From: David Brownell

This adds basic support for the GPIOs in the twl4030 power management
chip. That includes two open drain LED drivers, and the use of GPIO-0
(and GPIO-1) as MMC/SD card detect switches which can control whether
the VMMC1 (and VMMC2) regulators are active.

This version of the code has a debounce call that will probably be
replaced before long, when a more generic interface exists.

Signed-off-by: David Brownell
Signed-off-by: Tony Lindgren
---
Patch depends on the twl4030-irq patch.

drivers/gpio/Kconfig | 7
drivers/gpio/Makefile | 1
drivers/gpio/twl4030-gpio.c | 521 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 529 insertions(+)

--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -127,6 +127,13 @@ config GPIO_PCF857X
This driver provides an in-kernel interface to those GPIOs using
platform-neutral GPIO calls.

+config GPIO_TWL4030
+ tristate "TWL4030, TWL5030, and TPS659x0 GPIOs"
+ depends on TWL4030_CORE
+ help
+ Say yes here to access the GPIO signals of various multi-function
+ power management chips from Texas Instruments.
+
comment "PCI GPIO expanders:"

config GPIO_BT8XX
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -9,4 +9,5 @@ obj-$(CONFIG_GPIO_MAX732X) += max732x.o
obj-$(CONFIG_GPIO_MCP23S08) += mcp23s08.o
obj-$(CONFIG_GPIO_PCA953X) += pca953x.o
obj-$(CONFIG_GPIO_PCF857X) += pcf857x.o
+obj-$(CONFIG_GPIO_TWL4030) += twl4030-gpio.o
obj-$(CONFIG_GPIO_BT8XX) += bt8xxgpio.o
--- /dev/null
+++ b/drivers/gpio/twl4030-gpio.c
@@ -0,0 +1,521 @@
+/*
+ * twl4030_gpio.c -- access to GPIOs on TWL4030/TPS659x0 chips
+ *
+ * Copyright (C) 2006-2007 Texas Instruments, Inc.
+ * Copyright (C) 2006 MontaVista Software, Inc.
+ *
+ * Code re-arranged and cleaned up by:
+ * Syed Mohammed Khasim
+ *
+ * Initial Code:
+ * Andy Lowe / Nishanth Menon
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+#include
+
+
+/*
+ * The GPIO "subchip" supports 18 GPIOs which can be configured as
+ * inputs or outputs, with pullups or pulldowns on each pin. Each
+ * GPIO can trigger interrupts on either or both edges.
+ *
+ * GPIO interrupts can be fed to either of two IRQ lines; this is
+ * intended to support multiple hosts.
+ *
+ * There are also two LED pins used sometimes as output-only GPIOs.
+ */
+
+
+static struct gpio_chip twl_gpiochip;
+static int twl4030_gpio_irq_base;
+
+/* genirq interfaces are not available to modules */
+#ifdef MODULE
+#define is_module() true
+#else
+#define is_module() false
+#endif
+
+/* GPIO_CTRL Fields */
+#define MASK_GPIO_CTRL_GPIO0CD1 BIT(0)
+#define MASK_GPIO_CTRL_GPIO1CD2 BIT(1)
+#define MASK_GPIO_CTRL_GPIO_ON BIT(2)
+
+/* Mask for GPIO registers when aggregated into a 32-bit integer */
+#define GPIO_32_MASK 0x0003ffff
+
+/* Data structures */
+static DEFINE_MUTEX(gpio_lock);
+
+/* store usage of each GPIO. - each bit represents one GPIO */
+static unsigned int gpio_usage_count;
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * To configure TWL4030 GPIO module registers
+ */
+static inline int gpio_twl4030_write(u8 address, u8 data)
+{
+ return twl4030_i2c_write_u8(TWL4030_MODULE_GPIO, data, address);
+}
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * LED register offsets (use TWL4030_MODULE_{LED,PWMA,PWMB}))
+ * PWMs A and B are dedicated to LEDs A and B, respectively.
+ */
+
+#define TWL4030_LED_LEDEN 0x0
+
+/* LEDEN bits */
+#define LEDEN_LEDAON BIT(0)
+#define LEDEN_LEDBON BIT(1)
+#define LEDEN_LEDAEXT BIT(2)
+#define LEDEN_LEDBEXT BIT(3)
+#define LEDEN_LEDAPWM BIT(4)
+#define LEDEN_LEDBPWM BIT(5)
+#define LEDEN_PWM_LENGTHA BIT(6)
+#define LEDEN_PWM_LENGTHB BIT(7)
+
+#define TWL4030_PWMx_PWMxON 0x0
+#define TWL4030_PWMx_PWMxOFF 0x1
+
+#define PWMxON_LENGTH BIT(7)
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * To read a TWL4030 GPIO module register
+ */
+static inline int gpio_twl4030_read(u8 address)
+{
+ u8 data;
+ int ret = 0;
+
+ ret = twl4030_i2c_read_u8(TWL4030_MODULE_GPIO, &data, address);
+ return (ret < 0) ? ret : data;
+}
+
+/*----------------------------------------------------------------------*/
+
+static u8 cached_leden; /* protected by gpio_lock */
+
+/* The LED lines are open drain outputs ... a FET pulls to GND, so an
+ * external pullup is needed. We could also expose the integrated PWM
+ * as a LED brightness control; we initialize it as "always on".
+ */
+static void twl4030_led_set_value(int led, int value)
+{
+ u8 mask = LEDEN_LEDAON | LEDEN_LEDAPWM;
+ int status;
+
+ if (led)
+ mask <<= 1;
+
+ mutex_lock(&gpio_lock);
+ if (value)
+ cached_leden &= ~mask;
+ else
+ cached_leden |= mask;
+ status = twl4030_i2c_write_u8(TWL4030_MODULE_LED, cached_leden,
+ TWL4030_LED_LEDEN);
+ mutex_unlock(&gpio_lock);
+}
+
+static int twl4030_set_gpio_direction(int gpio, int is_input)
+{
+ u8 d_bnk = gpio >> 3;
+ u8 d_msk = BIT(gpio & 0x7);
+ u8 reg = 0;
+ u8 base = REG_GPIODATADIR1 + d_bnk;
+ int ret = 0;
+
+ mutex_lock(&gpio_lock);
+ ret = gpio_twl4030_read(base);
+ if (ret >= 0) {
+ if (is_input)
+ reg = ret & ~d_msk;
+ else
+ reg = ret | d_msk;
+
+ ret = gpio_twl4030_write(base, reg);
+ }
+ mutex_unlock(&gpio_lock);
+ return ret;
+}
+
+static int twl4030_set_gpio_dataout(int gpio, int enable)
+{
+ u8 d_bnk = gpio >> 3;
+ u8 d_msk = BIT(gpio & 0x7);
+ u8 base = 0;
+
+ if (enable)
+ base = REG_SETGPIODATAOUT1 + d_bnk;
+ else
+ base = REG_CLEARGPIODATAOUT1 + d_bnk;
+
+ return gpio_twl4030_write(base, d_msk);
+}
+
+static int twl4030_get_gpio_datain(int gpio)
+{
+ u8 d_bnk = gpio >> 3;
+ u8 d_off = gpio & 0x7;
+ u8 base = 0;
+ int ret = 0;
+
+ if (unlikely((gpio >= TWL4030_GPIO_MAX)
+ || !(gpio_usage_count & BIT(gpio))))
+ return -EPERM;
+
+ base = REG_GPIODATAIN1 + d_bnk;
+ ret = gpio_twl4030_read(base);
+ if (ret > 0)
+ ret = (ret >> d_off) & 0x1;
+
+ return ret;
+}
+
+/*
+ * Configure debounce timing value for a GPIO pin on TWL4030
+ */
+int twl4030_set_gpio_debounce(int gpio, int enable)
+{
+ u8 d_bnk = gpio >> 3;
+ u8 d_msk = BIT(gpio & 0x7);
+ u8 reg = 0;
+ u8 base = 0;
+ int ret = 0;
+
+ if (unlikely((gpio >= TWL4030_GPIO_MAX)
+ || !(gpio_usage_count & BIT(gpio))))
+ return -EPERM;
+
+ base = REG_GPIO_DEBEN1 + d_bnk;
+ mutex_lock(&gpio_lock);
+ ret = gpio_twl4030_read(base);
+ if (ret >= 0) {
+ if (enable)
+ reg = ret | d_msk;
+ else
+ reg = ret & ~d_msk;
+
+ ret = gpio_twl4030_write(base, reg);
+ }
+ mutex_unlock(&gpio_lock);
+ return ret;
+}
+EXPORT_SYMBOL(twl4030_set_gpio_debounce);
+
+/*----------------------------------------------------------------------*/
+
+static int twl_request(struct gpio_chip *chip, unsigned offset)
+{
+ int status = 0;
+
+ mutex_lock(&gpio_lock);
+
+ /* Support the two LED outputs as output-only GPIOs. */
+ if (offset >= TWL4030_GPIO_MAX) {
+ u8 ledclr_mask = LEDEN_LEDAON | LEDEN_LEDAEXT
+ | LEDEN_LEDAPWM | LEDEN_PWM_LENGTHA;
+ u8 module = TWL4030_MODULE_PWMA;
+
+ offset -= TWL4030_GPIO_MAX;
+ if (offset) {
+ ledclr_mask <<= 1;
+ module = TWL4030_MODULE_PWMB;
+ }
+
+ /* initialize PWM to always-drive */
+ status = twl4030_i2c_write_u8(module, 0x7f,
+ TWL4030_PWMx_PWMxOFF);
+ if (status < 0)
+ goto done;
+ status = twl4030_i2c_write_u8(module, 0x7f,
+ TWL4030_PWMx_PWMxON);
+ if (status < 0)
+ goto done;
+
+ /* init LED to not-driven (high) */
+ module = TWL4030_MODULE_LED;
+ status = twl4030_i2c_read_u8(module, &cached_leden,
+ TWL4030_LED_LEDEN);
+ if (status < 0)
+ goto done;
+ cached_leden &= ~ledclr_mask;
+ status = twl4030_i2c_write_u8(module, cached_leden,
+ TWL4030_LED_LEDEN);
+ if (status < 0)
+ goto done;
+
+ status = 0;
+ goto done;
+ }
+
+ /* on first use, turn GPIO module "on" */
+ if (!gpio_usage_count) {
+ struct twl4030_gpio_platform_data *pdata;
+ u8 value = MASK_GPIO_CTRL_GPIO_ON;
+
+ /* optionally have the first two GPIOs switch vMMC1
+ * and vMMC2 power supplies based on card presence.
+ */
+ pdata = chip->dev->platform_data;
+ value |= pdata->mmc_cd & 0x03;
+
+ status = gpio_twl4030_write(REG_GPIO_CTRL, value);
+ }
+
+ if (!status)
+ gpio_usage_count |= (0x1 << offset);
+
+done:
+ mutex_unlock(&gpio_lock);
+ return status;
+}
+
+static void twl_free(struct gpio_chip *chip, unsigned offset)
+{
+ if (offset >= TWL4030_GPIO_MAX) {
+ twl4030_led_set_value(offset - TWL4030_GPIO_MAX, 1);
+ return;
+ }
+
+ mutex_lock(&gpio_lock);
+
+ gpio_usage_count &= ~BIT(offset);
+
+ /* on last use, switch off GPIO module */
+ if (!gpio_usage_count)
+ gpio_twl4030_write(REG_GPIO_CTRL, 0x0);
+
+ mutex_unlock(&gpio_lock);
+}
+
+static int twl_direction_in(struct gpio_chip *chip, unsigned offset)
+{
+ return (offset < TWL4030_GPIO_MAX)
+ ? twl4030_set_gpio_direction(offset, 1)
+ : -EINVAL;
+}
+
+static int twl_get(struct gpio_chip *chip, unsigned offset)
+{
+ int status = 0;
+
+ if (offset < TWL4030_GPIO_MAX)
+ status = twl4030_get_gpio_datain(offset);
+ else if (offset == TWL4030_GPIO_MAX)
+ status = cached_leden & LEDEN_LEDAON;
+ else
+ status = cached_leden & LEDEN_LEDBON;
+ return (status < 0) ? 0 : status;
+}
+
+static int twl_direction_out(struct gpio_chip *chip, unsigned offset, int value)
+{
+ if (offset < TWL4030_GPIO_MAX) {
+ twl4030_set_gpio_dataout(offset, value);
+ return twl4030_set_gpio_direction(offset, 0);
+ } else {
+ twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value);
+ return 0;
+ }
+}
+
+static void twl_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+ if (offset < TWL4030_GPIO_MAX)
+ twl4030_set_gpio_dataout(offset, value);
+ else
+ twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value);
+}
+
+static int twl_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+ return (twl4030_gpio_irq_base && (offset < TWL4030_GPIO_MAX))
+ ? (twl4030_gpio_irq_base + offset)
+ : -EINVAL;
+}
+
+static struct gpio_chip twl_gpiochip = {
+ .label = "twl4030",
+ .owner = THIS_MODULE,
+ .request = twl_request,
+ .free = twl_free,
+ .direction_input = twl_direction_in,
+ .get = twl_get,
+ .direction_output = twl_direction_out,
+ .set = twl_set,
+ .to_irq = twl_to_irq,
+ .can_sleep = 1,
+};
+
+/*----------------------------------------------------------------------*/
+
+static int __devinit gpio_twl4030_pulls(u32 ups, u32 downs)
+{
+ u8 message[6];
+ unsigned i, gpio_bit;
+
+ /* For most pins, a pulldown was enabled by default.
+ * We should have data that's specific to this board.
+ */
+ for (gpio_bit = 1, i = 1; i < 6; i++) {
+ u8 bit_mask;
+ unsigned j;
+
+ for (bit_mask = 0, j = 0; j < 8; j += 2, gpio_bit <<= 1) {
+ if (ups & gpio_bit)
+ bit_mask |= 1 << (j + 1);
+ else if (downs & gpio_bit)
+ bit_mask |= 1 << (j + 0);
+ }
+ message[i] = bit_mask;
+ }
+
+ return twl4030_i2c_write(TWL4030_MODULE_GPIO, message,
+ REG_GPIOPUPDCTR1, 5);
+}
+
+static int gpio_twl4030_remove(struct platform_device *pdev);
+
+static int __devinit gpio_twl4030_probe(struct platform_device *pdev)
+{
+ struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;
+ int ret;
+
+ /* maybe setup IRQs */
+ if (pdata->irq_base) {
+ if (is_module()) {
+ dev_err(&pdev->dev,
+ "can't dispatch IRQs from modules\n");
+ goto no_irqs;
+ }
+ ret = twl4030_sih_setup(TWL4030_MODULE_GPIO);
+ if (ret < 0)
+ return ret;
+ WARN_ON(ret != pdata->irq_base);
+ twl4030_gpio_irq_base = ret;
+ }
+
+no_irqs:
+ /*
+ * NOTE: boards may waste power if they don't set pullups
+ * and pulldowns correctly ... default for non-ULPI pins is
+ * pulldown, and some other pins may have external pullups
+ * or pulldowns. Careful!
+ */
+ ret = gpio_twl4030_pulls(pdata->pullups, pdata->pulldowns);
+ if (ret)
+ dev_dbg(&pdev->dev, "pullups %.05x %.05x --> %d\n",
+ pdata->pullups, pdata->pulldowns,
+ ret);
+
+ twl_gpiochip.base = pdata->gpio_base;
+ twl_gpiochip.ngpio = TWL4030_GPIO_MAX;
+ twl_gpiochip.dev = &pdev->dev;
+
+ /* NOTE: we assume VIBRA_CTL.VIBRA_EN, in MODULE_AUDIO_VOICE,
+ * is (still) clear if use_leds is set.
+ */
+ if (pdata->use_leds)
+ twl_gpiochip.ngpio += 2;
+
+ ret = gpiochip_add(&twl_gpiochip);
+ if (ret < 0) {
+ dev_err(&pdev->dev,
+ "could not register gpiochip, %d\n",
+ ret);
+ twl_gpiochip.ngpio = 0;
+ gpio_twl4030_remove(pdev);
+ } else if (pdata->setup) {
+ int status;
+
+ status = pdata->setup(&pdev->dev,
+ pdata->gpio_base, TWL4030_GPIO_MAX);
+ if (status)
+ dev_dbg(&pdev->dev, "setup --> %d\n", status);
+ }
+
+ return ret;
+}
+
+static int __devexit gpio_twl4030_remove(struct platform_device *pdev)
+{
+ struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;
+ int status;
+
+ if (pdata->teardown) {
+ status = pdata->teardown(&pdev->dev,
+ pdata->gpio_base, TWL4030_GPIO_MAX);
+ if (status) {
+ dev_dbg(&pdev->dev, "teardown --> %d\n", status);
+ return status;
+ }
+ }
+
+ status = gpiochip_remove(&twl_gpiochip);
+ if (status < 0)
+ return status;
+
+ if (is_module())
+ return 0;
+
+ /* REVISIT no support yet for deregistering all the IRQs */
+ WARN_ON(1);
+ return -EIO;
+}
+
+/* Note: this hardware lives inside an I2C-based multi-function device. */
+MODULE_ALIAS("platform:twl4030_gpio");
+
+static struct platform_driver gpio_twl4030_driver = {
+ .driver.name = "twl4030_gpio",
+ .driver.owner = THIS_MODULE,
+ .probe = gpio_twl4030_probe,
+ .remove = __devexit_p(gpio_twl4030_remove),
+};
+
+static int __init gpio_twl4030_init(void)
+{
+ return platform_driver_register(&gpio_twl4030_driver);
+}
+subsys_initcall(gpio_twl4030_init);
+
+static void __exit gpio_twl4030_exit(void)
+{
+ platform_driver_unregister(&gpio_twl4030_driver);
+}
+module_exit(gpio_twl4030_exit);
+
+MODULE_AUTHOR("Texas Instruments, Inc.");
+MODULE_DESCRIPTION("GPIO interface for TWL4030");
+MODULE_LICENSE("GPL");
--
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