linux/drivers/mfd/acer-ec-a500.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Acer Iconia Tab A500 Embedded Controller Driver
*
* Copyright 2020 GRATE-driver project
*/
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/mfd/core.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/reboot.h>
#include <linux/regmap.h>
#define A500_EC_I2C_ERR_TIMEOUT 500
#define A500_EC_POWER_CMD_TIMEOUT 1000
/*
* Controller's firmware expects specific command opcodes to be used for the
* corresponding registers. Unsupported commands are skipped by the firmware.
*/
#define CMD_SHUTDOWN 0x0
#define CMD_WARM_REBOOT 0x0
#define CMD_COLD_REBOOT 0x1
enum {
REG_CURRENT_NOW = 0x03,
REG_SHUTDOWN = 0x52,
REG_WARM_REBOOT = 0x54,
REG_COLD_REBOOT = 0x55,
};
static struct i2c_client *a500_ec_client_pm_off;
static int a500_ec_read(void *context, const void *reg_buf, size_t reg_size,
void *val_buf, size_t val_sizel)
{
struct i2c_client *client = context;
unsigned int reg, retries = 5;
u16 *ret_val = val_buf;
s32 ret = 0;
reg = *(u8 *)reg_buf;
while (retries-- > 0) {
ret = i2c_smbus_read_word_data(client, reg);
if (ret >= 0)
break;
msleep(A500_EC_I2C_ERR_TIMEOUT);
}
if (ret < 0) {
dev_err(&client->dev, "read 0x%x failed: %d\n", reg, ret);
return ret;
}
*ret_val = ret;
if (reg == REG_CURRENT_NOW)
fsleep(10000);
return 0;
}
static int a500_ec_write(void *context, const void *data, size_t count)
{
struct i2c_client *client = context;
unsigned int reg, val, retries = 5;
s32 ret = 0;
reg = *(u8 *)(data + 0);
val = *(u16 *)(data + 1);
while (retries-- > 0) {
ret = i2c_smbus_write_word_data(client, reg, val);
if (ret >= 0)
break;
msleep(A500_EC_I2C_ERR_TIMEOUT);
}
if (ret < 0) {
dev_err(&client->dev, "write 0x%x failed: %d\n", reg, ret);
return ret;
}
return 0;
}
static const struct regmap_config a500_ec_regmap_config = {
.name = "KB930",
.reg_bits = 8,
.val_bits = 16,
.max_register = 0xff,
};
static const struct regmap_bus a500_ec_regmap_bus = {
.reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
.val_format_endian_default = REGMAP_ENDIAN_LITTLE,
.write = a500_ec_write,
.read = a500_ec_read,
.max_raw_read = 2,
};
static void a500_ec_poweroff(void)
{
i2c_smbus_write_word_data(a500_ec_client_pm_off,
REG_SHUTDOWN, CMD_SHUTDOWN);
mdelay(A500_EC_POWER_CMD_TIMEOUT);
}
static int a500_ec_restart_notify(struct notifier_block *this,
unsigned long reboot_mode, void *data)
{
if (reboot_mode == REBOOT_WARM)
i2c_smbus_write_word_data(a500_ec_client_pm_off,
REG_WARM_REBOOT, CMD_WARM_REBOOT);
else
i2c_smbus_write_word_data(a500_ec_client_pm_off,
REG_COLD_REBOOT, CMD_COLD_REBOOT);
mdelay(A500_EC_POWER_CMD_TIMEOUT);
return NOTIFY_DONE;
}
static struct notifier_block a500_ec_restart_handler = {
.notifier_call = a500_ec_restart_notify,
.priority = 200,
};
static const struct mfd_cell a500_ec_cells[] = {
{ .name = "acer-a500-iconia-battery", },
{ .name = "acer-a500-iconia-leds", },
};
static int a500_ec_probe(struct i2c_client *client)
{
struct regmap *regmap;
int err;
regmap = devm_regmap_init(&client->dev, &a500_ec_regmap_bus,
client, &a500_ec_regmap_config);
if (IS_ERR(regmap))
return PTR_ERR(regmap);
err = devm_mfd_add_devices(&client->dev, PLATFORM_DEVID_AUTO,
a500_ec_cells, ARRAY_SIZE(a500_ec_cells),
NULL, 0, NULL);
if (err) {
dev_err(&client->dev, "failed to add sub-devices: %d\n", err);
return err;
}
if (of_device_is_system_power_controller(client->dev.of_node)) {
a500_ec_client_pm_off = client;
err = register_restart_handler(&a500_ec_restart_handler);
if (err)
return err;
if (!pm_power_off)
pm_power_off = a500_ec_poweroff;
}
return 0;
}
i2c: Make remove callback return void The value returned by an i2c driver's remove function is mostly ignored. (Only an error message is printed if the value is non-zero that the error is ignored.) So change the prototype of the remove function to return no value. This way driver authors are not tempted to assume that passing an error to the upper layer is a good idea. All drivers are adapted accordingly. There is no intended change of behaviour, all callbacks were prepared to return 0 before. Reviewed-by: Peter Senna Tschudin <peter.senna@gmail.com> Reviewed-by: Jeremy Kerr <jk@codeconstruct.com.au> Reviewed-by: Benjamin Mugnier <benjamin.mugnier@foss.st.com> Reviewed-by: Javier Martinez Canillas <javierm@redhat.com> Reviewed-by: Crt Mori <cmo@melexis.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Marek Behún <kabel@kernel.org> # for leds-turris-omnia Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Machata <petrm@nvidia.com> # for mlxsw Reviewed-by: Maximilian Luz <luzmaximilian@gmail.com> # for surface3_power Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> # for bmc150-accel-i2c + kxcjk-1013 Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> # for media/* + staging/media/* Acked-by: Miguel Ojeda <ojeda@kernel.org> # for auxdisplay/ht16k33 + auxdisplay/lcd2s Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com> # for versaclock5 Reviewed-by: Ajay Gupta <ajayg@nvidia.com> # for ucsi_ccg Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # for iio Acked-by: Peter Rosin <peda@axentia.se> # for i2c-mux-*, max9860 Acked-by: Adrien Grassein <adrien.grassein@gmail.com> # for lontium-lt8912b Reviewed-by: Jean Delvare <jdelvare@suse.de> # for hwmon, i2c-core and i2c/muxes Acked-by: Corey Minyard <cminyard@mvista.com> # for IPMI Reviewed-by: Vladimir Oltean <olteanv@gmail.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com> # for drivers/power Acked-by: Krzysztof Hałasa <khalasa@piap.pl> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Wolfram Sang <wsa@kernel.org>
2022-08-15 08:02:30 +00:00
static void a500_ec_remove(struct i2c_client *client)
{
if (of_device_is_system_power_controller(client->dev.of_node)) {
if (pm_power_off == a500_ec_poweroff)
pm_power_off = NULL;
unregister_restart_handler(&a500_ec_restart_handler);
}
}
static const struct of_device_id a500_ec_match[] = {
{ .compatible = "acer,a500-iconia-ec" },
{ }
};
MODULE_DEVICE_TABLE(of, a500_ec_match);
static struct i2c_driver a500_ec_driver = {
.driver = {
.name = "acer-a500-embedded-controller",
.of_match_table = a500_ec_match,
},
.probe_new = a500_ec_probe,
.remove = a500_ec_remove,
};
module_i2c_driver(a500_ec_driver);
MODULE_DESCRIPTION("Acer Iconia Tab A500 Embedded Controller driver");
MODULE_AUTHOR("Dmitry Osipenko <digetx@gmail.com>");
MODULE_LICENSE("GPL");