[PATCH 15/15] i2c-cht-wc: Add Intel Cherry Trail Whiskey Cove SMBUS controller driver

Hans de Goede
2017-03-17T09:56:49Z

The Intel Cherry Trail Whiskey Cove PMIC has a builtin SMBUS controller
for talking to an external PMIC. Add a driver for this.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
drivers/i2c/busses/Kconfig | 9 ++
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-cht-wc.c | 338 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 348 insertions(+)
create mode 100644 drivers/i2c/busses/i2c-cht-wc.c

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 8adc0f1..19ddd82 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -187,6 +187,15 @@ 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
+ depends on CHT_WC_FUEL_GAUGE
+ 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
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 30b6085..f6443fa 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -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
diff --git a/drivers/i2c/busses/i2c-cht-wc.c b/drivers/i2c/busses/i2c-cht-wc.c
new file mode 100644
index 0000000..70599f7
--- /dev/null
+++ b/drivers/i2c/busses/i2c-cht-wc.c
@@ -0,0 +1,338 @@
+/*
+ * 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.
+ *
+ * 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/power/bq24190_charger.h>
+#include <linux/power/cht_wc_fuel_gauge.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_IRQS ((u8)(BIT(1) | BIT(2) | BIT(3)))
+#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_IRQS) {
+ if (reg & CHT_WC_EXTCHGRIRQ_NACK_IRQ)
+ adap->nack = true;
+ 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, HZ * 3);
+ 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 bq24190_platform_data bq24190_pdata = {
+ .no_register_reset = true,
+ .extcon_name = "cht_wcove_pwrsrc",
+ .get_ext_bat_property = cht_wc_fg_get_property,
+};
+
+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,
+ .platform_data = (void *)&bq24190_pdata,
+ };
+ 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_IRQS;
+ 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");
--
2.9.3