// 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);