Commit 17a924bf authored by Hans de Goede's avatar Hans de Goede Committed by Wolfram Sang
Browse files

i2c-cht-wc: Add Intel Cherry Trail Whiskey Cove SMBUS controller driver 



The Intel Cherry Trail Whiskey Cove PMIC does not contain a builtin
battery charger, instead boards with this PMIC use an external TI
bq24292i charger IC, which is connected to a SMBUS controller built into
the PMIC.

This commit adds an i2c-bus driver for the PMIC's builtin SMBUS
controller. The probe function for this i2c-bus will also register an
i2c-client for the TI bq24292i charger after the i2c-bus has been
registered.

Note that several device-properties are set on the client-device to
tell the bq24190 power-supply driver to integrate the Whiskey Cove PMIC
and e.g. use the PMIC's BC1.2 detection (through extcon) to determine
the maximum input current.

Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent 0a1c7959

drivers/i2c/busses/Kconfig

+8 −0
Original line number Diff line number Diff line
@@ -189,6 +189,14 @@ config I2C_PIIX4 
	  This driver can also be built as a module.  If so, the module

	  will be called i2c-piix4.



config I2C_CHT_WC

	tristate "Intel Cherry Trail Whiskey Cove PMIC smbus controller"

	depends on INTEL_SOC_PMIC_CHTWC

	help

	  If you say yes to this option, support will be included for the

	  SMBus controller found in the Intel Cherry Trail Whiskey Cove PMIC

	  found on some Intel Cherry Trail systems.



config I2C_NFORCE2

	tristate "Nvidia nForce2, nForce3 and nForce4"

	depends on PCI

drivers/i2c/busses/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ obj-$(CONFIG_I2C_ALI15X3) += i2c-ali15x3.o 
obj-$(CONFIG_I2C_AMD756)	+= i2c-amd756.o

obj-$(CONFIG_I2C_AMD756_S4882)	+= i2c-amd756-s4882.o

obj-$(CONFIG_I2C_AMD8111)	+= i2c-amd8111.o

obj-$(CONFIG_I2C_CHT_WC)	+= i2c-cht-wc.o

obj-$(CONFIG_I2C_I801)		+= i2c-i801.o

obj-$(CONFIG_I2C_ISCH)		+= i2c-isch.o

obj-$(CONFIG_I2C_ISMT)		+= i2c-ismt.o

drivers/i2c/busses/i2c-cht-wc.c

0 → 100644
+337 −0
Original line number Diff line number Diff line 
/*

 * Intel CHT Whiskey Cove PMIC I2C Master driver

 * Copyright (C) 2017 Hans de Goede <hdegoede@redhat.com>

 *

 * Based on various non upstream patches to support the CHT Whiskey Cove PMIC:

 * Copyright (C) 2011 - 2014 Intel Corporation. All rights reserved.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License version

 * 2 as published by the Free Software Foundation, or (at your option)

 * any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */



#include <linux/completion.h>

#include <linux/delay.h>

#include <linux/i2c.h>

#include <linux/interrupt.h>

#include <linux/irq.h>

#include <linux/irqdomain.h>

#include <linux/mfd/intel_soc_pmic.h>

#include <linux/module.h>

#include <linux/platform_device.h>

#include <linux/slab.h>



#define CHT_WC_I2C_CTRL			0x5e24

#define CHT_WC_I2C_CTRL_WR		BIT(0)

#define CHT_WC_I2C_CTRL_RD		BIT(1)

#define CHT_WC_I2C_CLIENT_ADDR		0x5e25

#define CHT_WC_I2C_REG_OFFSET		0x5e26

#define CHT_WC_I2C_WRDATA		0x5e27

#define CHT_WC_I2C_RDDATA		0x5e28



#define CHT_WC_EXTCHGRIRQ		0x6e0a

#define CHT_WC_EXTCHGRIRQ_CLIENT_IRQ	BIT(0)

#define CHT_WC_EXTCHGRIRQ_WRITE_IRQ	BIT(1)

#define CHT_WC_EXTCHGRIRQ_READ_IRQ	BIT(2)

#define CHT_WC_EXTCHGRIRQ_NACK_IRQ	BIT(3)

#define CHT_WC_EXTCHGRIRQ_ADAP_IRQMASK	((u8)GENMASK(3, 1))

#define CHT_WC_EXTCHGRIRQ_MSK		0x6e17



struct cht_wc_i2c_adap {

	struct i2c_adapter adapter;

	wait_queue_head_t wait;

	struct irq_chip irqchip;

	struct mutex irqchip_lock;

	struct regmap *regmap;

	struct irq_domain *irq_domain;

	struct i2c_client *client;

	int client_irq;

	u8 irq_mask;

	u8 old_irq_mask;

	bool nack;

	bool done;

};



static irqreturn_t cht_wc_i2c_adap_thread_handler(int id, void *data)

{

	struct cht_wc_i2c_adap *adap = data;

	int ret, reg;



	/* Read IRQs */

	ret = regmap_read(adap->regmap, CHT_WC_EXTCHGRIRQ, &reg);

	if (ret) {

		dev_err(&adap->adapter.dev, "Error reading extchgrirq reg\n");

		return IRQ_NONE;

	}



	reg &= ~adap->irq_mask;



	/*

	 * Immediately ack IRQs, so that if new IRQs arrives while we're

	 * handling the previous ones our irq will re-trigger when we're done.

	 */

	ret = regmap_write(adap->regmap, CHT_WC_EXTCHGRIRQ, reg);

	if (ret)

		dev_err(&adap->adapter.dev, "Error writing extchgrirq reg\n");



	/*

	 * Do NOT use handle_nested_irq here, the client irq handler will

	 * likely want to do i2c transfers and the i2c controller uses this

	 * interrupt handler as well, so running the client irq handler from

	 * this thread will cause things to lock up.

	 */

	if (reg & CHT_WC_EXTCHGRIRQ_CLIENT_IRQ) {

		/*

		 * generic_handle_irq expects local IRQs to be disabled

		 * as normally it is called from interrupt context.

		 */

		local_irq_disable();

		generic_handle_irq(adap->client_irq);

		local_irq_enable();

	}



	if (reg & CHT_WC_EXTCHGRIRQ_ADAP_IRQMASK) {

		adap->nack = !!(reg & CHT_WC_EXTCHGRIRQ_NACK_IRQ);

		adap->done = true;

		wake_up(&adap->wait);

	}



	return IRQ_HANDLED;

}



static u32 cht_wc_i2c_adap_master_func(struct i2c_adapter *adap)

{

	/* This i2c adapter only supports SMBUS byte transfers */

	return I2C_FUNC_SMBUS_BYTE_DATA;

}



static int cht_wc_i2c_adap_smbus_xfer(struct i2c_adapter *_adap, u16 addr,

				      unsigned short flags, char read_write,

				      u8 command, int size,

				      union i2c_smbus_data *data)

{

	struct cht_wc_i2c_adap *adap = i2c_get_adapdata(_adap);

	int ret, reg;



	adap->nack = false;

	adap->done = false;



	ret = regmap_write(adap->regmap, CHT_WC_I2C_CLIENT_ADDR, addr);

	if (ret)

		return ret;



	if (read_write == I2C_SMBUS_WRITE) {

		ret = regmap_write(adap->regmap, CHT_WC_I2C_WRDATA, data->byte);

		if (ret)

			return ret;

	}



	ret = regmap_write(adap->regmap, CHT_WC_I2C_REG_OFFSET, command);

	if (ret)

		return ret;



	ret = regmap_write(adap->regmap, CHT_WC_I2C_CTRL,

			   (read_write == I2C_SMBUS_WRITE) ?

			   CHT_WC_I2C_CTRL_WR : CHT_WC_I2C_CTRL_RD);

	if (ret)

		return ret;



	/* 3 second timeout, during cable plug the PMIC responds quite slow */

	ret = wait_event_timeout(adap->wait, adap->done, 3 * HZ);

	if (ret == 0)

		return -ETIMEDOUT;

	if (adap->nack)

		return -EIO;



	if (read_write == I2C_SMBUS_READ) {

		ret = regmap_read(adap->regmap, CHT_WC_I2C_RDDATA, &reg);

		if (ret)

			return ret;



		data->byte = reg;

	}



	return 0;

}



static const struct i2c_algorithm cht_wc_i2c_adap_algo = {

	.functionality = cht_wc_i2c_adap_master_func,

	.smbus_xfer = cht_wc_i2c_adap_smbus_xfer,

};



/**** irqchip for the client connected to the extchgr i2c adapter ****/

static void cht_wc_i2c_irq_lock(struct irq_data *data)

{

	struct cht_wc_i2c_adap *adap = irq_data_get_irq_chip_data(data);



	mutex_lock(&adap->irqchip_lock);

}



static void cht_wc_i2c_irq_sync_unlock(struct irq_data *data)

{

	struct cht_wc_i2c_adap *adap = irq_data_get_irq_chip_data(data);

	int ret;



	if (adap->irq_mask != adap->old_irq_mask) {

		ret = regmap_write(adap->regmap, CHT_WC_EXTCHGRIRQ_MSK,

				   adap->irq_mask);

		if (ret == 0)

			adap->old_irq_mask = adap->irq_mask;

		else

			dev_err(&adap->adapter.dev, "Error writing EXTCHGRIRQ_MSK\n");

	}



	mutex_unlock(&adap->irqchip_lock);

}



static void cht_wc_i2c_irq_enable(struct irq_data *data)

{

	struct cht_wc_i2c_adap *adap = irq_data_get_irq_chip_data(data);



	adap->irq_mask &= ~CHT_WC_EXTCHGRIRQ_CLIENT_IRQ;

}



static void cht_wc_i2c_irq_disable(struct irq_data *data)

{

	struct cht_wc_i2c_adap *adap = irq_data_get_irq_chip_data(data);



	adap->irq_mask |= CHT_WC_EXTCHGRIRQ_CLIENT_IRQ;

}



static const struct irq_chip cht_wc_i2c_irq_chip = {

	.irq_bus_lock		= cht_wc_i2c_irq_lock,

	.irq_bus_sync_unlock	= cht_wc_i2c_irq_sync_unlock,

	.irq_disable		= cht_wc_i2c_irq_disable,

	.irq_enable		= cht_wc_i2c_irq_enable,

	.name			= "cht_wc_ext_chrg_irq_chip",

};



static const struct property_entry bq24190_props[] = {

	PROPERTY_ENTRY_STRING("extcon-name", "cht_wcove_pwrsrc"),

	PROPERTY_ENTRY_BOOL("omit-battery-class"),

	PROPERTY_ENTRY_BOOL("disable-reset"),

	{ }

};



static int cht_wc_i2c_adap_i2c_probe(struct platform_device *pdev)

{

	struct intel_soc_pmic *pmic = dev_get_drvdata(pdev->dev.parent);

	struct cht_wc_i2c_adap *adap;

	struct i2c_board_info board_info = {

		.type = "bq24190",

		.addr = 0x6b,

		.properties = bq24190_props,

	};

	int ret, irq;



	irq = platform_get_irq(pdev, 0);

	if (irq < 0) {

		dev_err(&pdev->dev, "Error missing irq resource\n");

		return -EINVAL;

	}



	adap = devm_kzalloc(&pdev->dev, sizeof(*adap), GFP_KERNEL);

	if (!adap)

		return -ENOMEM;



	init_waitqueue_head(&adap->wait);

	mutex_init(&adap->irqchip_lock);

	adap->irqchip = cht_wc_i2c_irq_chip;

	adap->regmap = pmic->regmap;

	adap->adapter.owner = THIS_MODULE;

	adap->adapter.class = I2C_CLASS_HWMON;

	adap->adapter.algo = &cht_wc_i2c_adap_algo;

	strlcpy(adap->adapter.name, "PMIC I2C Adapter",

		sizeof(adap->adapter.name));

	adap->adapter.dev.parent = &pdev->dev;



	/* Clear and activate i2c-adapter interrupts, disable client IRQ */

	adap->old_irq_mask = adap->irq_mask = ~CHT_WC_EXTCHGRIRQ_ADAP_IRQMASK;

	ret = regmap_write(adap->regmap, CHT_WC_EXTCHGRIRQ, ~adap->irq_mask);

	if (ret)

		return ret;



	ret = regmap_write(adap->regmap, CHT_WC_EXTCHGRIRQ_MSK, adap->irq_mask);

	if (ret)

		return ret;



	/* Alloc and register client IRQ */

	adap->irq_domain = irq_domain_add_linear(pdev->dev.of_node, 1,

						 &irq_domain_simple_ops, NULL);

	if (!adap->irq_domain)

		return -ENOMEM;



	adap->client_irq = irq_create_mapping(adap->irq_domain, 0);

	if (!adap->client_irq) {

		ret = -ENOMEM;

		goto remove_irq_domain;

	}



	irq_set_chip_data(adap->client_irq, adap);

	irq_set_chip_and_handler(adap->client_irq, &adap->irqchip,

				 handle_simple_irq);



	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,

					cht_wc_i2c_adap_thread_handler,

					IRQF_ONESHOT, "PMIC I2C Adapter", adap);

	if (ret)

		goto remove_irq_domain;



	i2c_set_adapdata(&adap->adapter, adap);

	ret = i2c_add_adapter(&adap->adapter);

	if (ret)

		goto remove_irq_domain;



	board_info.irq = adap->client_irq;

	adap->client = i2c_new_device(&adap->adapter, &board_info);

	if (!adap->client) {

		ret = -ENOMEM;

		goto del_adapter;

	}



	platform_set_drvdata(pdev, adap);

	return 0;



del_adapter:

	i2c_del_adapter(&adap->adapter);

remove_irq_domain:

	irq_domain_remove(adap->irq_domain);

	return ret;

}



static int cht_wc_i2c_adap_i2c_remove(struct platform_device *pdev)

{

	struct cht_wc_i2c_adap *adap = platform_get_drvdata(pdev);



	i2c_unregister_device(adap->client);

	i2c_del_adapter(&adap->adapter);

	irq_domain_remove(adap->irq_domain);



	return 0;

}



static struct platform_device_id cht_wc_i2c_adap_id_table[] = {

	{ .name = "cht_wcove_ext_chgr" },

	{},

};

MODULE_DEVICE_TABLE(platform, cht_wc_i2c_adap_id_table);



struct platform_driver cht_wc_i2c_adap_driver = {

	.probe = cht_wc_i2c_adap_i2c_probe,

	.remove = cht_wc_i2c_adap_i2c_remove,

	.driver = {

		.name = "cht_wcove_ext_chgr",

	},

	.id_table = cht_wc_i2c_adap_id_table,

};

module_platform_driver(cht_wc_i2c_adap_driver);



MODULE_DESCRIPTION("Intel CHT Whiskey Cove PMIC I2C Master driver");

MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");

MODULE_LICENSE("GPL");

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