diff options
Diffstat (limited to 'kernel/drivers/gpio/gpio-ich.c')
| -rw-r--r-- | kernel/drivers/gpio/gpio-ich.c | 546 |
1 files changed, 546 insertions, 0 deletions
diff --git a/kernel/drivers/gpio/gpio-ich.c b/kernel/drivers/gpio/gpio-ich.c new file mode 100644 index 000000000..4ba7ed502 --- /dev/null +++ b/kernel/drivers/gpio/gpio-ich.c @@ -0,0 +1,546 @@ +/* + * Intel ICH6-10, Series 5 and 6, Atom C2000 (Avoton/Rangeley) GPIO driver + * + * Copyright (C) 2010 Extreme Engineering Solutions. + * + * 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., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/pci.h> +#include <linux/gpio.h> +#include <linux/platform_device.h> +#include <linux/mfd/lpc_ich.h> + +#define DRV_NAME "gpio_ich" + +/* + * GPIO register offsets in GPIO I/O space. + * Each chunk of 32 GPIOs is manipulated via its own USE_SELx, IO_SELx, and + * LVLx registers. Logic in the read/write functions takes a register and + * an absolute bit number and determines the proper register offset and bit + * number in that register. For example, to read the value of GPIO bit 50 + * the code would access offset ichx_regs[2(=GPIO_LVL)][1(=50/32)], + * bit 18 (50%32). + */ +enum GPIO_REG { + GPIO_USE_SEL = 0, + GPIO_IO_SEL, + GPIO_LVL, + GPO_BLINK +}; + +static const u8 ichx_regs[4][3] = { + {0x00, 0x30, 0x40}, /* USE_SEL[1-3] offsets */ + {0x04, 0x34, 0x44}, /* IO_SEL[1-3] offsets */ + {0x0c, 0x38, 0x48}, /* LVL[1-3] offsets */ + {0x18, 0x18, 0x18}, /* BLINK offset */ +}; + +static const u8 ichx_reglen[3] = { + 0x30, 0x10, 0x10, +}; + +static const u8 avoton_regs[4][3] = { + {0x00, 0x80, 0x00}, + {0x04, 0x84, 0x00}, + {0x08, 0x88, 0x00}, +}; + +static const u8 avoton_reglen[3] = { + 0x10, 0x10, 0x00, +}; + +#define ICHX_WRITE(val, reg, base_res) outl(val, (reg) + (base_res)->start) +#define ICHX_READ(reg, base_res) inl((reg) + (base_res)->start) + +struct ichx_desc { + /* Max GPIO pins the chipset can have */ + uint ngpio; + + /* chipset registers */ + const u8 (*regs)[3]; + const u8 *reglen; + + /* GPO_BLINK is available on this chipset */ + bool have_blink; + + /* Whether the chipset has GPIO in GPE0_STS in the PM IO region */ + bool uses_gpe0; + + /* USE_SEL is bogus on some chipsets, eg 3100 */ + u32 use_sel_ignore[3]; + + /* Some chipsets have quirks, let these use their own request/get */ + int (*request)(struct gpio_chip *chip, unsigned offset); + int (*get)(struct gpio_chip *chip, unsigned offset); + + /* + * Some chipsets don't let reading output values on GPIO_LVL register + * this option allows driver caching written output values + */ + bool use_outlvl_cache; +}; + +static struct { + spinlock_t lock; + struct platform_device *dev; + struct gpio_chip chip; + struct resource *gpio_base; /* GPIO IO base */ + struct resource *pm_base; /* Power Mangagment IO base */ + struct ichx_desc *desc; /* Pointer to chipset-specific description */ + u32 orig_gpio_ctrl; /* Orig CTRL value, used to restore on exit */ + u8 use_gpio; /* Which GPIO groups are usable */ + int outlvl_cache[3]; /* cached output values */ +} ichx_priv; + +static int modparam_gpiobase = -1; /* dynamic */ +module_param_named(gpiobase, modparam_gpiobase, int, 0444); +MODULE_PARM_DESC(gpiobase, "The GPIO number base. -1 means dynamic, " + "which is the default."); + +static int ichx_write_bit(int reg, unsigned nr, int val, int verify) +{ + unsigned long flags; + u32 data, tmp; + int reg_nr = nr / 32; + int bit = nr & 0x1f; + int ret = 0; + + spin_lock_irqsave(&ichx_priv.lock, flags); + + if (reg == GPIO_LVL && ichx_priv.desc->use_outlvl_cache) + data = ichx_priv.outlvl_cache[reg_nr]; + else + data = ICHX_READ(ichx_priv.desc->regs[reg][reg_nr], + ichx_priv.gpio_base); + + if (val) + data |= 1 << bit; + else + data &= ~(1 << bit); + ICHX_WRITE(data, ichx_priv.desc->regs[reg][reg_nr], + ichx_priv.gpio_base); + if (reg == GPIO_LVL && ichx_priv.desc->use_outlvl_cache) + ichx_priv.outlvl_cache[reg_nr] = data; + + tmp = ICHX_READ(ichx_priv.desc->regs[reg][reg_nr], + ichx_priv.gpio_base); + if (verify && data != tmp) + ret = -EPERM; + + spin_unlock_irqrestore(&ichx_priv.lock, flags); + + return ret; +} + +static int ichx_read_bit(int reg, unsigned nr) +{ + unsigned long flags; + u32 data; + int reg_nr = nr / 32; + int bit = nr & 0x1f; + + spin_lock_irqsave(&ichx_priv.lock, flags); + + data = ICHX_READ(ichx_priv.desc->regs[reg][reg_nr], + ichx_priv.gpio_base); + + if (reg == GPIO_LVL && ichx_priv.desc->use_outlvl_cache) + data = ichx_priv.outlvl_cache[reg_nr] | data; + + spin_unlock_irqrestore(&ichx_priv.lock, flags); + + return data & (1 << bit) ? 1 : 0; +} + +static bool ichx_gpio_check_available(struct gpio_chip *gpio, unsigned nr) +{ + return !!(ichx_priv.use_gpio & (1 << (nr / 32))); +} + +static int ichx_gpio_get_direction(struct gpio_chip *gpio, unsigned nr) +{ + return ichx_read_bit(GPIO_IO_SEL, nr) ? GPIOF_DIR_IN : GPIOF_DIR_OUT; +} + +static int ichx_gpio_direction_input(struct gpio_chip *gpio, unsigned nr) +{ + /* + * Try setting pin as an input and verify it worked since many pins + * are output-only. + */ + if (ichx_write_bit(GPIO_IO_SEL, nr, 1, 1)) + return -EINVAL; + + return 0; +} + +static int ichx_gpio_direction_output(struct gpio_chip *gpio, unsigned nr, + int val) +{ + /* Disable blink hardware which is available for GPIOs from 0 to 31. */ + if (nr < 32 && ichx_priv.desc->have_blink) + ichx_write_bit(GPO_BLINK, nr, 0, 0); + + /* Set GPIO output value. */ + ichx_write_bit(GPIO_LVL, nr, val, 0); + + /* + * Try setting pin as an output and verify it worked since many pins + * are input-only. + */ + if (ichx_write_bit(GPIO_IO_SEL, nr, 0, 1)) + return -EINVAL; + + return 0; +} + +static int ichx_gpio_get(struct gpio_chip *chip, unsigned nr) +{ + return ichx_read_bit(GPIO_LVL, nr); +} + +static int ich6_gpio_get(struct gpio_chip *chip, unsigned nr) +{ + unsigned long flags; + u32 data; + + /* + * GPI 0 - 15 need to be read from the power management registers on + * a ICH6/3100 bridge. + */ + if (nr < 16) { + if (!ichx_priv.pm_base) + return -ENXIO; + + spin_lock_irqsave(&ichx_priv.lock, flags); + + /* GPI 0 - 15 are latched, write 1 to clear*/ + ICHX_WRITE(1 << (16 + nr), 0, ichx_priv.pm_base); + data = ICHX_READ(0, ichx_priv.pm_base); + + spin_unlock_irqrestore(&ichx_priv.lock, flags); + + return (data >> 16) & (1 << nr) ? 1 : 0; + } else { + return ichx_gpio_get(chip, nr); + } +} + +static int ichx_gpio_request(struct gpio_chip *chip, unsigned nr) +{ + if (!ichx_gpio_check_available(chip, nr)) + return -ENXIO; + + /* + * Note we assume the BIOS properly set a bridge's USE value. Some + * chips (eg Intel 3100) have bogus USE values though, so first see if + * the chipset's USE value can be trusted for this specific bit. + * If it can't be trusted, assume that the pin can be used as a GPIO. + */ + if (ichx_priv.desc->use_sel_ignore[nr / 32] & (1 << (nr & 0x1f))) + return 0; + + return ichx_read_bit(GPIO_USE_SEL, nr) ? 0 : -ENODEV; +} + +static int ich6_gpio_request(struct gpio_chip *chip, unsigned nr) +{ + /* + * Fixups for bits 16 and 17 are necessary on the Intel ICH6/3100 + * bridge as they are controlled by USE register bits 0 and 1. See + * "Table 704 GPIO_USE_SEL1 register" in the i3100 datasheet for + * additional info. + */ + if (nr == 16 || nr == 17) + nr -= 16; + + return ichx_gpio_request(chip, nr); +} + +static void ichx_gpio_set(struct gpio_chip *chip, unsigned nr, int val) +{ + ichx_write_bit(GPIO_LVL, nr, val, 0); +} + +static void ichx_gpiolib_setup(struct gpio_chip *chip) +{ + chip->owner = THIS_MODULE; + chip->label = DRV_NAME; + chip->dev = &ichx_priv.dev->dev; + + /* Allow chip-specific overrides of request()/get() */ + chip->request = ichx_priv.desc->request ? + ichx_priv.desc->request : ichx_gpio_request; + chip->get = ichx_priv.desc->get ? + ichx_priv.desc->get : ichx_gpio_get; + + chip->set = ichx_gpio_set; + chip->get_direction = ichx_gpio_get_direction; + chip->direction_input = ichx_gpio_direction_input; + chip->direction_output = ichx_gpio_direction_output; + chip->base = modparam_gpiobase; + chip->ngpio = ichx_priv.desc->ngpio; + chip->can_sleep = false; + chip->dbg_show = NULL; +} + +/* ICH6-based, 631xesb-based */ +static struct ichx_desc ich6_desc = { + /* Bridges using the ICH6 controller need fixups for GPIO 0 - 17 */ + .request = ich6_gpio_request, + .get = ich6_gpio_get, + + /* GPIO 0-15 are read in the GPE0_STS PM register */ + .uses_gpe0 = true, + + .ngpio = 50, + .have_blink = true, + .regs = ichx_regs, + .reglen = ichx_reglen, +}; + +/* Intel 3100 */ +static struct ichx_desc i3100_desc = { + /* + * Bits 16,17, 20 of USE_SEL and bit 16 of USE_SEL2 always read 0 on + * the Intel 3100. See "Table 712. GPIO Summary Table" of 3100 + * Datasheet for more info. + */ + .use_sel_ignore = {0x00130000, 0x00010000, 0x0}, + + /* The 3100 needs fixups for GPIO 0 - 17 */ + .request = ich6_gpio_request, + .get = ich6_gpio_get, + + /* GPIO 0-15 are read in the GPE0_STS PM register */ + .uses_gpe0 = true, + + .ngpio = 50, + .regs = ichx_regs, + .reglen = ichx_reglen, +}; + +/* ICH7 and ICH8-based */ +static struct ichx_desc ich7_desc = { + .ngpio = 50, + .have_blink = true, + .regs = ichx_regs, + .reglen = ichx_reglen, +}; + +/* ICH9-based */ +static struct ichx_desc ich9_desc = { + .ngpio = 61, + .have_blink = true, + .regs = ichx_regs, + .reglen = ichx_reglen, +}; + +/* ICH10-based - Consumer/corporate versions have different amount of GPIO */ +static struct ichx_desc ich10_cons_desc = { + .ngpio = 61, + .have_blink = true, + .regs = ichx_regs, + .reglen = ichx_reglen, +}; +static struct ichx_desc ich10_corp_desc = { + .ngpio = 72, + .have_blink = true, + .regs = ichx_regs, + .reglen = ichx_reglen, +}; + +/* Intel 5 series, 6 series, 3400 series, and C200 series */ +static struct ichx_desc intel5_desc = { + .ngpio = 76, + .regs = ichx_regs, + .reglen = ichx_reglen, +}; + +/* Avoton */ +static struct ichx_desc avoton_desc = { + /* Avoton has only 59 GPIOs, but we assume the first set of register + * (Core) has 32 instead of 31 to keep gpio-ich compliance + */ + .ngpio = 60, + .regs = avoton_regs, + .reglen = avoton_reglen, + .use_outlvl_cache = true, +}; + +static int ichx_gpio_request_regions(struct resource *res_base, + const char *name, u8 use_gpio) +{ + int i; + + if (!res_base || !res_base->start || !res_base->end) + return -ENODEV; + + for (i = 0; i < ARRAY_SIZE(ichx_priv.desc->regs[0]); i++) { + if (!(use_gpio & (1 << i))) + continue; + if (!request_region( + res_base->start + ichx_priv.desc->regs[0][i], + ichx_priv.desc->reglen[i], name)) + goto request_err; + } + return 0; + +request_err: + /* Clean up: release already requested regions, if any */ + for (i--; i >= 0; i--) { + if (!(use_gpio & (1 << i))) + continue; + release_region(res_base->start + ichx_priv.desc->regs[0][i], + ichx_priv.desc->reglen[i]); + } + return -EBUSY; +} + +static void ichx_gpio_release_regions(struct resource *res_base, u8 use_gpio) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(ichx_priv.desc->regs[0]); i++) { + if (!(use_gpio & (1 << i))) + continue; + release_region(res_base->start + ichx_priv.desc->regs[0][i], + ichx_priv.desc->reglen[i]); + } +} + +static int ichx_gpio_probe(struct platform_device *pdev) +{ + struct resource *res_base, *res_pm; + int err; + struct lpc_ich_info *ich_info = dev_get_platdata(&pdev->dev); + + if (!ich_info) + return -ENODEV; + + ichx_priv.dev = pdev; + + switch (ich_info->gpio_version) { + case ICH_I3100_GPIO: + ichx_priv.desc = &i3100_desc; + break; + case ICH_V5_GPIO: + ichx_priv.desc = &intel5_desc; + break; + case ICH_V6_GPIO: + ichx_priv.desc = &ich6_desc; + break; + case ICH_V7_GPIO: + ichx_priv.desc = &ich7_desc; + break; + case ICH_V9_GPIO: + ichx_priv.desc = &ich9_desc; + break; + case ICH_V10CORP_GPIO: + ichx_priv.desc = &ich10_corp_desc; + break; + case ICH_V10CONS_GPIO: + ichx_priv.desc = &ich10_cons_desc; + break; + case AVOTON_GPIO: + ichx_priv.desc = &avoton_desc; + break; + default: + return -ENODEV; + } + + spin_lock_init(&ichx_priv.lock); + res_base = platform_get_resource(pdev, IORESOURCE_IO, ICH_RES_GPIO); + ichx_priv.use_gpio = ich_info->use_gpio; + err = ichx_gpio_request_regions(res_base, pdev->name, + ichx_priv.use_gpio); + if (err) + return err; + + ichx_priv.gpio_base = res_base; + + /* + * If necessary, determine the I/O address of ACPI/power management + * registers which are needed to read the the GPE0 register for GPI pins + * 0 - 15 on some chipsets. + */ + if (!ichx_priv.desc->uses_gpe0) + goto init; + + res_pm = platform_get_resource(pdev, IORESOURCE_IO, ICH_RES_GPE0); + if (!res_pm) { + pr_warn("ACPI BAR is unavailable, GPI 0 - 15 unavailable\n"); + goto init; + } + + if (!request_region(res_pm->start, resource_size(res_pm), + pdev->name)) { + pr_warn("ACPI BAR is busy, GPI 0 - 15 unavailable\n"); + goto init; + } + + ichx_priv.pm_base = res_pm; + +init: + ichx_gpiolib_setup(&ichx_priv.chip); + err = gpiochip_add(&ichx_priv.chip); + if (err) { + pr_err("Failed to register GPIOs\n"); + goto add_err; + } + + pr_info("GPIO from %d to %d on %s\n", ichx_priv.chip.base, + ichx_priv.chip.base + ichx_priv.chip.ngpio - 1, DRV_NAME); + + return 0; + +add_err: + ichx_gpio_release_regions(ichx_priv.gpio_base, ichx_priv.use_gpio); + if (ichx_priv.pm_base) + release_region(ichx_priv.pm_base->start, + resource_size(ichx_priv.pm_base)); + return err; +} + +static int ichx_gpio_remove(struct platform_device *pdev) +{ + gpiochip_remove(&ichx_priv.chip); + + ichx_gpio_release_regions(ichx_priv.gpio_base, ichx_priv.use_gpio); + if (ichx_priv.pm_base) + release_region(ichx_priv.pm_base->start, + resource_size(ichx_priv.pm_base)); + + return 0; +} + +static struct platform_driver ichx_gpio_driver = { + .driver = { + .name = DRV_NAME, + }, + .probe = ichx_gpio_probe, + .remove = ichx_gpio_remove, +}; + +module_platform_driver(ichx_gpio_driver); + +MODULE_AUTHOR("Peter Tyser <ptyser@xes-inc.com>"); +MODULE_DESCRIPTION("GPIO interface for Intel ICH series"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:"DRV_NAME); |