diff options
Diffstat (limited to 'drivers/gpio/gpio-aspeed.c')
-rw-r--r-- | drivers/gpio/gpio-aspeed.c | 1251 |
1 files changed, 1251 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-aspeed.c b/drivers/gpio/gpio-aspeed.c new file mode 100644 index 000000000..42d3e1cf7 --- /dev/null +++ b/drivers/gpio/gpio-aspeed.c @@ -0,0 +1,1251 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright 2015 IBM Corp. + * + * Joel Stanley <joel@jms.id.au> + */ + +#include <asm/div64.h> +#include <linux/clk.h> +#include <linux/gpio/driver.h> +#include <linux/gpio/aspeed.h> +#include <linux/hashtable.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/pinctrl/consumer.h> +#include <linux/platform_device.h> +#include <linux/spinlock.h> +#include <linux/string.h> + +/* + * These two headers aren't meant to be used by GPIO drivers. We need + * them in order to access gpio_chip_hwgpio() which we need to implement + * the aspeed specific API which allows the coprocessor to request + * access to some GPIOs and to arbitrate between coprocessor and ARM. + */ +#include <linux/gpio/consumer.h> +#include "gpiolib.h" + +struct aspeed_bank_props { + unsigned int bank; + u32 input; + u32 output; +}; + +struct aspeed_gpio_config { + unsigned int nr_gpios; + const struct aspeed_bank_props *props; +}; + +/* + * @offset_timer: Maps an offset to an @timer_users index, or zero if disabled + * @timer_users: Tracks the number of users for each timer + * + * The @timer_users has four elements but the first element is unused. This is + * to simplify accounting and indexing, as a zero value in @offset_timer + * represents disabled debouncing for the GPIO. Any other value for an element + * of @offset_timer is used as an index into @timer_users. This behaviour of + * the zero value aligns with the behaviour of zero built from the timer + * configuration registers (i.e. debouncing is disabled). + */ +struct aspeed_gpio { + struct gpio_chip chip; + struct irq_chip irqc; + raw_spinlock_t lock; + void __iomem *base; + int irq; + const struct aspeed_gpio_config *config; + + u8 *offset_timer; + unsigned int timer_users[4]; + struct clk *clk; + + u32 *dcache; + u8 *cf_copro_bankmap; +}; + +struct aspeed_gpio_bank { + uint16_t val_regs; /* +0: Rd: read input value, Wr: set write latch + * +4: Rd/Wr: Direction (0=in, 1=out) + */ + uint16_t rdata_reg; /* Rd: read write latch, Wr: <none> */ + uint16_t irq_regs; + uint16_t debounce_regs; + uint16_t tolerance_regs; + uint16_t cmdsrc_regs; + const char names[4][3]; +}; + +/* + * Note: The "value" register returns the input value sampled on the + * line even when the GPIO is configured as an output. Since + * that input goes through synchronizers, writing, then reading + * back may not return the written value right away. + * + * The "rdata" register returns the content of the write latch + * and thus can be used to read back what was last written + * reliably. + */ + +static const int debounce_timers[4] = { 0x00, 0x50, 0x54, 0x58 }; + +static const struct aspeed_gpio_copro_ops *copro_ops; +static void *copro_data; + +static const struct aspeed_gpio_bank aspeed_gpio_banks[] = { + { + .val_regs = 0x0000, + .rdata_reg = 0x00c0, + .irq_regs = 0x0008, + .debounce_regs = 0x0040, + .tolerance_regs = 0x001c, + .cmdsrc_regs = 0x0060, + .names = { "A", "B", "C", "D" }, + }, + { + .val_regs = 0x0020, + .rdata_reg = 0x00c4, + .irq_regs = 0x0028, + .debounce_regs = 0x0048, + .tolerance_regs = 0x003c, + .cmdsrc_regs = 0x0068, + .names = { "E", "F", "G", "H" }, + }, + { + .val_regs = 0x0070, + .rdata_reg = 0x00c8, + .irq_regs = 0x0098, + .debounce_regs = 0x00b0, + .tolerance_regs = 0x00ac, + .cmdsrc_regs = 0x0090, + .names = { "I", "J", "K", "L" }, + }, + { + .val_regs = 0x0078, + .rdata_reg = 0x00cc, + .irq_regs = 0x00e8, + .debounce_regs = 0x0100, + .tolerance_regs = 0x00fc, + .cmdsrc_regs = 0x00e0, + .names = { "M", "N", "O", "P" }, + }, + { + .val_regs = 0x0080, + .rdata_reg = 0x00d0, + .irq_regs = 0x0118, + .debounce_regs = 0x0130, + .tolerance_regs = 0x012c, + .cmdsrc_regs = 0x0110, + .names = { "Q", "R", "S", "T" }, + }, + { + .val_regs = 0x0088, + .rdata_reg = 0x00d4, + .irq_regs = 0x0148, + .debounce_regs = 0x0160, + .tolerance_regs = 0x015c, + .cmdsrc_regs = 0x0140, + .names = { "U", "V", "W", "X" }, + }, + { + .val_regs = 0x01E0, + .rdata_reg = 0x00d8, + .irq_regs = 0x0178, + .debounce_regs = 0x0190, + .tolerance_regs = 0x018c, + .cmdsrc_regs = 0x0170, + .names = { "Y", "Z", "AA", "AB" }, + }, + { + .val_regs = 0x01e8, + .rdata_reg = 0x00dc, + .irq_regs = 0x01a8, + .debounce_regs = 0x01c0, + .tolerance_regs = 0x01bc, + .cmdsrc_regs = 0x01a0, + .names = { "AC", "", "", "" }, + }, +}; + +enum aspeed_gpio_reg { + reg_val, + reg_rdata, + reg_dir, + reg_irq_enable, + reg_irq_type0, + reg_irq_type1, + reg_irq_type2, + reg_irq_status, + reg_debounce_sel1, + reg_debounce_sel2, + reg_tolerance, + reg_cmdsrc0, + reg_cmdsrc1, +}; + +#define GPIO_VAL_VALUE 0x00 +#define GPIO_VAL_DIR 0x04 + +#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 + +#define GPIO_DEBOUNCE_SEL1 0x00 +#define GPIO_DEBOUNCE_SEL2 0x04 + +#define GPIO_CMDSRC_0 0x00 +#define GPIO_CMDSRC_1 0x04 +#define GPIO_CMDSRC_ARM 0 +#define GPIO_CMDSRC_LPC 1 +#define GPIO_CMDSRC_COLDFIRE 2 +#define GPIO_CMDSRC_RESERVED 3 + +/* This will be resolved at compile time */ +static inline void __iomem *bank_reg(struct aspeed_gpio *gpio, + const struct aspeed_gpio_bank *bank, + const enum aspeed_gpio_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_dir: + return gpio->base + bank->val_regs + GPIO_VAL_DIR; + 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; + case reg_debounce_sel1: + return gpio->base + bank->debounce_regs + GPIO_DEBOUNCE_SEL1; + case reg_debounce_sel2: + return gpio->base + bank->debounce_regs + GPIO_DEBOUNCE_SEL2; + case reg_tolerance: + return gpio->base + bank->tolerance_regs; + case reg_cmdsrc0: + return gpio->base + bank->cmdsrc_regs + GPIO_CMDSRC_0; + case reg_cmdsrc1: + return gpio->base + bank->cmdsrc_regs + GPIO_CMDSRC_1; + } + BUG(); +} + +#define GPIO_BANK(x) ((x) >> 5) +#define GPIO_OFFSET(x) ((x) & 0x1f) +#define GPIO_BIT(x) BIT(GPIO_OFFSET(x)) + +#define _GPIO_SET_DEBOUNCE(t, o, i) ((!!((t) & BIT(i))) << GPIO_OFFSET(o)) +#define GPIO_SET_DEBOUNCE1(t, o) _GPIO_SET_DEBOUNCE(t, o, 1) +#define GPIO_SET_DEBOUNCE2(t, o) _GPIO_SET_DEBOUNCE(t, o, 0) + +static const struct aspeed_gpio_bank *to_bank(unsigned int offset) +{ + unsigned int bank = GPIO_BANK(offset); + + WARN_ON(bank >= ARRAY_SIZE(aspeed_gpio_banks)); + return &aspeed_gpio_banks[bank]; +} + +static inline bool is_bank_props_sentinel(const struct aspeed_bank_props *props) +{ + return !(props->input || props->output); +} + +static inline const struct aspeed_bank_props *find_bank_props( + struct aspeed_gpio *gpio, unsigned int offset) +{ + const struct aspeed_bank_props *props = gpio->config->props; + + while (!is_bank_props_sentinel(props)) { + if (props->bank == GPIO_BANK(offset)) + return props; + props++; + } + + return NULL; +} + +static inline bool have_gpio(struct aspeed_gpio *gpio, unsigned int offset) +{ + const struct aspeed_bank_props *props = find_bank_props(gpio, offset); + const struct aspeed_gpio_bank *bank = to_bank(offset); + unsigned int group = GPIO_OFFSET(offset) / 8; + + return bank->names[group][0] != '\0' && + (!props || ((props->input | props->output) & GPIO_BIT(offset))); +} + +static inline bool have_input(struct aspeed_gpio *gpio, unsigned int offset) +{ + const struct aspeed_bank_props *props = find_bank_props(gpio, offset); + + return !props || (props->input & GPIO_BIT(offset)); +} + +#define have_irq(g, o) have_input((g), (o)) +#define have_debounce(g, o) have_input((g), (o)) + +static inline bool have_output(struct aspeed_gpio *gpio, unsigned int offset) +{ + const struct aspeed_bank_props *props = find_bank_props(gpio, offset); + + return !props || (props->output & GPIO_BIT(offset)); +} + +static void aspeed_gpio_change_cmd_source(struct aspeed_gpio *gpio, + const struct aspeed_gpio_bank *bank, + int bindex, int cmdsrc) +{ + void __iomem *c0 = bank_reg(gpio, bank, reg_cmdsrc0); + void __iomem *c1 = bank_reg(gpio, bank, reg_cmdsrc1); + u32 bit, reg; + + /* + * Each register controls 4 banks, so take the bottom 2 + * bits of the bank index, and use them to select the + * right control bit (0, 8, 16 or 24). + */ + bit = BIT((bindex & 3) << 3); + + /* Source 1 first to avoid illegal 11 combination */ + reg = ioread32(c1); + if (cmdsrc & 2) + reg |= bit; + else + reg &= ~bit; + iowrite32(reg, c1); + + /* Then Source 0 */ + reg = ioread32(c0); + if (cmdsrc & 1) + reg |= bit; + else + reg &= ~bit; + iowrite32(reg, c0); +} + +static bool aspeed_gpio_copro_request(struct aspeed_gpio *gpio, + unsigned int offset) +{ + const struct aspeed_gpio_bank *bank = to_bank(offset); + + if (!copro_ops || !gpio->cf_copro_bankmap) + return false; + if (!gpio->cf_copro_bankmap[offset >> 3]) + return false; + if (!copro_ops->request_access) + return false; + + /* Pause the coprocessor */ + copro_ops->request_access(copro_data); + + /* Change command source back to ARM */ + aspeed_gpio_change_cmd_source(gpio, bank, offset >> 3, GPIO_CMDSRC_ARM); + + /* Update cache */ + gpio->dcache[GPIO_BANK(offset)] = ioread32(bank_reg(gpio, bank, reg_rdata)); + + return true; +} + +static void aspeed_gpio_copro_release(struct aspeed_gpio *gpio, + unsigned int offset) +{ + const struct aspeed_gpio_bank *bank = to_bank(offset); + + if (!copro_ops || !gpio->cf_copro_bankmap) + return; + if (!gpio->cf_copro_bankmap[offset >> 3]) + return; + if (!copro_ops->release_access) + return; + + /* Change command source back to ColdFire */ + aspeed_gpio_change_cmd_source(gpio, bank, offset >> 3, + GPIO_CMDSRC_COLDFIRE); + + /* Restart the coprocessor */ + copro_ops->release_access(copro_data); +} + +static int aspeed_gpio_get(struct gpio_chip *gc, unsigned int offset) +{ + struct aspeed_gpio *gpio = gpiochip_get_data(gc); + const struct aspeed_gpio_bank *bank = to_bank(offset); + + return !!(ioread32(bank_reg(gpio, bank, reg_val)) & GPIO_BIT(offset)); +} + +static void __aspeed_gpio_set(struct gpio_chip *gc, unsigned int offset, + int val) +{ + struct aspeed_gpio *gpio = gpiochip_get_data(gc); + const struct aspeed_gpio_bank *bank = to_bank(offset); + void __iomem *addr; + u32 reg; + + addr = bank_reg(gpio, bank, reg_val); + reg = gpio->dcache[GPIO_BANK(offset)]; + + if (val) + reg |= GPIO_BIT(offset); + else + reg &= ~GPIO_BIT(offset); + gpio->dcache[GPIO_BANK(offset)] = reg; + + iowrite32(reg, addr); +} + +static void aspeed_gpio_set(struct gpio_chip *gc, unsigned int offset, + int val) +{ + struct aspeed_gpio *gpio = gpiochip_get_data(gc); + unsigned long flags; + bool copro; + + raw_spin_lock_irqsave(&gpio->lock, flags); + copro = aspeed_gpio_copro_request(gpio, offset); + + __aspeed_gpio_set(gc, offset, val); + + if (copro) + aspeed_gpio_copro_release(gpio, offset); + raw_spin_unlock_irqrestore(&gpio->lock, flags); +} + +static int aspeed_gpio_dir_in(struct gpio_chip *gc, unsigned int offset) +{ + struct aspeed_gpio *gpio = gpiochip_get_data(gc); + const struct aspeed_gpio_bank *bank = to_bank(offset); + void __iomem *addr = bank_reg(gpio, bank, reg_dir); + unsigned long flags; + bool copro; + u32 reg; + + if (!have_input(gpio, offset)) + return -ENOTSUPP; + + raw_spin_lock_irqsave(&gpio->lock, flags); + + reg = ioread32(addr); + reg &= ~GPIO_BIT(offset); + + copro = aspeed_gpio_copro_request(gpio, offset); + iowrite32(reg, addr); + if (copro) + aspeed_gpio_copro_release(gpio, offset); + + raw_spin_unlock_irqrestore(&gpio->lock, flags); + + return 0; +} + +static int aspeed_gpio_dir_out(struct gpio_chip *gc, + unsigned int offset, int val) +{ + struct aspeed_gpio *gpio = gpiochip_get_data(gc); + const struct aspeed_gpio_bank *bank = to_bank(offset); + void __iomem *addr = bank_reg(gpio, bank, reg_dir); + unsigned long flags; + bool copro; + u32 reg; + + if (!have_output(gpio, offset)) + return -ENOTSUPP; + + raw_spin_lock_irqsave(&gpio->lock, flags); + + reg = ioread32(addr); + reg |= GPIO_BIT(offset); + + copro = aspeed_gpio_copro_request(gpio, offset); + __aspeed_gpio_set(gc, offset, val); + iowrite32(reg, addr); + + if (copro) + aspeed_gpio_copro_release(gpio, offset); + raw_spin_unlock_irqrestore(&gpio->lock, flags); + + return 0; +} + +static int aspeed_gpio_get_direction(struct gpio_chip *gc, unsigned int offset) +{ + struct aspeed_gpio *gpio = gpiochip_get_data(gc); + const struct aspeed_gpio_bank *bank = to_bank(offset); + unsigned long flags; + u32 val; + + if (!have_input(gpio, offset)) + return GPIO_LINE_DIRECTION_OUT; + + if (!have_output(gpio, offset)) + return GPIO_LINE_DIRECTION_IN; + + raw_spin_lock_irqsave(&gpio->lock, flags); + + val = ioread32(bank_reg(gpio, bank, reg_dir)) & GPIO_BIT(offset); + + raw_spin_unlock_irqrestore(&gpio->lock, flags); + + return val ? GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN; +} + +static inline int irqd_to_aspeed_gpio_data(struct irq_data *d, + struct aspeed_gpio **gpio, + const struct aspeed_gpio_bank **bank, + u32 *bit, int *offset) +{ + struct aspeed_gpio *internal; + + *offset = irqd_to_hwirq(d); + + internal = irq_data_get_irq_chip_data(d); + + /* This might be a bit of a questionable place to check */ + if (!have_irq(internal, *offset)) + return -ENOTSUPP; + + *gpio = internal; + *bank = to_bank(*offset); + *bit = GPIO_BIT(*offset); + + return 0; +} + +static void aspeed_gpio_irq_ack(struct irq_data *d) +{ + const struct aspeed_gpio_bank *bank; + struct aspeed_gpio *gpio; + unsigned long flags; + void __iomem *status_addr; + int rc, offset; + bool copro; + u32 bit; + + rc = irqd_to_aspeed_gpio_data(d, &gpio, &bank, &bit, &offset); + if (rc) + return; + + status_addr = bank_reg(gpio, bank, reg_irq_status); + + raw_spin_lock_irqsave(&gpio->lock, flags); + copro = aspeed_gpio_copro_request(gpio, offset); + + iowrite32(bit, status_addr); + + if (copro) + aspeed_gpio_copro_release(gpio, offset); + raw_spin_unlock_irqrestore(&gpio->lock, flags); +} + +static void aspeed_gpio_irq_set_mask(struct irq_data *d, bool set) +{ + const struct aspeed_gpio_bank *bank; + struct aspeed_gpio *gpio; + unsigned long flags; + u32 reg, bit; + void __iomem *addr; + int rc, offset; + bool copro; + + rc = irqd_to_aspeed_gpio_data(d, &gpio, &bank, &bit, &offset); + if (rc) + return; + + addr = bank_reg(gpio, bank, reg_irq_enable); + + raw_spin_lock_irqsave(&gpio->lock, flags); + copro = aspeed_gpio_copro_request(gpio, offset); + + reg = ioread32(addr); + if (set) + reg |= bit; + else + reg &= ~bit; + iowrite32(reg, addr); + + if (copro) + aspeed_gpio_copro_release(gpio, offset); + raw_spin_unlock_irqrestore(&gpio->lock, flags); +} + +static void aspeed_gpio_irq_mask(struct irq_data *d) +{ + aspeed_gpio_irq_set_mask(d, false); +} + +static void aspeed_gpio_irq_unmask(struct irq_data *d) +{ + aspeed_gpio_irq_set_mask(d, true); +} + +static int aspeed_gpio_set_type(struct irq_data *d, unsigned int type) +{ + u32 type0 = 0; + u32 type1 = 0; + u32 type2 = 0; + u32 bit, reg; + const struct aspeed_gpio_bank *bank; + irq_flow_handler_t handler; + struct aspeed_gpio *gpio; + unsigned long flags; + void __iomem *addr; + int rc, offset; + bool copro; + + rc = irqd_to_aspeed_gpio_data(d, &gpio, &bank, &bit, &offset); + if (rc) + return -EINVAL; + + 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; + } + + raw_spin_lock_irqsave(&gpio->lock, flags); + copro = aspeed_gpio_copro_request(gpio, offset); + + 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); + + if (copro) + aspeed_gpio_copro_release(gpio, offset); + raw_spin_unlock_irqrestore(&gpio->lock, flags); + + irq_set_handler_locked(d, handler); + + return 0; +} + +static void aspeed_gpio_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_gpio *data = gpiochip_get_data(gc); + unsigned int i, p, banks; + unsigned long reg; + struct aspeed_gpio *gpio = gpiochip_get_data(gc); + + chained_irq_enter(ic, desc); + + banks = DIV_ROUND_UP(gpio->chip.ngpio, 32); + for (i = 0; i < banks; i++) { + const struct aspeed_gpio_bank *bank = &aspeed_gpio_banks[i]; + + reg = ioread32(bank_reg(data, bank, reg_irq_status)); + + for_each_set_bit(p, ®, 32) + generic_handle_domain_irq(gc->irq.domain, i * 32 + p); + } + + chained_irq_exit(ic, desc); +} + +static void aspeed_init_irq_valid_mask(struct gpio_chip *gc, + unsigned long *valid_mask, + unsigned int ngpios) +{ + struct aspeed_gpio *gpio = gpiochip_get_data(gc); + const struct aspeed_bank_props *props = gpio->config->props; + + while (!is_bank_props_sentinel(props)) { + unsigned int offset; + const unsigned long int input = props->input; + + /* Pretty crummy approach, but similar to GPIO core */ + for_each_clear_bit(offset, &input, 32) { + unsigned int i = props->bank * 32 + offset; + + if (i >= gpio->chip.ngpio) + break; + + clear_bit(i, valid_mask); + } + + props++; + } +} + +static int aspeed_gpio_reset_tolerance(struct gpio_chip *chip, + unsigned int offset, bool enable) +{ + struct aspeed_gpio *gpio = gpiochip_get_data(chip); + unsigned long flags; + void __iomem *treg; + bool copro; + u32 val; + + treg = bank_reg(gpio, to_bank(offset), reg_tolerance); + + raw_spin_lock_irqsave(&gpio->lock, flags); + copro = aspeed_gpio_copro_request(gpio, offset); + + val = readl(treg); + + if (enable) + val |= GPIO_BIT(offset); + else + val &= ~GPIO_BIT(offset); + + writel(val, treg); + + if (copro) + aspeed_gpio_copro_release(gpio, offset); + raw_spin_unlock_irqrestore(&gpio->lock, flags); + + return 0; +} + +static int aspeed_gpio_request(struct gpio_chip *chip, unsigned int offset) +{ + if (!have_gpio(gpiochip_get_data(chip), offset)) + return -ENODEV; + + return pinctrl_gpio_request(chip->base + offset); +} + +static void aspeed_gpio_free(struct gpio_chip *chip, unsigned int offset) +{ + pinctrl_gpio_free(chip->base + offset); +} + +static int usecs_to_cycles(struct aspeed_gpio *gpio, unsigned long usecs, + u32 *cycles) +{ + u64 rate; + u64 n; + u32 r; + + rate = clk_get_rate(gpio->clk); + if (!rate) + return -ENOTSUPP; + + n = rate * usecs; + r = do_div(n, 1000000); + + if (n >= U32_MAX) + return -ERANGE; + + /* At least as long as the requested time */ + *cycles = n + (!!r); + + return 0; +} + +/* Call under gpio->lock */ +static int register_allocated_timer(struct aspeed_gpio *gpio, + unsigned int offset, unsigned int timer) +{ + if (WARN(gpio->offset_timer[offset] != 0, + "Offset %d already allocated timer %d\n", + offset, gpio->offset_timer[offset])) + return -EINVAL; + + if (WARN(gpio->timer_users[timer] == UINT_MAX, + "Timer user count would overflow\n")) + return -EPERM; + + gpio->offset_timer[offset] = timer; + gpio->timer_users[timer]++; + + return 0; +} + +/* Call under gpio->lock */ +static int unregister_allocated_timer(struct aspeed_gpio *gpio, + unsigned int offset) +{ + if (WARN(gpio->offset_timer[offset] == 0, + "No timer allocated to offset %d\n", offset)) + return -EINVAL; + + if (WARN(gpio->timer_users[gpio->offset_timer[offset]] == 0, + "No users recorded for timer %d\n", + gpio->offset_timer[offset])) + return -EINVAL; + + gpio->timer_users[gpio->offset_timer[offset]]--; + gpio->offset_timer[offset] = 0; + + return 0; +} + +/* Call under gpio->lock */ +static inline bool timer_allocation_registered(struct aspeed_gpio *gpio, + unsigned int offset) +{ + return gpio->offset_timer[offset] > 0; +} + +/* Call under gpio->lock */ +static void configure_timer(struct aspeed_gpio *gpio, unsigned int offset, + unsigned int timer) +{ + const struct aspeed_gpio_bank *bank = to_bank(offset); + const u32 mask = GPIO_BIT(offset); + void __iomem *addr; + u32 val; + + /* Note: Debounce timer isn't under control of the command + * source registers, so no need to sync with the coprocessor + */ + addr = bank_reg(gpio, bank, reg_debounce_sel1); + val = ioread32(addr); + iowrite32((val & ~mask) | GPIO_SET_DEBOUNCE1(timer, offset), addr); + + addr = bank_reg(gpio, bank, reg_debounce_sel2); + val = ioread32(addr); + iowrite32((val & ~mask) | GPIO_SET_DEBOUNCE2(timer, offset), addr); +} + +static int enable_debounce(struct gpio_chip *chip, unsigned int offset, + unsigned long usecs) +{ + struct aspeed_gpio *gpio = gpiochip_get_data(chip); + u32 requested_cycles; + unsigned long flags; + int rc; + int i; + + if (!gpio->clk) + return -EINVAL; + + rc = usecs_to_cycles(gpio, usecs, &requested_cycles); + if (rc < 0) { + dev_warn(chip->parent, "Failed to convert %luus to cycles at %luHz: %d\n", + usecs, clk_get_rate(gpio->clk), rc); + return rc; + } + + raw_spin_lock_irqsave(&gpio->lock, flags); + + if (timer_allocation_registered(gpio, offset)) { + rc = unregister_allocated_timer(gpio, offset); + if (rc < 0) + goto out; + } + + /* Try to find a timer already configured for the debounce period */ + for (i = 1; i < ARRAY_SIZE(debounce_timers); i++) { + u32 cycles; + + cycles = ioread32(gpio->base + debounce_timers[i]); + if (requested_cycles == cycles) + break; + } + + if (i == ARRAY_SIZE(debounce_timers)) { + int j; + + /* + * As there are no timers configured for the requested debounce + * period, find an unused timer instead + */ + for (j = 1; j < ARRAY_SIZE(gpio->timer_users); j++) { + if (gpio->timer_users[j] == 0) + break; + } + + if (j == ARRAY_SIZE(gpio->timer_users)) { + dev_warn(chip->parent, + "Debounce timers exhausted, cannot debounce for period %luus\n", + usecs); + + rc = -EPERM; + + /* + * We already adjusted the accounting to remove @offset + * as a user of its previous timer, so also configure + * the hardware so @offset has timers disabled for + * consistency. + */ + configure_timer(gpio, offset, 0); + goto out; + } + + i = j; + + iowrite32(requested_cycles, gpio->base + debounce_timers[i]); + } + + if (WARN(i == 0, "Cannot register index of disabled timer\n")) { + rc = -EINVAL; + goto out; + } + + register_allocated_timer(gpio, offset, i); + configure_timer(gpio, offset, i); + +out: + raw_spin_unlock_irqrestore(&gpio->lock, flags); + + return rc; +} + +static int disable_debounce(struct gpio_chip *chip, unsigned int offset) +{ + struct aspeed_gpio *gpio = gpiochip_get_data(chip); + unsigned long flags; + int rc; + + raw_spin_lock_irqsave(&gpio->lock, flags); + + rc = unregister_allocated_timer(gpio, offset); + if (!rc) + configure_timer(gpio, offset, 0); + + raw_spin_unlock_irqrestore(&gpio->lock, flags); + + return rc; +} + +static int set_debounce(struct gpio_chip *chip, unsigned int offset, + unsigned long usecs) +{ + struct aspeed_gpio *gpio = gpiochip_get_data(chip); + + if (!have_debounce(gpio, offset)) + return -ENOTSUPP; + + if (usecs) + return enable_debounce(chip, offset, usecs); + + return disable_debounce(chip, offset); +} + +static int aspeed_gpio_set_config(struct gpio_chip *chip, unsigned int offset, + unsigned long config) +{ + unsigned long param = pinconf_to_config_param(config); + u32 arg = pinconf_to_config_argument(config); + + if (param == PIN_CONFIG_INPUT_DEBOUNCE) + return set_debounce(chip, offset, arg); + else if (param == PIN_CONFIG_BIAS_DISABLE || + param == PIN_CONFIG_BIAS_PULL_DOWN || + param == PIN_CONFIG_DRIVE_STRENGTH) + return pinctrl_gpio_set_config(chip->base + offset, config); + else if (param == PIN_CONFIG_DRIVE_OPEN_DRAIN || + param == PIN_CONFIG_DRIVE_OPEN_SOURCE) + /* Return -ENOTSUPP to trigger emulation, as per datasheet */ + return -ENOTSUPP; + else if (param == PIN_CONFIG_PERSIST_STATE) + return aspeed_gpio_reset_tolerance(chip, offset, arg); + + return -ENOTSUPP; +} + +/** + * aspeed_gpio_copro_set_ops - Sets the callbacks used for handshaking with + * the coprocessor for shared GPIO banks + * @ops: The callbacks + * @data: Pointer passed back to the callbacks + */ +int aspeed_gpio_copro_set_ops(const struct aspeed_gpio_copro_ops *ops, void *data) +{ + copro_data = data; + copro_ops = ops; + + return 0; +} +EXPORT_SYMBOL_GPL(aspeed_gpio_copro_set_ops); + +/** + * aspeed_gpio_copro_grab_gpio - Mark a GPIO used by the coprocessor. The entire + * bank gets marked and any access from the ARM will + * result in handshaking via callbacks. + * @desc: The GPIO to be marked + * @vreg_offset: If non-NULL, returns the value register offset in the GPIO space + * @dreg_offset: If non-NULL, returns the data latch register offset in the GPIO space + * @bit: If non-NULL, returns the bit number of the GPIO in the registers + */ +int aspeed_gpio_copro_grab_gpio(struct gpio_desc *desc, + u16 *vreg_offset, u16 *dreg_offset, u8 *bit) +{ + struct gpio_chip *chip = gpiod_to_chip(desc); + struct aspeed_gpio *gpio = gpiochip_get_data(chip); + int rc = 0, bindex, offset = gpio_chip_hwgpio(desc); + const struct aspeed_gpio_bank *bank = to_bank(offset); + unsigned long flags; + + if (!gpio->cf_copro_bankmap) + gpio->cf_copro_bankmap = kzalloc(gpio->chip.ngpio >> 3, GFP_KERNEL); + if (!gpio->cf_copro_bankmap) + return -ENOMEM; + if (offset < 0 || offset > gpio->chip.ngpio) + return -EINVAL; + bindex = offset >> 3; + + raw_spin_lock_irqsave(&gpio->lock, flags); + + /* Sanity check, this shouldn't happen */ + if (gpio->cf_copro_bankmap[bindex] == 0xff) { + rc = -EIO; + goto bail; + } + gpio->cf_copro_bankmap[bindex]++; + + /* Switch command source */ + if (gpio->cf_copro_bankmap[bindex] == 1) + aspeed_gpio_change_cmd_source(gpio, bank, bindex, + GPIO_CMDSRC_COLDFIRE); + + if (vreg_offset) + *vreg_offset = bank->val_regs; + if (dreg_offset) + *dreg_offset = bank->rdata_reg; + if (bit) + *bit = GPIO_OFFSET(offset); + bail: + raw_spin_unlock_irqrestore(&gpio->lock, flags); + return rc; +} +EXPORT_SYMBOL_GPL(aspeed_gpio_copro_grab_gpio); + +/** + * aspeed_gpio_copro_release_gpio - Unmark a GPIO used by the coprocessor. + * @desc: The GPIO to be marked + */ +int aspeed_gpio_copro_release_gpio(struct gpio_desc *desc) +{ + struct gpio_chip *chip = gpiod_to_chip(desc); + struct aspeed_gpio *gpio = gpiochip_get_data(chip); + int rc = 0, bindex, offset = gpio_chip_hwgpio(desc); + const struct aspeed_gpio_bank *bank = to_bank(offset); + unsigned long flags; + + if (!gpio->cf_copro_bankmap) + return -ENXIO; + + if (offset < 0 || offset > gpio->chip.ngpio) + return -EINVAL; + bindex = offset >> 3; + + raw_spin_lock_irqsave(&gpio->lock, flags); + + /* Sanity check, this shouldn't happen */ + if (gpio->cf_copro_bankmap[bindex] == 0) { + rc = -EIO; + goto bail; + } + gpio->cf_copro_bankmap[bindex]--; + + /* Switch command source */ + if (gpio->cf_copro_bankmap[bindex] == 0) + aspeed_gpio_change_cmd_source(gpio, bank, bindex, + GPIO_CMDSRC_ARM); + bail: + raw_spin_unlock_irqrestore(&gpio->lock, flags); + return rc; +} +EXPORT_SYMBOL_GPL(aspeed_gpio_copro_release_gpio); + +/* + * Any banks not specified in a struct aspeed_bank_props array are assumed to + * have the properties: + * + * { .input = 0xffffffff, .output = 0xffffffff } + */ + +static const struct aspeed_bank_props ast2400_bank_props[] = { + /* input output */ + { 5, 0xffffffff, 0x0000ffff }, /* U/V/W/X */ + { 6, 0x0000000f, 0x0fffff0f }, /* Y/Z/AA/AB, two 4-GPIO holes */ + { }, +}; + +static const struct aspeed_gpio_config ast2400_config = + /* 220 for simplicity, really 216 with two 4-GPIO holes, four at end */ + { .nr_gpios = 220, .props = ast2400_bank_props, }; + +static const struct aspeed_bank_props ast2500_bank_props[] = { + /* input output */ + { 5, 0xffffffff, 0x0000ffff }, /* U/V/W/X */ + { 6, 0x0fffffff, 0x0fffffff }, /* Y/Z/AA/AB, 4-GPIO hole */ + { 7, 0x000000ff, 0x000000ff }, /* AC */ + { }, +}; + +static const struct aspeed_gpio_config ast2500_config = + /* 232 for simplicity, actual number is 228 (4-GPIO hole in GPIOAB) */ + { .nr_gpios = 232, .props = ast2500_bank_props, }; + +static const struct aspeed_bank_props ast2600_bank_props[] = { + /* input output */ + {4, 0xffffffff, 0x00ffffff}, /* Q/R/S/T */ + {5, 0xffffffff, 0xffffff00}, /* U/V/W/X */ + {6, 0x0000ffff, 0x0000ffff}, /* Y/Z */ + { }, +}; + +static const struct aspeed_gpio_config ast2600_config = + /* + * ast2600 has two controllers one with 208 GPIOs and one with 36 GPIOs. + * We expect ngpio being set in the device tree and this is a fallback + * option. + */ + { .nr_gpios = 208, .props = ast2600_bank_props, }; + +static const struct of_device_id aspeed_gpio_of_table[] = { + { .compatible = "aspeed,ast2400-gpio", .data = &ast2400_config, }, + { .compatible = "aspeed,ast2500-gpio", .data = &ast2500_config, }, + { .compatible = "aspeed,ast2600-gpio", .data = &ast2600_config, }, + {} +}; +MODULE_DEVICE_TABLE(of, aspeed_gpio_of_table); + +static int __init aspeed_gpio_probe(struct platform_device *pdev) +{ + const struct of_device_id *gpio_id; + struct aspeed_gpio *gpio; + int rc, i, banks, err; + u32 ngpio; + + 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); + + raw_spin_lock_init(&gpio->lock); + + gpio_id = of_match_node(aspeed_gpio_of_table, pdev->dev.of_node); + if (!gpio_id) + return -EINVAL; + + gpio->clk = of_clk_get(pdev->dev.of_node, 0); + if (IS_ERR(gpio->clk)) { + dev_warn(&pdev->dev, + "Failed to get clock from devicetree, debouncing disabled\n"); + gpio->clk = NULL; + } + + gpio->config = gpio_id->data; + + gpio->chip.parent = &pdev->dev; + err = of_property_read_u32(pdev->dev.of_node, "ngpios", &ngpio); + gpio->chip.ngpio = (u16) ngpio; + if (err) + gpio->chip.ngpio = gpio->config->nr_gpios; + gpio->chip.direction_input = aspeed_gpio_dir_in; + gpio->chip.direction_output = aspeed_gpio_dir_out; + gpio->chip.get_direction = aspeed_gpio_get_direction; + gpio->chip.request = aspeed_gpio_request; + gpio->chip.free = aspeed_gpio_free; + gpio->chip.get = aspeed_gpio_get; + gpio->chip.set = aspeed_gpio_set; + gpio->chip.set_config = aspeed_gpio_set_config; + gpio->chip.label = dev_name(&pdev->dev); + gpio->chip.base = -1; + + /* Allocate a cache of the output registers */ + banks = DIV_ROUND_UP(gpio->chip.ngpio, 32); + gpio->dcache = devm_kcalloc(&pdev->dev, + banks, sizeof(u32), GFP_KERNEL); + if (!gpio->dcache) + return -ENOMEM; + + /* + * Populate it with initial values read from the HW and switch + * all command sources to the ARM by default + */ + for (i = 0; i < banks; i++) { + const struct aspeed_gpio_bank *bank = &aspeed_gpio_banks[i]; + void __iomem *addr = bank_reg(gpio, bank, reg_rdata); + gpio->dcache[i] = ioread32(addr); + aspeed_gpio_change_cmd_source(gpio, bank, 0, GPIO_CMDSRC_ARM); + aspeed_gpio_change_cmd_source(gpio, bank, 1, GPIO_CMDSRC_ARM); + aspeed_gpio_change_cmd_source(gpio, bank, 2, GPIO_CMDSRC_ARM); + aspeed_gpio_change_cmd_source(gpio, bank, 3, GPIO_CMDSRC_ARM); + } + + /* Optionally set up an irqchip if there is an IRQ */ + rc = platform_get_irq(pdev, 0); + if (rc > 0) { + struct gpio_irq_chip *girq; + + gpio->irq = rc; + girq = &gpio->chip.irq; + girq->chip = &gpio->irqc; + girq->chip->name = dev_name(&pdev->dev); + girq->chip->irq_ack = aspeed_gpio_irq_ack; + girq->chip->irq_mask = aspeed_gpio_irq_mask; + girq->chip->irq_unmask = aspeed_gpio_irq_unmask; + girq->chip->irq_set_type = aspeed_gpio_set_type; + girq->parent_handler = aspeed_gpio_irq_handler; + girq->num_parents = 1; + girq->parents = devm_kcalloc(&pdev->dev, 1, + sizeof(*girq->parents), + GFP_KERNEL); + if (!girq->parents) + return -ENOMEM; + girq->parents[0] = gpio->irq; + girq->default_type = IRQ_TYPE_NONE; + girq->handler = handle_bad_irq; + girq->init_valid_mask = aspeed_init_irq_valid_mask; + } + + gpio->offset_timer = + devm_kzalloc(&pdev->dev, gpio->chip.ngpio, GFP_KERNEL); + if (!gpio->offset_timer) + return -ENOMEM; + + rc = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio); + if (rc < 0) + return rc; + + return 0; +} + +static struct platform_driver aspeed_gpio_driver = { + .driver = { + .name = KBUILD_MODNAME, + .of_match_table = aspeed_gpio_of_table, + }, +}; + +module_platform_driver_probe(aspeed_gpio_driver, aspeed_gpio_probe); + +MODULE_DESCRIPTION("Aspeed GPIO Driver"); +MODULE_LICENSE("GPL"); |