diff options
Diffstat (limited to 'drivers/gpio/gpio-cs5535.c')
| -rw-r--r-- | drivers/gpio/gpio-cs5535.c | 364 |
1 files changed, 364 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-cs5535.c b/drivers/gpio/gpio-cs5535.c new file mode 100644 index 000000000..6da3a2476 --- /dev/null +++ b/drivers/gpio/gpio-cs5535.c @@ -0,0 +1,364 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AMD CS5535/CS5536 GPIO driver + * Copyright (C) 2006 Advanced Micro Devices, Inc. + * Copyright (C) 2007-2009 Andres Salomon <dilinger@collabora.co.uk> + */ + +#include <linux/kernel.h> +#include <linux/spinlock.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/gpio/driver.h> +#include <linux/io.h> +#include <linux/cs5535.h> +#include <asm/msr.h> + +#define DRV_NAME "cs5535-gpio" + +/* + * Some GPIO pins + * 31-29,23 : reserved (always mask out) + * 28 : Power Button + * 26 : PME# + * 22-16 : LPC + * 14,15 : SMBus + * 9,8 : UART1 + * 7 : PCI INTB + * 3,4 : UART2/DDC + * 2 : IDE_IRQ0 + * 1 : AC_BEEP + * 0 : PCI INTA + * + * If a mask was not specified, allow all except + * reserved and Power Button + */ +#define GPIO_DEFAULT_MASK 0x0F7FFFFF + +static ulong mask = GPIO_DEFAULT_MASK; +module_param_named(mask, mask, ulong, 0444); +MODULE_PARM_DESC(mask, "GPIO channel mask."); + +/* + * FIXME: convert this singleton driver to use the state container + * design pattern, see Documentation/driver-api/driver-model/design-patterns.rst + */ +static struct cs5535_gpio_chip { + struct gpio_chip chip; + resource_size_t base; + + struct platform_device *pdev; + spinlock_t lock; +} cs5535_gpio_chip; + +/* + * The CS5535/CS5536 GPIOs support a number of extra features not defined + * by the gpio_chip API, so these are exported. For a full list of the + * registers, see include/linux/cs5535.h. + */ + +static void errata_outl(struct cs5535_gpio_chip *chip, u32 val, + unsigned int reg) +{ + unsigned long addr = chip->base + 0x80 + reg; + + /* + * According to the CS5536 errata (#36), after suspend + * a write to the high bank GPIO register will clear all + * non-selected bits; the recommended workaround is a + * read-modify-write operation. + * + * Don't apply this errata to the edge status GPIOs, as writing + * to their lower bits will clear them. + */ + if (reg != GPIO_POSITIVE_EDGE_STS && reg != GPIO_NEGATIVE_EDGE_STS) { + if (val & 0xffff) + val |= (inl(addr) & 0xffff); /* ignore the high bits */ + else + val |= (inl(addr) ^ (val >> 16)); + } + outl(val, addr); +} + +static void __cs5535_gpio_set(struct cs5535_gpio_chip *chip, unsigned offset, + unsigned int reg) +{ + if (offset < 16) + /* low bank register */ + outl(1 << offset, chip->base + reg); + else + /* high bank register */ + errata_outl(chip, 1 << (offset - 16), reg); +} + +void cs5535_gpio_set(unsigned offset, unsigned int reg) +{ + struct cs5535_gpio_chip *chip = &cs5535_gpio_chip; + unsigned long flags; + + spin_lock_irqsave(&chip->lock, flags); + __cs5535_gpio_set(chip, offset, reg); + spin_unlock_irqrestore(&chip->lock, flags); +} +EXPORT_SYMBOL_GPL(cs5535_gpio_set); + +static void __cs5535_gpio_clear(struct cs5535_gpio_chip *chip, unsigned offset, + unsigned int reg) +{ + if (offset < 16) + /* low bank register */ + outl(1 << (offset + 16), chip->base + reg); + else + /* high bank register */ + errata_outl(chip, 1 << offset, reg); +} + +void cs5535_gpio_clear(unsigned offset, unsigned int reg) +{ + struct cs5535_gpio_chip *chip = &cs5535_gpio_chip; + unsigned long flags; + + spin_lock_irqsave(&chip->lock, flags); + __cs5535_gpio_clear(chip, offset, reg); + spin_unlock_irqrestore(&chip->lock, flags); +} +EXPORT_SYMBOL_GPL(cs5535_gpio_clear); + +int cs5535_gpio_isset(unsigned offset, unsigned int reg) +{ + struct cs5535_gpio_chip *chip = &cs5535_gpio_chip; + unsigned long flags; + long val; + + spin_lock_irqsave(&chip->lock, flags); + if (offset < 16) + /* low bank register */ + val = inl(chip->base + reg); + else { + /* high bank register */ + val = inl(chip->base + 0x80 + reg); + offset -= 16; + } + spin_unlock_irqrestore(&chip->lock, flags); + + return (val & (1 << offset)) ? 1 : 0; +} +EXPORT_SYMBOL_GPL(cs5535_gpio_isset); + +int cs5535_gpio_set_irq(unsigned group, unsigned irq) +{ + uint32_t lo, hi; + + if (group > 7 || irq > 15) + return -EINVAL; + + rdmsr(MSR_PIC_ZSEL_HIGH, lo, hi); + + lo &= ~(0xF << (group * 4)); + lo |= (irq & 0xF) << (group * 4); + + wrmsr(MSR_PIC_ZSEL_HIGH, lo, hi); + return 0; +} +EXPORT_SYMBOL_GPL(cs5535_gpio_set_irq); + +void cs5535_gpio_setup_event(unsigned offset, int pair, int pme) +{ + struct cs5535_gpio_chip *chip = &cs5535_gpio_chip; + uint32_t shift = (offset % 8) * 4; + unsigned long flags; + uint32_t val; + + if (offset >= 24) + offset = GPIO_MAP_W; + else if (offset >= 16) + offset = GPIO_MAP_Z; + else if (offset >= 8) + offset = GPIO_MAP_Y; + else + offset = GPIO_MAP_X; + + spin_lock_irqsave(&chip->lock, flags); + val = inl(chip->base + offset); + + /* Clear whatever was there before */ + val &= ~(0xF << shift); + + /* Set the new value */ + val |= ((pair & 7) << shift); + + /* Set the PME bit if this is a PME event */ + if (pme) + val |= (1 << (shift + 3)); + + outl(val, chip->base + offset); + spin_unlock_irqrestore(&chip->lock, flags); +} +EXPORT_SYMBOL_GPL(cs5535_gpio_setup_event); + +/* + * Generic gpio_chip API support. + */ + +static int chip_gpio_request(struct gpio_chip *c, unsigned offset) +{ + struct cs5535_gpio_chip *chip = gpiochip_get_data(c); + unsigned long flags; + + spin_lock_irqsave(&chip->lock, flags); + + /* check if this pin is available */ + if ((mask & (1 << offset)) == 0) { + dev_info(&chip->pdev->dev, + "pin %u is not available (check mask)\n", offset); + spin_unlock_irqrestore(&chip->lock, flags); + return -EINVAL; + } + + /* disable output aux 1 & 2 on this pin */ + __cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_AUX1); + __cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_AUX2); + + /* disable input aux 1 on this pin */ + __cs5535_gpio_clear(chip, offset, GPIO_INPUT_AUX1); + + spin_unlock_irqrestore(&chip->lock, flags); + + return 0; +} + +static int chip_gpio_get(struct gpio_chip *chip, unsigned offset) +{ + return cs5535_gpio_isset(offset, GPIO_READ_BACK); +} + +static void chip_gpio_set(struct gpio_chip *chip, unsigned offset, int val) +{ + if (val) + cs5535_gpio_set(offset, GPIO_OUTPUT_VAL); + else + cs5535_gpio_clear(offset, GPIO_OUTPUT_VAL); +} + +static int chip_direction_input(struct gpio_chip *c, unsigned offset) +{ + struct cs5535_gpio_chip *chip = gpiochip_get_data(c); + unsigned long flags; + + spin_lock_irqsave(&chip->lock, flags); + __cs5535_gpio_set(chip, offset, GPIO_INPUT_ENABLE); + __cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_ENABLE); + spin_unlock_irqrestore(&chip->lock, flags); + + return 0; +} + +static int chip_direction_output(struct gpio_chip *c, unsigned offset, int val) +{ + struct cs5535_gpio_chip *chip = gpiochip_get_data(c); + unsigned long flags; + + spin_lock_irqsave(&chip->lock, flags); + + __cs5535_gpio_set(chip, offset, GPIO_INPUT_ENABLE); + __cs5535_gpio_set(chip, offset, GPIO_OUTPUT_ENABLE); + if (val) + __cs5535_gpio_set(chip, offset, GPIO_OUTPUT_VAL); + else + __cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_VAL); + + spin_unlock_irqrestore(&chip->lock, flags); + + return 0; +} + +static const char * const cs5535_gpio_names[] = { + "GPIO0", "GPIO1", "GPIO2", "GPIO3", + "GPIO4", "GPIO5", "GPIO6", "GPIO7", + "GPIO8", "GPIO9", "GPIO10", "GPIO11", + "GPIO12", "GPIO13", "GPIO14", "GPIO15", + "GPIO16", "GPIO17", "GPIO18", "GPIO19", + "GPIO20", "GPIO21", "GPIO22", NULL, + "GPIO24", "GPIO25", "GPIO26", "GPIO27", + "GPIO28", NULL, NULL, NULL, +}; + +static struct cs5535_gpio_chip cs5535_gpio_chip = { + .chip = { + .owner = THIS_MODULE, + .label = DRV_NAME, + + .base = 0, + .ngpio = 32, + .names = cs5535_gpio_names, + .request = chip_gpio_request, + + .get = chip_gpio_get, + .set = chip_gpio_set, + + .direction_input = chip_direction_input, + .direction_output = chip_direction_output, + }, +}; + +static int cs5535_gpio_probe(struct platform_device *pdev) +{ + struct resource *res; + int err = -EIO; + ulong mask_orig = mask; + + /* There are two ways to get the GPIO base address; one is by + * fetching it from MSR_LBAR_GPIO, the other is by reading the + * PCI BAR info. The latter method is easier (especially across + * different architectures), so we'll stick with that for now. If + * it turns out to be unreliable in the face of crappy BIOSes, we + * can always go back to using MSRs.. */ + + res = platform_get_resource(pdev, IORESOURCE_IO, 0); + if (!res) { + dev_err(&pdev->dev, "can't fetch device resource info\n"); + return err; + } + + if (!devm_request_region(&pdev->dev, res->start, resource_size(res), + pdev->name)) { + dev_err(&pdev->dev, "can't request region\n"); + return err; + } + + /* set up the driver-specific struct */ + cs5535_gpio_chip.base = res->start; + cs5535_gpio_chip.pdev = pdev; + spin_lock_init(&cs5535_gpio_chip.lock); + + dev_info(&pdev->dev, "reserved resource region %pR\n", res); + + /* mask out reserved pins */ + mask &= 0x1F7FFFFF; + + /* do not allow pin 28, Power Button, as there's special handling + * in the PMC needed. (note 12, p. 48) */ + mask &= ~(1 << 28); + + if (mask_orig != mask) + dev_info(&pdev->dev, "mask changed from 0x%08lX to 0x%08lX\n", + mask_orig, mask); + + /* finally, register with the generic GPIO API */ + return devm_gpiochip_add_data(&pdev->dev, &cs5535_gpio_chip.chip, + &cs5535_gpio_chip); +} + +static struct platform_driver cs5535_gpio_driver = { + .driver = { + .name = DRV_NAME, + }, + .probe = cs5535_gpio_probe, +}; + +module_platform_driver(cs5535_gpio_driver); + +MODULE_AUTHOR("Andres Salomon <dilinger@queued.net>"); +MODULE_DESCRIPTION("AMD CS5535/CS5536 GPIO driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:" DRV_NAME); |