diff mbox series

[v8,2/3] mfd: Add driver for Embedded Controller found on Acer Iconia Tab A500

Message ID 20201228160547.30562-3-digetx@gmail.com
State Accepted
Commit 92eba6802c2b1ffb30f1454e9d99ef980b94bbbf
Headers show
Series Introduce Embedded Controller driver for Acer A500 | expand

Commit Message

Dmitry Osipenko Dec. 28, 2020, 4:05 p.m. UTC
Acer Iconia Tab A500 is an Android tablet device, it has ENE KB930
Embedded Controller which provides battery-gauge, LED, GPIO and some
other functions. The EC uses firmware that is specifically customized
for Acer A500. This patch adds MFD driver for the Embedded Controller
which allows to power-off / reboot the A500 device, it also provides
a common register read/write API that will be used by the sub-devices.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/mfd/Kconfig        |  11 ++
 drivers/mfd/Makefile       |   1 +
 drivers/mfd/acer-ec-a500.c | 202 +++++++++++++++++++++++++++++++++++++
 3 files changed, 214 insertions(+)
 create mode 100644 drivers/mfd/acer-ec-a500.c

Comments

Lee Jones Jan. 14, 2021, 1:47 p.m. UTC | #1
On Mon, 28 Dec 2020, Dmitry Osipenko wrote:

> Acer Iconia Tab A500 is an Android tablet device, it has ENE KB930

> Embedded Controller which provides battery-gauge, LED, GPIO and some

> other functions. The EC uses firmware that is specifically customized

> for Acer A500. This patch adds MFD driver for the Embedded Controller

> which allows to power-off / reboot the A500 device, it also provides

> a common register read/write API that will be used by the sub-devices.

> 

> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>

> ---

>  drivers/mfd/Kconfig        |  11 ++

>  drivers/mfd/Makefile       |   1 +

>  drivers/mfd/acer-ec-a500.c | 202 +++++++++++++++++++++++++++++++++++++

>  3 files changed, 214 insertions(+)

>  create mode 100644 drivers/mfd/acer-ec-a500.c


Looks good to me:

For my own reference (apply this as-is to your sign-off block):

  Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org>

Do you have a merge plan?

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
Dmitry Osipenko Jan. 14, 2021, 2:12 p.m. UTC | #2
14.01.2021 16:47, Lee Jones пишет:
> On Mon, 28 Dec 2020, Dmitry Osipenko wrote:
> 
>> Acer Iconia Tab A500 is an Android tablet device, it has ENE KB930
>> Embedded Controller which provides battery-gauge, LED, GPIO and some
>> other functions. The EC uses firmware that is specifically customized
>> for Acer A500. This patch adds MFD driver for the Embedded Controller
>> which allows to power-off / reboot the A500 device, it also provides
>> a common register read/write API that will be used by the sub-devices.
>>
>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
>> ---
>>  drivers/mfd/Kconfig        |  11 ++
>>  drivers/mfd/Makefile       |   1 +
>>  drivers/mfd/acer-ec-a500.c | 202 +++++++++++++++++++++++++++++++++++++
>>  3 files changed, 214 insertions(+)
>>  create mode 100644 drivers/mfd/acer-ec-a500.c
> 
> Looks good to me:
> 
> For my own reference (apply this as-is to your sign-off block):
> 
>   Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org>
> 
> Do you have a merge plan?
> 

Thanks, you could take the DT binding and the MFD patches into the MFD
tree right now.

Perhaps will be better to merge the battery patch via the Power tree
since it doesn't have build dependency on the MFD patch. The battery
patch was reviewed by Sebastian, but not acked, as I see now.

Sebastian, could you please take the battery patch?
Lee Jones Jan. 14, 2021, 2:28 p.m. UTC | #3
On Mon, 28 Dec 2020, Dmitry Osipenko wrote:

> Acer Iconia Tab A500 is an Android tablet device, it has ENE KB930
> Embedded Controller which provides battery-gauge, LED, GPIO and some
> other functions. The EC uses firmware that is specifically customized
> for Acer A500. This patch adds MFD driver for the Embedded Controller
> which allows to power-off / reboot the A500 device, it also provides
> a common register read/write API that will be used by the sub-devices.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  drivers/mfd/Kconfig        |  11 ++
>  drivers/mfd/Makefile       |   1 +
>  drivers/mfd/acer-ec-a500.c | 202 +++++++++++++++++++++++++++++++++++++
>  3 files changed, 214 insertions(+)
>  create mode 100644 drivers/mfd/acer-ec-a500.c

Applied, thanks.
diff mbox series

Patch

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index bdfce7b15621..750709219e00 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -2085,6 +2085,17 @@  config MFD_KHADAS_MCU
 	  additional drivers must be enabled in order to use the functionality
 	  of the device.
 
+config MFD_ACER_A500_EC
+	tristate "Support for Acer Iconia Tab A500 Embedded Controller"
+	depends on I2C
+	depends on (ARCH_TEGRA_2x_SOC && OF) || COMPILE_TEST
+	select MFD_CORE
+	select REGMAP
+	help
+	  Support for Embedded Controller found on Acer Iconia Tab A500.
+	  The controller itself is ENE KB930, it is running firmware
+	  customized for the specific needs of the Acer A500 hardware.
+
 menu "Multimedia Capabilities Port drivers"
 	depends on ARCH_SA1100
 
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 14fdb188af02..025543418835 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -264,6 +264,7 @@  obj-$(CONFIG_MFD_ROHM_BD71828)	+= rohm-bd71828.o
 obj-$(CONFIG_MFD_ROHM_BD718XX)	+= rohm-bd718x7.o
 obj-$(CONFIG_MFD_STMFX) 	+= stmfx.o
 obj-$(CONFIG_MFD_KHADAS_MCU) 	+= khadas-mcu.o
+obj-$(CONFIG_MFD_ACER_A500_EC)	+= acer-ec-a500.o
 
 obj-$(CONFIG_SGI_MFD_IOC3)	+= ioc3.o
 obj-$(CONFIG_MFD_SIMPLE_MFD_I2C)	+= simple-mfd-i2c.o
diff --git a/drivers/mfd/acer-ec-a500.c b/drivers/mfd/acer-ec-a500.c
new file mode 100644
index 000000000000..80c2fdd14fc4
--- /dev/null
+++ b/drivers/mfd/acer-ec-a500.c
@@ -0,0 +1,202 @@ 
+// 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;
+}
+
+static int 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);
+	}
+
+	return 0;
+}
+
+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");