diff options
author | Hans de Goede <hdegoede@redhat.com> | 2023-03-04 01:19:28 +0300 |
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committer | Hans de Goede <hdegoede@redhat.com> | 2023-03-16 16:42:30 +0300 |
commit | 94227b9c88f3df8ac3025611719cebd125b5981a (patch) | |
tree | 360d67c0b08928b290badf25cb12a03273dd5cac /drivers/platform/x86/intel/bytcrc_pwrsrc.c | |
parent | de4fb5f5165582caf21b9074b918acccf99582a1 (diff) | |
download | linux-94227b9c88f3df8ac3025611719cebd125b5981a.tar.xz |
platform/x86: Add intel_bytcrc_pwrsrc driver
Add a new driver for the power-, wake- and reset-source functionality
of the Bay Trail (BYT) version of the Crystal Cove PMIC.
The main functionality here is detecting which power-sources (USB /
DC in / battery) are active. This is normally exposed to userspace as
a power_supply class charger device with an online sysfs attribute.
But if a charger is online or not is already exposed on BYT-CRC devices
through either an ACPI AC power_supply device, or through a native driver
for the battery charger chip (e.g. a BQ24292i).
So instead of adding duplicate info under the power_supply class this
driver exports the info through debugfs and likewise adds debugfs files
for the reset- and wake-source info / registers.
Despite this driver only exporting debugfs bits it is still useful to
have this driver because it clears the wake- and reset-source registers
after reading them. Not clearing these can have undesirable side-effects.
Specifically if the WAKESRC register contains 0x01 (wake by powerbutton)
on reboot then the firmware on some tablets turns the reboot into
a poweroff. I guess this may be necessary to make long power-presses turn
into a poweroff somehow?
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230303221928.285477-1-hdegoede@redhat.com
Diffstat (limited to 'drivers/platform/x86/intel/bytcrc_pwrsrc.c')
-rw-r--r-- | drivers/platform/x86/intel/bytcrc_pwrsrc.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/drivers/platform/x86/intel/bytcrc_pwrsrc.c b/drivers/platform/x86/intel/bytcrc_pwrsrc.c new file mode 100644 index 000000000000..8a022b90d12d --- /dev/null +++ b/drivers/platform/x86/intel/bytcrc_pwrsrc.c @@ -0,0 +1,181 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Power-source driver for Bay Trail Crystal Cove PMIC + * + * Copyright (c) 2023 Hans de Goede <hdegoede@redhat.com> + * + * Based on intel_crystalcove_pwrsrc.c from Android kernel sources, which is: + * Copyright (C) 2013 Intel Corporation + */ + +#include <linux/debugfs.h> +#include <linux/mfd/intel_soc_pmic.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> + +#define CRYSTALCOVE_SPWRSRC_REG 0x1E +#define CRYSTALCOVE_RESETSRC0_REG 0x20 +#define CRYSTALCOVE_RESETSRC1_REG 0x21 +#define CRYSTALCOVE_WAKESRC_REG 0x22 + +struct crc_pwrsrc_data { + struct regmap *regmap; + struct dentry *debug_dentry; + unsigned int resetsrc0; + unsigned int resetsrc1; + unsigned int wakesrc; +}; + +static const char * const pwrsrc_pwrsrc_info[] = { + /* bit 0 */ "USB", + /* bit 1 */ "DC in", + /* bit 2 */ "Battery", + NULL, +}; + +static const char * const pwrsrc_resetsrc0_info[] = { + /* bit 0 */ "SOC reporting a thermal event", + /* bit 1 */ "critical PMIC temperature", + /* bit 2 */ "critical system temperature", + /* bit 3 */ "critical battery temperature", + /* bit 4 */ "VSYS under voltage", + /* bit 5 */ "VSYS over voltage", + /* bit 6 */ "battery removal", + NULL, +}; + +static const char * const pwrsrc_resetsrc1_info[] = { + /* bit 0 */ "VCRIT threshold", + /* bit 1 */ "BATID reporting battery removal", + /* bit 2 */ "user pressing the power button", + NULL, +}; + +static const char * const pwrsrc_wakesrc_info[] = { + /* bit 0 */ "user pressing the power button", + /* bit 1 */ "a battery insertion", + /* bit 2 */ "a USB charger insertion", + /* bit 3 */ "an adapter insertion", + NULL, +}; + +static void crc_pwrsrc_log(struct seq_file *seq, const char *prefix, + const char * const *info, unsigned int reg_val) +{ + int i; + + for (i = 0; info[i]; i++) { + if (reg_val & BIT(i)) + seq_printf(seq, "%s by %s\n", prefix, info[i]); + } +} + +static int pwrsrc_show(struct seq_file *seq, void *unused) +{ + struct crc_pwrsrc_data *data = seq->private; + unsigned int reg_val; + int ret; + + ret = regmap_read(data->regmap, CRYSTALCOVE_SPWRSRC_REG, ®_val); + if (ret) + return ret; + + crc_pwrsrc_log(seq, "System powered", pwrsrc_pwrsrc_info, reg_val); + return 0; +} + +static int resetsrc_show(struct seq_file *seq, void *unused) +{ + struct crc_pwrsrc_data *data = seq->private; + + crc_pwrsrc_log(seq, "Last shutdown caused", pwrsrc_resetsrc0_info, data->resetsrc0); + crc_pwrsrc_log(seq, "Last shutdown caused", pwrsrc_resetsrc1_info, data->resetsrc1); + return 0; +} + +static int wakesrc_show(struct seq_file *seq, void *unused) +{ + struct crc_pwrsrc_data *data = seq->private; + + crc_pwrsrc_log(seq, "Last wake caused", pwrsrc_wakesrc_info, data->wakesrc); + return 0; +} + +DEFINE_SHOW_ATTRIBUTE(pwrsrc); +DEFINE_SHOW_ATTRIBUTE(resetsrc); +DEFINE_SHOW_ATTRIBUTE(wakesrc); + +static int crc_pwrsrc_read_and_clear(struct crc_pwrsrc_data *data, + unsigned int reg, unsigned int *val) +{ + int ret; + + ret = regmap_read(data->regmap, reg, val); + if (ret) + return ret; + + return regmap_write(data->regmap, reg, *val); +} + +static int crc_pwrsrc_probe(struct platform_device *pdev) +{ + struct intel_soc_pmic *pmic = dev_get_drvdata(pdev->dev.parent); + struct crc_pwrsrc_data *data; + int ret; + + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->regmap = pmic->regmap; + + /* + * Read + clear resetsrc0/1 and wakesrc now, so that they get + * cleared even if the debugfs interface is never used. + * + * Properly clearing the wakesrc is important, leaving bit 0 of it + * set turns reboot into poweroff on some tablets. + */ + ret = crc_pwrsrc_read_and_clear(data, CRYSTALCOVE_RESETSRC0_REG, &data->resetsrc0); + if (ret) + return ret; + + ret = crc_pwrsrc_read_and_clear(data, CRYSTALCOVE_RESETSRC1_REG, &data->resetsrc1); + if (ret) + return ret; + + ret = crc_pwrsrc_read_and_clear(data, CRYSTALCOVE_WAKESRC_REG, &data->wakesrc); + if (ret) + return ret; + + data->debug_dentry = debugfs_create_dir(KBUILD_MODNAME, NULL); + debugfs_create_file("pwrsrc", 0444, data->debug_dentry, data, &pwrsrc_fops); + debugfs_create_file("resetsrc", 0444, data->debug_dentry, data, &resetsrc_fops); + debugfs_create_file("wakesrc", 0444, data->debug_dentry, data, &wakesrc_fops); + + platform_set_drvdata(pdev, data); + return 0; +} + +static int crc_pwrsrc_remove(struct platform_device *pdev) +{ + struct crc_pwrsrc_data *data = platform_get_drvdata(pdev); + + debugfs_remove_recursive(data->debug_dentry); + return 0; +} + +static struct platform_driver crc_pwrsrc_driver = { + .probe = crc_pwrsrc_probe, + .remove = crc_pwrsrc_remove, + .driver = { + .name = "crystal_cove_pwrsrc", + }, +}; +module_platform_driver(crc_pwrsrc_driver); + +MODULE_ALIAS("platform:crystal_cove_pwrsrc"); +MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>"); +MODULE_DESCRIPTION("Power-source driver for Bay Trail Crystal Cove PMIC"); +MODULE_LICENSE("GPL"); |