd71828.h
+++ b/include/linux/mfd/rohm-bd71828.h
@@ -4,6 +4,7 @@
 #ifndef __LINUX_MFD_BD71828_H__
 #define __LINUX_MFD_BD71828_H__
 
+#include <linux/bits.h>
 #include <linux/mfd/rohm-generic.h>
 #include <linux/mfd/rohm-shared.h>
 
@@ -41,6 +42,8 @@ enum {
 #define BD71828_REG_PS_CTRL_2          0x05
 #define BD71828_REG_PS_CTRL_3          0x06
 
+#define BD71828_MASK_STATE_HBNT                BIT(1)
+
 //#define BD71828_REG_SWRESET          0x06
 #define BD71828_MASK_RUN_LVL_CTRL      0x30