diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/gpio/gpio-aspeed-sgpio.c | 573 |
1 files changed, 573 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-aspeed-sgpio.c b/drivers/gpio/gpio-aspeed-sgpio.c new file mode 100644 index 000000000..64e54f8c3 --- /dev/null +++ b/drivers/gpio/gpio-aspeed-sgpio.c @@ -0,0 +1,573 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright 2019 American Megatrends International LLC. + * + * Author: Karthikeyan Mani <karthikeyanm@amiindia.co.in> + */ + +#include <linux/bitfield.h> +#include <linux/clk.h> +#include <linux/gpio/driver.h> +#include <linux/hashtable.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/spinlock.h> +#include <linux/string.h> + +/* + * MAX_NR_HW_GPIO represents the number of actual hardware-supported GPIOs (ie, + * slots within the clocked serial GPIO data). Since each HW GPIO is both an + * input and an output, we provide MAX_NR_HW_GPIO * 2 lines on our gpiochip + * device. + * + * We use SGPIO_OUTPUT_OFFSET to define the split between the inputs and + * outputs; the inputs start at line 0, the outputs start at OUTPUT_OFFSET. + */ +#define MAX_NR_HW_SGPIO 80 +#define SGPIO_OUTPUT_OFFSET MAX_NR_HW_SGPIO + +#define ASPEED_SGPIO_CTRL 0x54 + +#define ASPEED_SGPIO_PINS_MASK GENMASK(9, 6) +#define ASPEED_SGPIO_CLK_DIV_MASK GENMASK(31, 16) +#define ASPEED_SGPIO_ENABLE BIT(0) + +struct aspeed_sgpio { + struct gpio_chip chip; + struct clk *pclk; + spinlock_t lock; + void __iomem *base; + int irq; + int n_sgpio; +}; + +struct aspeed_sgpio_bank { + uint16_t val_regs; + uint16_t rdata_reg; + uint16_t irq_regs; + const char names[4][3]; +}; + +/* + * Note: The "value" register returns the input value when the GPIO is + * configured as an input. + * + * The "rdata" register returns the output value when the GPIO is + * configured as an output. + */ +static const struct aspeed_sgpio_bank aspeed_sgpio_banks[] = { + { + .val_regs = 0x0000, + .rdata_reg = 0x0070, + .irq_regs = 0x0004, + .names = { "A", "B", "C", "D" }, + }, + { + .val_regs = 0x001C, + .rdata_reg = 0x0074, + .irq_regs = 0x0020, + .names = { "E", "F", "G", "H" }, + }, + { + .val_regs = 0x0038, + .rdata_reg = 0x0078, + .irq_regs = 0x003C, + .names = { "I", "J" }, + }, +}; + +enum aspeed_sgpio_reg { + reg_val, + reg_rdata, + reg_irq_enable, + reg_irq_type0, + reg_irq_type1, + reg_irq_type2, + reg_irq_status, +}; + +#define GPIO_VAL_VALUE 0x00 +#define GPIO_IRQ_ENABLE 0x00 +#define GPIO_IRQ_TYPE0 0x04 +#define GPIO_IRQ_TYPE1 0x08 +#define GPIO_IRQ_TYPE2 0x0C +#define GPIO_IRQ_STATUS 0x10 + +static void __iomem *bank_reg(struct aspeed_sgpio *gpio, + const struct aspeed_sgpio_bank *bank, + const enum aspeed_sgpio_reg reg) +{ + switch (reg) { + case reg_val: + return gpio->base + bank->val_regs + GPIO_VAL_VALUE; + case reg_rdata: + return gpio->base + bank->rdata_reg; + case reg_irq_enable: + return gpio->base + bank->irq_regs + GPIO_IRQ_ENABLE; + case reg_irq_type0: + return gpio->base + bank->irq_regs + GPIO_IRQ_TYPE0; + case reg_irq_type1: + return gpio->base + bank->irq_regs + GPIO_IRQ_TYPE1; + case reg_irq_type2: + return gpio->base + bank->irq_regs + GPIO_IRQ_TYPE2; + case reg_irq_status: + return gpio->base + bank->irq_regs + GPIO_IRQ_STATUS; + default: + /* acturally if code runs to here, it's an error case */ + BUG(); + } +} + +#define GPIO_BANK(x) ((x % SGPIO_OUTPUT_OFFSET) >> 5) +#define GPIO_OFFSET(x) ((x % SGPIO_OUTPUT_OFFSET) & 0x1f) +#define GPIO_BIT(x) BIT(GPIO_OFFSET(x)) + +static const struct aspeed_sgpio_bank *to_bank(unsigned int offset) +{ + unsigned int bank; + + bank = GPIO_BANK(offset); + + WARN_ON(bank >= ARRAY_SIZE(aspeed_sgpio_banks)); + return &aspeed_sgpio_banks[bank]; +} + +static int aspeed_sgpio_init_valid_mask(struct gpio_chip *gc, + unsigned long *valid_mask, unsigned int ngpios) +{ + struct aspeed_sgpio *sgpio = gpiochip_get_data(gc); + int n = sgpio->n_sgpio; + int c = SGPIO_OUTPUT_OFFSET - n; + + WARN_ON(ngpios < MAX_NR_HW_SGPIO * 2); + + /* input GPIOs in the lower range */ + bitmap_set(valid_mask, 0, n); + bitmap_clear(valid_mask, n, c); + + /* output GPIOS above SGPIO_OUTPUT_OFFSET */ + bitmap_set(valid_mask, SGPIO_OUTPUT_OFFSET, n); + bitmap_clear(valid_mask, SGPIO_OUTPUT_OFFSET + n, c); + + return 0; +} + +static void aspeed_sgpio_irq_init_valid_mask(struct gpio_chip *gc, + unsigned long *valid_mask, unsigned int ngpios) +{ + struct aspeed_sgpio *sgpio = gpiochip_get_data(gc); + int n = sgpio->n_sgpio; + + WARN_ON(ngpios < MAX_NR_HW_SGPIO * 2); + + /* input GPIOs in the lower range */ + bitmap_set(valid_mask, 0, n); + bitmap_clear(valid_mask, n, ngpios - n); +} + +static bool aspeed_sgpio_is_input(unsigned int offset) +{ + return offset < SGPIO_OUTPUT_OFFSET; +} + +static int aspeed_sgpio_get(struct gpio_chip *gc, unsigned int offset) +{ + struct aspeed_sgpio *gpio = gpiochip_get_data(gc); + const struct aspeed_sgpio_bank *bank = to_bank(offset); + unsigned long flags; + enum aspeed_sgpio_reg reg; + int rc = 0; + + spin_lock_irqsave(&gpio->lock, flags); + + reg = aspeed_sgpio_is_input(offset) ? reg_val : reg_rdata; + rc = !!(ioread32(bank_reg(gpio, bank, reg)) & GPIO_BIT(offset)); + + spin_unlock_irqrestore(&gpio->lock, flags); + + return rc; +} + +static int sgpio_set_value(struct gpio_chip *gc, unsigned int offset, int val) +{ + struct aspeed_sgpio *gpio = gpiochip_get_data(gc); + const struct aspeed_sgpio_bank *bank = to_bank(offset); + void __iomem *addr_r, *addr_w; + u32 reg = 0; + + if (aspeed_sgpio_is_input(offset)) + return -EINVAL; + + /* Since this is an output, read the cached value from rdata, then + * update val. */ + addr_r = bank_reg(gpio, bank, reg_rdata); + addr_w = bank_reg(gpio, bank, reg_val); + + reg = ioread32(addr_r); + + if (val) + reg |= GPIO_BIT(offset); + else + reg &= ~GPIO_BIT(offset); + + iowrite32(reg, addr_w); + + return 0; +} + +static void aspeed_sgpio_set(struct gpio_chip *gc, unsigned int offset, int val) +{ + struct aspeed_sgpio *gpio = gpiochip_get_data(gc); + unsigned long flags; + + spin_lock_irqsave(&gpio->lock, flags); + + sgpio_set_value(gc, offset, val); + + spin_unlock_irqrestore(&gpio->lock, flags); +} + +static int aspeed_sgpio_dir_in(struct gpio_chip *gc, unsigned int offset) +{ + return aspeed_sgpio_is_input(offset) ? 0 : -EINVAL; +} + +static int aspeed_sgpio_dir_out(struct gpio_chip *gc, unsigned int offset, int val) +{ + struct aspeed_sgpio *gpio = gpiochip_get_data(gc); + unsigned long flags; + int rc; + + /* No special action is required for setting the direction; we'll + * error-out in sgpio_set_value if this isn't an output GPIO */ + + spin_lock_irqsave(&gpio->lock, flags); + rc = sgpio_set_value(gc, offset, val); + spin_unlock_irqrestore(&gpio->lock, flags); + + return rc; +} + +static int aspeed_sgpio_get_direction(struct gpio_chip *gc, unsigned int offset) +{ + return !!aspeed_sgpio_is_input(offset); +} + +static void irqd_to_aspeed_sgpio_data(struct irq_data *d, + struct aspeed_sgpio **gpio, + const struct aspeed_sgpio_bank **bank, + u32 *bit, int *offset) +{ + struct aspeed_sgpio *internal; + + *offset = irqd_to_hwirq(d); + internal = irq_data_get_irq_chip_data(d); + WARN_ON(!internal); + + *gpio = internal; + *bank = to_bank(*offset); + *bit = GPIO_BIT(*offset); +} + +static void aspeed_sgpio_irq_ack(struct irq_data *d) +{ + const struct aspeed_sgpio_bank *bank; + struct aspeed_sgpio *gpio; + unsigned long flags; + void __iomem *status_addr; + int offset; + u32 bit; + + irqd_to_aspeed_sgpio_data(d, &gpio, &bank, &bit, &offset); + + status_addr = bank_reg(gpio, bank, reg_irq_status); + + spin_lock_irqsave(&gpio->lock, flags); + + iowrite32(bit, status_addr); + + spin_unlock_irqrestore(&gpio->lock, flags); +} + +static void aspeed_sgpio_irq_set_mask(struct irq_data *d, bool set) +{ + const struct aspeed_sgpio_bank *bank; + struct aspeed_sgpio *gpio; + unsigned long flags; + u32 reg, bit; + void __iomem *addr; + int offset; + + irqd_to_aspeed_sgpio_data(d, &gpio, &bank, &bit, &offset); + addr = bank_reg(gpio, bank, reg_irq_enable); + + spin_lock_irqsave(&gpio->lock, flags); + + reg = ioread32(addr); + if (set) + reg |= bit; + else + reg &= ~bit; + + iowrite32(reg, addr); + + spin_unlock_irqrestore(&gpio->lock, flags); +} + +static void aspeed_sgpio_irq_mask(struct irq_data *d) +{ + aspeed_sgpio_irq_set_mask(d, false); +} + +static void aspeed_sgpio_irq_unmask(struct irq_data *d) +{ + aspeed_sgpio_irq_set_mask(d, true); +} + +static int aspeed_sgpio_set_type(struct irq_data *d, unsigned int type) +{ + u32 type0 = 0; + u32 type1 = 0; + u32 type2 = 0; + u32 bit, reg; + const struct aspeed_sgpio_bank *bank; + irq_flow_handler_t handler; + struct aspeed_sgpio *gpio; + unsigned long flags; + void __iomem *addr; + int offset; + + irqd_to_aspeed_sgpio_data(d, &gpio, &bank, &bit, &offset); + + switch (type & IRQ_TYPE_SENSE_MASK) { + case IRQ_TYPE_EDGE_BOTH: + type2 |= bit; + fallthrough; + case IRQ_TYPE_EDGE_RISING: + type0 |= bit; + fallthrough; + case IRQ_TYPE_EDGE_FALLING: + handler = handle_edge_irq; + break; + case IRQ_TYPE_LEVEL_HIGH: + type0 |= bit; + fallthrough; + case IRQ_TYPE_LEVEL_LOW: + type1 |= bit; + handler = handle_level_irq; + break; + default: + return -EINVAL; + } + + spin_lock_irqsave(&gpio->lock, flags); + + addr = bank_reg(gpio, bank, reg_irq_type0); + reg = ioread32(addr); + reg = (reg & ~bit) | type0; + iowrite32(reg, addr); + + addr = bank_reg(gpio, bank, reg_irq_type1); + reg = ioread32(addr); + reg = (reg & ~bit) | type1; + iowrite32(reg, addr); + + addr = bank_reg(gpio, bank, reg_irq_type2); + reg = ioread32(addr); + reg = (reg & ~bit) | type2; + iowrite32(reg, addr); + + spin_unlock_irqrestore(&gpio->lock, flags); + + irq_set_handler_locked(d, handler); + + return 0; +} + +static void aspeed_sgpio_irq_handler(struct irq_desc *desc) +{ + struct gpio_chip *gc = irq_desc_get_handler_data(desc); + struct irq_chip *ic = irq_desc_get_chip(desc); + struct aspeed_sgpio *data = gpiochip_get_data(gc); + unsigned int i, p, girq; + unsigned long reg; + + chained_irq_enter(ic, desc); + + for (i = 0; i < ARRAY_SIZE(aspeed_sgpio_banks); i++) { + const struct aspeed_sgpio_bank *bank = &aspeed_sgpio_banks[i]; + + reg = ioread32(bank_reg(data, bank, reg_irq_status)); + + for_each_set_bit(p, ®, 32) { + girq = irq_find_mapping(gc->irq.domain, i * 32 + p); + generic_handle_irq(girq); + } + + } + + chained_irq_exit(ic, desc); +} + +static struct irq_chip aspeed_sgpio_irqchip = { + .name = "aspeed-sgpio", + .irq_ack = aspeed_sgpio_irq_ack, + .irq_mask = aspeed_sgpio_irq_mask, + .irq_unmask = aspeed_sgpio_irq_unmask, + .irq_set_type = aspeed_sgpio_set_type, +}; + +static int aspeed_sgpio_setup_irqs(struct aspeed_sgpio *gpio, + struct platform_device *pdev) +{ + int rc, i; + const struct aspeed_sgpio_bank *bank; + struct gpio_irq_chip *irq; + + rc = platform_get_irq(pdev, 0); + if (rc < 0) + return rc; + + gpio->irq = rc; + + /* Disable IRQ and clear Interrupt status registers for all SGPIO Pins. */ + for (i = 0; i < ARRAY_SIZE(aspeed_sgpio_banks); i++) { + bank = &aspeed_sgpio_banks[i]; + /* disable irq enable bits */ + iowrite32(0x00000000, bank_reg(gpio, bank, reg_irq_enable)); + /* clear status bits */ + iowrite32(0xffffffff, bank_reg(gpio, bank, reg_irq_status)); + } + + irq = &gpio->chip.irq; + irq->chip = &aspeed_sgpio_irqchip; + irq->init_valid_mask = aspeed_sgpio_irq_init_valid_mask; + irq->handler = handle_bad_irq; + irq->default_type = IRQ_TYPE_NONE; + irq->parent_handler = aspeed_sgpio_irq_handler; + irq->parent_handler_data = gpio; + irq->parents = &gpio->irq; + irq->num_parents = 1; + + /* Apply default IRQ settings */ + for (i = 0; i < ARRAY_SIZE(aspeed_sgpio_banks); i++) { + bank = &aspeed_sgpio_banks[i]; + /* set falling or level-low irq */ + iowrite32(0x00000000, bank_reg(gpio, bank, reg_irq_type0)); + /* trigger type is edge */ + iowrite32(0x00000000, bank_reg(gpio, bank, reg_irq_type1)); + /* single edge trigger */ + iowrite32(0x00000000, bank_reg(gpio, bank, reg_irq_type2)); + } + + return 0; +} + +static const struct of_device_id aspeed_sgpio_of_table[] = { + { .compatible = "aspeed,ast2400-sgpio" }, + { .compatible = "aspeed,ast2500-sgpio" }, + {} +}; + +MODULE_DEVICE_TABLE(of, aspeed_sgpio_of_table); + +static int __init aspeed_sgpio_probe(struct platform_device *pdev) +{ + struct aspeed_sgpio *gpio; + u32 nr_gpios, sgpio_freq, sgpio_clk_div; + int rc; + unsigned long apb_freq; + + gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL); + if (!gpio) + return -ENOMEM; + + gpio->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(gpio->base)) + return PTR_ERR(gpio->base); + + rc = of_property_read_u32(pdev->dev.of_node, "ngpios", &nr_gpios); + if (rc < 0) { + dev_err(&pdev->dev, "Could not read ngpios property\n"); + return -EINVAL; + } else if (nr_gpios > MAX_NR_HW_SGPIO) { + dev_err(&pdev->dev, "Number of GPIOs exceeds the maximum of %d: %d\n", + MAX_NR_HW_SGPIO, nr_gpios); + return -EINVAL; + } + gpio->n_sgpio = nr_gpios; + + rc = of_property_read_u32(pdev->dev.of_node, "bus-frequency", &sgpio_freq); + if (rc < 0) { + dev_err(&pdev->dev, "Could not read bus-frequency property\n"); + return -EINVAL; + } + + gpio->pclk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(gpio->pclk)) { + dev_err(&pdev->dev, "devm_clk_get failed\n"); + return PTR_ERR(gpio->pclk); + } + + apb_freq = clk_get_rate(gpio->pclk); + + /* + * From the datasheet, + * SGPIO period = 1/PCLK * 2 * (GPIO254[31:16] + 1) + * period = 2 * (GPIO254[31:16] + 1) / PCLK + * frequency = 1 / (2 * (GPIO254[31:16] + 1) / PCLK) + * frequency = PCLK / (2 * (GPIO254[31:16] + 1)) + * frequency * 2 * (GPIO254[31:16] + 1) = PCLK + * GPIO254[31:16] = PCLK / (frequency * 2) - 1 + */ + if (sgpio_freq == 0) + return -EINVAL; + + sgpio_clk_div = (apb_freq / (sgpio_freq * 2)) - 1; + + if (sgpio_clk_div > (1 << 16) - 1) + return -EINVAL; + + iowrite32(FIELD_PREP(ASPEED_SGPIO_CLK_DIV_MASK, sgpio_clk_div) | + FIELD_PREP(ASPEED_SGPIO_PINS_MASK, (nr_gpios / 8)) | + ASPEED_SGPIO_ENABLE, + gpio->base + ASPEED_SGPIO_CTRL); + + spin_lock_init(&gpio->lock); + + gpio->chip.parent = &pdev->dev; + gpio->chip.ngpio = MAX_NR_HW_SGPIO * 2; + gpio->chip.init_valid_mask = aspeed_sgpio_init_valid_mask; + gpio->chip.direction_input = aspeed_sgpio_dir_in; + gpio->chip.direction_output = aspeed_sgpio_dir_out; + gpio->chip.get_direction = aspeed_sgpio_get_direction; + gpio->chip.request = NULL; + gpio->chip.free = NULL; + gpio->chip.get = aspeed_sgpio_get; + gpio->chip.set = aspeed_sgpio_set; + gpio->chip.set_config = NULL; + gpio->chip.label = dev_name(&pdev->dev); + gpio->chip.base = -1; + + aspeed_sgpio_setup_irqs(gpio, pdev); + + rc = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio); + if (rc < 0) + return rc; + + return 0; +} + +static struct platform_driver aspeed_sgpio_driver = { + .driver = { + .name = KBUILD_MODNAME, + .of_match_table = aspeed_sgpio_of_table, + }, +}; + +module_platform_driver_probe(aspeed_sgpio_driver, aspeed_sgpio_probe); +MODULE_DESCRIPTION("Aspeed Serial GPIO Driver"); +MODULE_LICENSE("GPL"); |