Re: [PATCH v3 2/2] mfd: rohm-bd71828: Add power off functionality

From: Matti Vaittinen
Date: Thu Apr 11 2024 - 08:15:07 EST


On 4/11/24 14:50, Lee Jones wrote:
On Tue, 02 Apr 2024, Andreas Kemnade wrote:

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@xxxxxxxxxxxx>
Acked-by: Matti Vaittinen <mazziesaccount@xxxxxxxxx>
---
drivers/mfd/rohm-bd71828.c | 36 +++++++++++++++++++++++++++++++-
include/linux/mfd/rohm-bd71828.h | 3 +++
2 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/drivers/mfd/rohm-bd71828.c b/drivers/mfd/rohm-bd71828.c
index 594718f7e8e1..4a1fa8a0d76a 100644
--- 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 3b5f3a7db4bd..9776fde1262d 100644
--- 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

How did this get in here?

Don't blame me, blame git... Errm... :)
[mvaittin@fedora linux]$ git blame include/linux/mfd/rohm-bd71828.h |grep \/\/
1c743ad523bb2 (Matti Vaittinen 2020-01-20 15:43:28 +0200 44) //#define BD71828_REG_SWRESET 0x06
1c743ad523bb2 (Matti Vaittinen 2020-01-20 15:43:28 +0200 136) //#define BD71828_REG_LDO6_VOLT 0x4

I can send a clean-up patch unless you want to do it while applying other stuff...

Yours,
Matti

--
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland

~~ When things go utterly wrong vim users can always type :help! ~~