Re: [PATCH 1/3] mfd: add STMPE811 core support

Jonathan Cameron
2010-06-11T11:04:27Z

On 06/11/10 11:13, Luotao Fu wrote:

Hi couple of really minor comments inline.

Looks good to me,

Acked-by: Jonathan Cameron<jic23@cam.ac.uk>

> STMPE811 is a multifunction device, which contains a GPIO controller, a
> Touchscreen controller, an ADC and a temperature sensor. This patch adds a core
> driver for this device. The driver provides core functionalities like accessing
> the registers and management of subdevices. The device supports communication
> through SPI and I2C interface. Currently we only support I2C.
>
> Signed-off-by: Luotao Fu <l.fu@pengutronix.de>
> ---
> drivers/mfd/Kconfig | 8 +
> drivers/mfd/Makefile | 1 +
> drivers/mfd/stmpe811-core.c | 369 ++++++++++++++++++++++++++++++++++++++++++
> include/linux/mfd/stmpe811.h | 126 ++++++++++++++
> 4 files changed, 504 insertions(+), 0 deletions(-)
> create mode 100644 drivers/mfd/stmpe811-core.c
> create mode 100644 include/linux/mfd/stmpe811.h
>
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index 9da0e50..2c5388b 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -482,6 +482,14 @@ config MFD_JANZ_CMODIO
> host many different types of MODULbus daughterboards, including
> CAN and GPIO controllers.
>
> +config MFD_STMPE811
> + tristate "STMicroelectronics STMPE811"
> + depends on I2C
> + select MFD_CORE
> + help
> + This is the core driver for the stmpe811 GPIO expander with touchscreen
> + controller, ADC and temperature sensor.
> +
> endif # MFD_SUPPORT
>
> menu "Multimedia Capabilities Port drivers"
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index fb503e7..6a7ad83 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -71,3 +71,4 @@ obj-$(CONFIG_PMIC_ADP5520) += adp5520.o
> obj-$(CONFIG_LPC_SCH) += lpc_sch.o
> obj-$(CONFIG_MFD_RDC321X) += rdc321x-southbridge.o
> obj-$(CONFIG_MFD_JANZ_CMODIO) += janz-cmodio.o
> +obj-$(CONFIG_MFD_STMPE811) += stmpe811-core.o
> diff --git a/drivers/mfd/stmpe811-core.c b/drivers/mfd/stmpe811-core.c
> new file mode 100644
> index 0000000..080b3d7
> --- /dev/null
> +++ b/drivers/mfd/stmpe811-core.c
> @@ -0,0 +1,369 @@
> +/*
> + * stmpe811-core.c -- core support for STMicroelectronics STMPE811 chip.
> + *
> + * based on pcf50633-core.c by Harald Welte <laforge@openmoko.org> and
> + * Balaji Rao <balajirrao@openmoko.org>
> + *
> + * (c)2010 Luotao Fu <l.fu@pengutronix.de>
> + *
> + * 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.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/interrupt.h>
> +#include <linux/slab.h>
> +#include <linux/platform_device.h>
> +#include <linux/i2c.h>
> +#include <linux/mfd/core.h>
> +#include <linux/mfd/stmpe811.h>
> +
> +static inline int __stmpe811_i2c_reads(struct i2c_client *client, int reg,
> + int len, u8 *val)
> +{
> + int ret;
> +
> + ret = i2c_smbus_read_i2c_block_data(client, reg, len, val);
> + if (ret < 0) {
> + dev_err(&client->dev, "failed reading from 0x%02x\n", reg);
> + return ret;
> + }
> + return 0;
> +}
> +
> +static struct mfd_cell stmpe811_ts_dev = {
> + .name = "stmpe811-ts",
> +};
> +
> +static struct mfd_cell stmpe811_gpio_dev = {
> + .name = "stmpe811-gpio",
> +};
> +
> +static void stmpe811_irq_worker(struct work_struct *work)
> +{
> + struct stmpe811 *stm;
> + int ret, bit;
> + u8 int_stat;
> + irq_handler_t handler;
> + void *data;
> +
> + stm = container_of(work, struct stmpe811, irq_work);
> +
> + ret = stmpe811_reg_read(stm, STMPE811_REG_INT_STA, &int_stat);
> + if (ret) {
> + dev_err(stm->dev, "Error reading INT registers\n");
> + goto out;
> + }
> +
> + dev_dbg(stm->dev, "%s int_stat 0x%02x\n", __func__, int_stat);
> +
> + for_each_set_bit(bit, (unsigned long *)&int_stat, STMPE811_NUM_IRQ) {
> + handler = stm->irqhandler[bit];
> + data = stm->irqdata[bit];
> + if (handler) {
> + /* mask the interrupt while calling handler */
> + stmpe811_reg_clear_bits(stm, STMPE811_REG_INT_EN,
> + 1 << bit);
> + /* call handler and acknowledge the interrupt */
> + handler(bit, data);
> + stmpe811_reg_set_bits(stm, STMPE811_REG_INT_STA,
> + (1 << bit));
small formatting quirk. Why the brackets in the above?
> + /* demask the interrupt */
> + stmpe811_reg_set_bits(stm, STMPE811_REG_INT_EN,
> + 1 << bit);
> + }
> + }
> +out:
> + put_device(stm->dev);
> + enable_irq(stm->irq);
> +
bonus white line.
> +}
> +
> +static irqreturn_t stmpe811_irq(int irq, void *data)
> +{
> + struct stmpe811 *stm = data;
> +
> + get_device(stm->dev);
> + disable_irq_nosync(stm->irq);
> + queue_work(stm->work_queue, &stm->irq_work);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static inline int __stmpe811_i2c_read(struct i2c_client *client,
> + int reg, u8 *val)
> +{
> + int ret;
> +
> + ret = i2c_smbus_read_byte_data(client, reg);
> + if (ret < 0) {
> + dev_err(&client->dev, "failed reading at 0x%02x\n", reg);
> + return ret;
> + }
> + dev_dbg(&client->dev, "%s: value 0x%x from 0x%x\n", __func__, ret, reg);
> +
> + *val = (u8) ret;
> + return 0;
> +}
> +
> +static inline int __stmpe811_i2c_write(struct i2c_client *client,
> + int reg, u8 val)
> +{
> + int ret;
> +
> + ret = i2c_smbus_write_byte_data(client, reg, val);
> + if (ret < 0) {
> + dev_err(&client->dev, "failed writing 0x%02x to 0x%02x\n",
> + val, reg);
> + return ret;
> + }
> + return 0;
> +}
> +
> +int stmpe811_block_read(struct stmpe811 *stm, u8 reg, uint len, u8 *val)
> +{
> + int ret;
> +
> + mutex_lock(&stm->io_lock);
> + ret = __stmpe811_i2c_reads(stm->i2c_client, reg, len, val);
> + mutex_unlock(&stm->io_lock);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(stmpe811_block_read);
> +
> +int stmpe811_reg_read(struct stmpe811 *stm, u8 reg, u8 *val)
> +{
> + int ret;
> +
> + mutex_lock(&stm->io_lock);
> + ret = __stmpe811_i2c_read(stm->i2c_client, reg, val);
> + mutex_unlock(&stm->io_lock);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(stmpe811_reg_read);
> +
> +int stmpe811_reg_write(struct stmpe811 *stm, u8 reg, u8 val)
> +{
> + int ret;
> +
> + mutex_lock(&stm->io_lock);
> + ret = __stmpe811_i2c_write(stm->i2c_client, reg, val);
> + mutex_unlock(&stm->io_lock);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(stmpe811_reg_write);
> +
> +int stmpe811_reg_set_bits(struct stmpe811 *stm, u8 reg, u8 val)
> +{
> + int ret;
> + u8 tmp;
> +
> + mutex_lock(&stm->io_lock);
> + ret = __stmpe811_i2c_read(stm->i2c_client, reg, &tmp);
> + if (ret < 0)
> + goto out;
> +
> + tmp |= val;
> + ret = __stmpe811_i2c_write(stm->i2c_client, reg, tmp);
> +
> +out:
> + mutex_unlock(&stm->io_lock);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(stmpe811_reg_set_bits);
> +
> +int stmpe811_reg_clear_bits(struct stmpe811 *stm, u8 reg, u8 val)
> +{
> + int ret;
> + u8 tmp;
> +
> + mutex_lock(&stm->io_lock);
> + ret = __stmpe811_i2c_read(stm->i2c_client, reg, &tmp);
> + if (ret < 0)
> + goto out;
> +
> + tmp &= ~val;
> + ret = __stmpe811_i2c_write(stm->i2c_client, reg, tmp);
> +
> +out:
> + mutex_unlock(&stm->io_lock);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(stmpe811_reg_clear_bits);
> +
> +int stmpe811_register_irq(struct stmpe811 *stm, int irq,
> + irq_handler_t handler, void *data)
> +{
> + if (irq < 0 || irq > STMPE811_NUM_IRQ || !handler)
> + return -EINVAL;
> +
> + if (WARN_ON(stm->irqhandler[irq]))
> + return -EBUSY;
> +
> + stm->irqhandler[irq] = handler;
> + stm->irqdata[irq] = data;
> + /* unmask the irq */
> + return stmpe811_reg_set_bits(stm, STMPE811_REG_INT_EN, 1 << irq);
> +}
> +EXPORT_SYMBOL_GPL(stmpe811_register_irq);
> +
> +int stmpe811_free_irq(struct stmpe811 *stm, int irq)
> +{
> + if (irq < 0 || irq > STMPE811_NUM_IRQ)
> + return -EINVAL;
> +
> + stm->irqhandler[irq] = NULL;
> +
> + return stmpe811_reg_clear_bits(stm, STMPE811_REG_INT_EN, 1 << irq);
> +}
> +EXPORT_SYMBOL_GPL(stmpe811_free_irq);
> +
> +static int __devinit stmpe811_probe(struct i2c_client *client,
> + const struct i2c_device_id *ids)
> +{
> + struct stmpe811 *stm;
> + struct stmpe811_platform_data *pdata = client->dev.platform_data;
> + int ret = 0;
> + u8 chip_id[2], chip_ver = 0;
> +
> + if (!client->irq) {
> + dev_err(&client->dev, "Missing IRQ\n");
> + return -ENOENT;
> + }
> +
> + stm = kzalloc(sizeof(*stm), GFP_KERNEL);
> + if (!stm)
> + return -ENOMEM;
> +
> + stm->pdata = pdata;
> +
> + mutex_init(&stm->io_lock);
> +
> + i2c_set_clientdata(client, stm);
> + stm->dev = &client->dev;
> + stm->i2c_client = client;
> + stm->irq = client->irq;
> + stm->work_queue = create_singlethread_workqueue("stmpe811");
> +
> + if (!stm->work_queue) {
> + dev_err(&client->dev, "Failed to alloc workqueue\n");
> + ret = -ENOMEM;
> + goto err_free;
> + }
> +
> + INIT_WORK(&stm->irq_work, stmpe811_irq_worker);
> +
> + ret = stmpe811_block_read(stm, STMPE811_REG_CHIP_ID, 2, chip_id);
> + if ((ret < 0) || (((chip_id[0] << 8) | chip_id[1]) != 0x811)) {
> + dev_err(&client->dev, "could not verify stmpe811 chip id\n");
> + ret = -ENODEV;
> + goto err_destroy_workqueue;
> + }
> +
> + stmpe811_reg_read(stm, STMPE811_REG_ID_VER, &chip_ver);
> + dev_info(&client->dev, "found stmpe811 chip id 0x%x version 0x%x\n",
> + (chip_id[0] << 8) | chip_id[1], chip_ver);
> +
> + /* reset the device */
> + stmpe811_reg_write(stm, STMPE811_REG_SYS_CTRL1,
> + STMPE811_SYS_CTRL1_SOFT_RESET);
> +
> + /* setup platform specific interrupt control flags and enable global
> + * interrupt */
> + stmpe811_reg_write(stm, STMPE811_REG_INT_CTRL,
> + STMPE811_INT_CTRL_GLOBAL_INT | pdata->int_conf);
> + ret =
> + request_irq(client->irq, stmpe811_irq, pdata->irq_flags, "stmpe811",
> + stm);
> + if (ret) {
> + dev_err(stm->dev, "Failed to request IRQ %d\n", ret);
> + goto err_destroy_workqueue;
> + }
> +
> + if (pdata->flags & STMPE811_USE_TS)
> + ret =
> + mfd_add_devices(&client->dev, -1, &stmpe811_ts_dev, 1, NULL,
> + 0);
> + if (ret != 0)
> + goto err_release_irq;
> +
> + if (pdata->flags & STMPE811_USE_GPIO)
> + ret =
> + mfd_add_devices(&client->dev, -1, &stmpe811_gpio_dev, 1,
> + NULL, 0);
> + if (ret != 0)
> + goto err_remove_mfd_devices;
> +
> + return ret;
> +
> +err_remove_mfd_devices:
> + mfd_remove_devices(&client->dev);
> +err_release_irq:
> + free_irq(client->irq, stm);
> +err_destroy_workqueue:
> + destroy_workqueue(stm->work_queue);
> +err_free:
> + mutex_destroy(&stm->io_lock);
> + i2c_set_clientdata(client, NULL);
> + kfree(stm);
> +
> + return ret;
> +}
> +
> +static int __devexit stmpe811_remove(struct i2c_client *client)
> +{
> + struct stmpe811 *stm = i2c_get_clientdata(client);
> +
> + stmpe811_reg_write(stm, STMPE811_REG_SYS_CTRL1,
> + STMPE811_SYS_CTRL1_HIBERNATE);
> +
> + free_irq(stm->irq, stm);
> + destroy_workqueue(stm->work_queue);
> +
> + mfd_remove_devices(&client->dev);
> +
> + kfree(stm);
> +
> + return 0;
> +}
> +
> +static struct i2c_device_id stmpe811_id_table[] = {
> + {"stmpe811", 0x88},
> + { /* end of list */ }
> +};
> +
> +static struct i2c_driver stmpe811_driver = {
> + .driver = {
> + .name = "stmpe811",
> + .owner = THIS_MODULE,
> + },
> + .probe = stmpe811_probe,
> + .remove = __devexit_p(stmpe811_remove),
> + .id_table = stmpe811_id_table,
> +};
> +
> +static int __init stmpe811_init(void)
> +{
> + return i2c_add_driver(&stmpe811_driver);
> +}
> +
> +subsys_initcall(stmpe811_init);
> +
> +static void __exit stmpe811_exit(void)
> +{
> + i2c_del_driver(&stmpe811_driver);
> +}
> +
> +module_exit(stmpe811_exit);
> +
> +MODULE_DESCRIPTION
> + ("CORE Driver for STMPE811 Touch screen controller with GPIO expander");
> +MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/mfd/stmpe811.h b/include/linux/mfd/stmpe811.h
> new file mode 100644
> index 0000000..ab2808a
> --- /dev/null
> +++ b/include/linux/mfd/stmpe811.h
> @@ -0,0 +1,126 @@
> +#ifndef __LINUX_MFD_STMPE811_H
> +#define __LINUX_MFD_STMPE811_H
> +
> +#include <linux/i2c.h>
> +#include <linux/workqueue.h>
> +

Personally I'd be inclined to put these in the
subdevice drivers that care about them.

Just keep the ones used by multiple subdevices
in here...

> +#define STMPE811_REG_CHIP_ID 0x00
> +#define STMPE811_REG_ID_VER 0x02
> +#define STMPE811_REG_SYS_CTRL1 0x03
> +#define STMPE811_REG_SYS_CTRL2 0x04
> +#define STMPE811_REG_SPI_CFG 0x08
> +#define STMPE811_REG_INT_CTRL 0x09
> +#define STMPE811_REG_INT_EN 0x0A
> +#define STMPE811_REG_INT_STA 0x0B
> +#define STMPE811_REG_GPIO_EN 0x0C
> +#define STMPE811_REG_GPIO_INT_STA 0x0D
> +#define STMPE811_REG_ADC_INT_EN 0x0E
> +#define STMPE811_REG_ADC_INT_STA 0x0F
> +#define STMPE811_REG_GPIO_SET_PIN 0x10
> +#define STMPE811_REG_GPIO_CLR_PIN 0x11
> +#define STMPE811_REG_GPIO_MP_STA 0x12
> +#define STMPE811_REG_GPIO_DIR 0x13
> +#define STMPE811_REG_GPIO_ED 0x14
> +#define STMPE811_REG_GPIO_RE 0x15
> +#define STMPE811_REG_GPIO_FE 0x16
> +#define STMPE811_REG_GPIO_AF 0x17
> +#define STMPE811_REG_ADC_CTRL1 0x20
> +#define STMPE811_REG_ADC_CTRL2 0x21
> +#define STMPE811_REG_ADC_CAPT 0x22
> +#define STMPE811_REG_ADC_DATA_CH0 0x30
> +#define STMPE811_REG_ADC_DATA_CH1 0x32
> +#define STMPE811_REG_ADC_DATA_CH2 0x34
> +#define STMPE811_REG_ADC_DATA_CH3 0x36
> +#define STMPE811_REG_ADC_DATA_CH4 0x38
> +#define STMPE811_REG_ADC_DATA_CH5 0x3A
> +#define STMPE811_REG_ADC_DATA_CH6 0x3C
> +#define STMPE811_REG_ADC_DATA_CH7 0x3E
> +#define STMPE811_REG_TSC_CTRL 0x40
> +#define STMPE811_REG_TSC_CFG 0x41
> +#define STMPE811_REG_WDW_TR_X 0x42
> +#define STMPE811_REG_WDW_TR_Y 0x44
> +#define STMPE811_REG_WDW_BL_X 0x46
> +#define STMPE811_REG_WDW_BL_Y 0x48
> +#define STMPE811_REG_FIFO_TH 0x4A
> +#define STMPE811_REG_FIFO_STA 0x4B
> +#define STMPE811_REG_FIFO_SIZE 0x4C
> +#define STMPE811_REG_TSC_DATA_X 0x4D
> +#define STMPE811_REG_TSC_DATA_Y 0x4F
> +#define STMPE811_REG_TSC_DATA_Z 0x51
> +#define STMPE811_REG_TSC_DATA_XYZ 0x52
> +#define STMPE811_REG_TSC_FRACTION_Z 0x56
> +#define STMPE811_REG_TSC_DATA 0x57
> +#define STMPE811_REG_TSC_DATA_SINGLE 0xD7
> +#define STMPE811_REG_TSC_I_DRIVE 0x58
> +#define STMPE811_REG_TSC_SHIELD 0x59
> +#define STMPE811_REG_TEMP_CTRL 0x60
> +
> +#define STMPE811_IRQ_TOUCH_DET 0
> +#define STMPE811_IRQ_FIFO_TH 1
> +#define STMPE811_IRQ_FIFO_OFLOW 2
> +#define STMPE811_IRQ_FIFO_FULL 3
> +#define STMPE811_IRQ_FIFO_EMPTY 4
> +#define STMPE811_IRQ_TEMP_SENS 5
> +#define STMPE811_IRQ_ADC 6
> +#define STMPE811_IRQ_GPIO 7
> +#define STMPE811_NUM_IRQ 8
> +
> +#define STMPE811_SYS_CTRL1_HIBERNATE (1<<0)
> +#define STMPE811_SYS_CTRL1_SOFT_RESET (1<<1)
> +
> +#define STMPE811_SYS_CTRL2_ADC_OFF (1<<0)
> +#define STMPE811_SYS_CTRL2_TSC_OFF (1<<1)
> +#define STMPE811_SYS_CTRL2_GPIO_OFF (1<<2)
> +#define STMPE811_SYS_CTRL2_TS_OFF (1<<3)
> +
> +#define STMPE811_INT_CTRL_GLOBAL_INT (1<<0)
> +#define STMPE811_INT_CTRL_INT_TYPE (1<<1)
> +#define STMPE811_INT_CTRL_INT_POLARITY (1<<2)
> +
> +#define STMPE811_FIFO_STA_OFLOW (1<<7)
> +#define STMPE811_FIFO_STA_FULL (1<<6)
> +#define STMPE811_FIFO_STA_EMPTY (1<<5)
> +#define STMPE811_FIFO_STA_TH_TRIG (1<<4)
> +#define STMPE811_FIFO_STA_RESET (1<<0)
> +
> +#define STMPE811_USE_TS (1<<0)
> +#define STMPE811_USE_GPIO (1<<1)
> +
> +struct stmpe811 {
> + struct device *dev;
> + struct i2c_client *i2c_client;
> +
> + struct stmpe811_platform_data *pdata;
> + int irq;
> + irq_handler_t irqhandler[STMPE811_NUM_IRQ];
> + void *irqdata[STMPE811_NUM_IRQ];
> + struct work_struct irq_work;
> + struct workqueue_struct *work_queue;
> + struct mutex io_lock;
> + u8 active_flag;
> +};
> +
> +struct stmpe811_gpio_platform_data {
> + unsigned int gpio_base;
> + int (*setup) (struct stmpe811 *stm);
> + void (*remove) (struct stmpe811 *stm);
> +};
> +
> +struct stmpe811_platform_data {
> + unsigned int flags;
> + unsigned int irq_flags;
> + unsigned int int_conf;
> + struct stmpe811_gpio_platform_data *gpio_pdata;
> +};
> +
> +int stmpe811_block_read(struct stmpe811 *stm, u8 reg, uint len, u8 *val);
> +int stmpe811_reg_read(struct stmpe811 *pcf, u8 reg, u8 *val);
> +int stmpe811_reg_write(struct stmpe811 *stm, u8 reg, u8 val);
> +int stmpe811_reg_set_bits(struct stmpe811 *stm, u8 reg, u8 val);
> +int stmpe811_reg_clear_bits(struct stmpe811 *stm, u8 reg, u8 val);
> +
> +int stmpe811_register_irq(struct stmpe811 *stm, int irq,
> + irq_handler_t handler, void *data);
> +int stmpe811_free_irq(struct stmpe811 *stm, int irq);
> +
> +#endif