diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/pinctrl/spear/pinctrl-plgpio.c | 718 |
1 files changed, 718 insertions, 0 deletions
diff --git a/drivers/pinctrl/spear/pinctrl-plgpio.c b/drivers/pinctrl/spear/pinctrl-plgpio.c new file mode 100644 index 000000000..9d906474f --- /dev/null +++ b/drivers/pinctrl/spear/pinctrl-plgpio.c @@ -0,0 +1,718 @@ +/* + * SPEAr platform PLGPIO driver + * + * Copyright (C) 2012 ST Microelectronics + * Viresh Kumar <viresh.kumar@linaro.org> + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/gpio/driver.h> +#include <linux/io.h> +#include <linux/init.h> +#include <linux/of.h> +#include <linux/of_platform.h> +#include <linux/pinctrl/consumer.h> +#include <linux/platform_device.h> +#include <linux/pm.h> +#include <linux/spinlock.h> + +#define MAX_GPIO_PER_REG 32 +#define PIN_OFFSET(pin) (pin % MAX_GPIO_PER_REG) +#define REG_OFFSET(base, reg, pin) (base + reg + (pin / MAX_GPIO_PER_REG) \ + * sizeof(int *)) + +/* + * plgpio pins in all machines are not one to one mapped, bitwise with registers + * bits. These set of macros define register masks for which below functions + * (pin_to_offset and offset_to_pin) are required to be called. + */ +#define PTO_ENB_REG 0x001 +#define PTO_WDATA_REG 0x002 +#define PTO_DIR_REG 0x004 +#define PTO_IE_REG 0x008 +#define PTO_RDATA_REG 0x010 +#define PTO_MIS_REG 0x020 + +struct plgpio_regs { + u32 enb; /* enable register */ + u32 wdata; /* write data register */ + u32 dir; /* direction set register */ + u32 rdata; /* read data register */ + u32 ie; /* interrupt enable register */ + u32 mis; /* mask interrupt status register */ + u32 eit; /* edge interrupt type */ +}; + +/* + * struct plgpio: plgpio driver specific structure + * + * lock: lock for guarding gpio registers + * base: base address of plgpio block + * chip: gpio framework specific chip information structure + * p2o: function ptr for pin to offset conversion. This is required only for + * machines where mapping b/w pin and offset is not 1-to-1. + * o2p: function ptr for offset to pin conversion. This is required only for + * machines where mapping b/w pin and offset is not 1-to-1. + * p2o_regs: mask of registers for which p2o and o2p are applicable + * regs: register offsets + * csave_regs: context save registers for standby/sleep/hibernate cases + */ +struct plgpio { + spinlock_t lock; + void __iomem *base; + struct clk *clk; + struct gpio_chip chip; + int (*p2o)(int pin); /* pin_to_offset */ + int (*o2p)(int offset); /* offset_to_pin */ + u32 p2o_regs; + struct plgpio_regs regs; +#ifdef CONFIG_PM_SLEEP + struct plgpio_regs *csave_regs; +#endif +}; + +/* register manipulation inline functions */ +static inline u32 is_plgpio_set(void __iomem *base, u32 pin, u32 reg) +{ + u32 offset = PIN_OFFSET(pin); + void __iomem *reg_off = REG_OFFSET(base, reg, pin); + u32 val = readl_relaxed(reg_off); + + return !!(val & (1 << offset)); +} + +static inline void plgpio_reg_set(void __iomem *base, u32 pin, u32 reg) +{ + u32 offset = PIN_OFFSET(pin); + void __iomem *reg_off = REG_OFFSET(base, reg, pin); + u32 val = readl_relaxed(reg_off); + + writel_relaxed(val | (1 << offset), reg_off); +} + +static inline void plgpio_reg_reset(void __iomem *base, u32 pin, u32 reg) +{ + u32 offset = PIN_OFFSET(pin); + void __iomem *reg_off = REG_OFFSET(base, reg, pin); + u32 val = readl_relaxed(reg_off); + + writel_relaxed(val & ~(1 << offset), reg_off); +} + +/* gpio framework specific routines */ +static int plgpio_direction_input(struct gpio_chip *chip, unsigned offset) +{ + struct plgpio *plgpio = gpiochip_get_data(chip); + unsigned long flags; + + /* get correct offset for "offset" pin */ + if (plgpio->p2o && (plgpio->p2o_regs & PTO_DIR_REG)) { + offset = plgpio->p2o(offset); + if (offset == -1) + return -EINVAL; + } + + spin_lock_irqsave(&plgpio->lock, flags); + plgpio_reg_set(plgpio->base, offset, plgpio->regs.dir); + spin_unlock_irqrestore(&plgpio->lock, flags); + + return 0; +} + +static int plgpio_direction_output(struct gpio_chip *chip, unsigned offset, + int value) +{ + struct plgpio *plgpio = gpiochip_get_data(chip); + unsigned long flags; + unsigned dir_offset = offset, wdata_offset = offset, tmp; + + /* get correct offset for "offset" pin */ + if (plgpio->p2o && (plgpio->p2o_regs & (PTO_DIR_REG | PTO_WDATA_REG))) { + tmp = plgpio->p2o(offset); + if (tmp == -1) + return -EINVAL; + + if (plgpio->p2o_regs & PTO_DIR_REG) + dir_offset = tmp; + if (plgpio->p2o_regs & PTO_WDATA_REG) + wdata_offset = tmp; + } + + spin_lock_irqsave(&plgpio->lock, flags); + if (value) + plgpio_reg_set(plgpio->base, wdata_offset, + plgpio->regs.wdata); + else + plgpio_reg_reset(plgpio->base, wdata_offset, + plgpio->regs.wdata); + + plgpio_reg_reset(plgpio->base, dir_offset, plgpio->regs.dir); + spin_unlock_irqrestore(&plgpio->lock, flags); + + return 0; +} + +static int plgpio_get_value(struct gpio_chip *chip, unsigned offset) +{ + struct plgpio *plgpio = gpiochip_get_data(chip); + + if (offset >= chip->ngpio) + return -EINVAL; + + /* get correct offset for "offset" pin */ + if (plgpio->p2o && (plgpio->p2o_regs & PTO_RDATA_REG)) { + offset = plgpio->p2o(offset); + if (offset == -1) + return -EINVAL; + } + + return is_plgpio_set(plgpio->base, offset, plgpio->regs.rdata); +} + +static void plgpio_set_value(struct gpio_chip *chip, unsigned offset, int value) +{ + struct plgpio *plgpio = gpiochip_get_data(chip); + + if (offset >= chip->ngpio) + return; + + /* get correct offset for "offset" pin */ + if (plgpio->p2o && (plgpio->p2o_regs & PTO_WDATA_REG)) { + offset = plgpio->p2o(offset); + if (offset == -1) + return; + } + + if (value) + plgpio_reg_set(plgpio->base, offset, plgpio->regs.wdata); + else + plgpio_reg_reset(plgpio->base, offset, plgpio->regs.wdata); +} + +static int plgpio_request(struct gpio_chip *chip, unsigned offset) +{ + struct plgpio *plgpio = gpiochip_get_data(chip); + int gpio = chip->base + offset; + unsigned long flags; + int ret = 0; + + if (offset >= chip->ngpio) + return -EINVAL; + + ret = pinctrl_gpio_request(gpio); + if (ret) + return ret; + + if (!IS_ERR(plgpio->clk)) { + ret = clk_enable(plgpio->clk); + if (ret) + goto err0; + } + + if (plgpio->regs.enb == -1) + return 0; + + /* + * put gpio in IN mode before enabling it. This make enabling gpio safe + */ + ret = plgpio_direction_input(chip, offset); + if (ret) + goto err1; + + /* get correct offset for "offset" pin */ + if (plgpio->p2o && (plgpio->p2o_regs & PTO_ENB_REG)) { + offset = plgpio->p2o(offset); + if (offset == -1) { + ret = -EINVAL; + goto err1; + } + } + + spin_lock_irqsave(&plgpio->lock, flags); + plgpio_reg_set(plgpio->base, offset, plgpio->regs.enb); + spin_unlock_irqrestore(&plgpio->lock, flags); + return 0; + +err1: + if (!IS_ERR(plgpio->clk)) + clk_disable(plgpio->clk); +err0: + pinctrl_gpio_free(gpio); + return ret; +} + +static void plgpio_free(struct gpio_chip *chip, unsigned offset) +{ + struct plgpio *plgpio = gpiochip_get_data(chip); + int gpio = chip->base + offset; + unsigned long flags; + + if (offset >= chip->ngpio) + return; + + if (plgpio->regs.enb == -1) + goto disable_clk; + + /* get correct offset for "offset" pin */ + if (plgpio->p2o && (plgpio->p2o_regs & PTO_ENB_REG)) { + offset = plgpio->p2o(offset); + if (offset == -1) + return; + } + + spin_lock_irqsave(&plgpio->lock, flags); + plgpio_reg_reset(plgpio->base, offset, plgpio->regs.enb); + spin_unlock_irqrestore(&plgpio->lock, flags); + +disable_clk: + if (!IS_ERR(plgpio->clk)) + clk_disable(plgpio->clk); + + pinctrl_gpio_free(gpio); +} + +/* PLGPIO IRQ */ +static void plgpio_irq_disable(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct plgpio *plgpio = gpiochip_get_data(gc); + int offset = d->hwirq; + unsigned long flags; + + /* get correct offset for "offset" pin */ + if (plgpio->p2o && (plgpio->p2o_regs & PTO_IE_REG)) { + offset = plgpio->p2o(offset); + if (offset == -1) + return; + } + + spin_lock_irqsave(&plgpio->lock, flags); + plgpio_reg_set(plgpio->base, offset, plgpio->regs.ie); + spin_unlock_irqrestore(&plgpio->lock, flags); +} + +static void plgpio_irq_enable(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct plgpio *plgpio = gpiochip_get_data(gc); + int offset = d->hwirq; + unsigned long flags; + + /* get correct offset for "offset" pin */ + if (plgpio->p2o && (plgpio->p2o_regs & PTO_IE_REG)) { + offset = plgpio->p2o(offset); + if (offset == -1) + return; + } + + spin_lock_irqsave(&plgpio->lock, flags); + plgpio_reg_reset(plgpio->base, offset, plgpio->regs.ie); + spin_unlock_irqrestore(&plgpio->lock, flags); +} + +static int plgpio_irq_set_type(struct irq_data *d, unsigned trigger) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct plgpio *plgpio = gpiochip_get_data(gc); + int offset = d->hwirq; + void __iomem *reg_off; + unsigned int supported_type = 0, val; + + if (offset >= plgpio->chip.ngpio) + return -EINVAL; + + if (plgpio->regs.eit == -1) + supported_type = IRQ_TYPE_LEVEL_HIGH; + else + supported_type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING; + + if (!(trigger & supported_type)) + return -EINVAL; + + if (plgpio->regs.eit == -1) + return 0; + + reg_off = REG_OFFSET(plgpio->base, plgpio->regs.eit, offset); + val = readl_relaxed(reg_off); + + offset = PIN_OFFSET(offset); + if (trigger & IRQ_TYPE_EDGE_RISING) + writel_relaxed(val | (1 << offset), reg_off); + else + writel_relaxed(val & ~(1 << offset), reg_off); + + return 0; +} + +static struct irq_chip plgpio_irqchip = { + .name = "PLGPIO", + .irq_enable = plgpio_irq_enable, + .irq_disable = plgpio_irq_disable, + .irq_set_type = plgpio_irq_set_type, +}; + +static void plgpio_irq_handler(struct irq_desc *desc) +{ + struct gpio_chip *gc = irq_desc_get_handler_data(desc); + struct plgpio *plgpio = gpiochip_get_data(gc); + struct irq_chip *irqchip = irq_desc_get_chip(desc); + int regs_count, count, pin, offset, i = 0; + unsigned long pending; + + count = plgpio->chip.ngpio; + regs_count = DIV_ROUND_UP(count, MAX_GPIO_PER_REG); + + chained_irq_enter(irqchip, desc); + /* check all plgpio MIS registers for a possible interrupt */ + for (; i < regs_count; i++) { + pending = readl_relaxed(plgpio->base + plgpio->regs.mis + + i * sizeof(int *)); + if (!pending) + continue; + + /* clear interrupts */ + writel_relaxed(~pending, plgpio->base + plgpio->regs.mis + + i * sizeof(int *)); + /* + * clear extra bits in last register having gpios < MAX/REG + * ex: Suppose there are max 102 plgpios. then last register + * must have only (102 - MAX_GPIO_PER_REG * 3) = 6 relevant bits + * so, we must not take other 28 bits into consideration for + * checking interrupt. so clear those bits. + */ + count = count - i * MAX_GPIO_PER_REG; + if (count < MAX_GPIO_PER_REG) + pending &= (1 << count) - 1; + + for_each_set_bit(offset, &pending, MAX_GPIO_PER_REG) { + /* get correct pin for "offset" */ + if (plgpio->o2p && (plgpio->p2o_regs & PTO_MIS_REG)) { + pin = plgpio->o2p(offset); + if (pin == -1) + continue; + } else + pin = offset; + + /* get correct irq line number */ + pin = i * MAX_GPIO_PER_REG + pin; + generic_handle_irq( + irq_find_mapping(gc->irq.domain, pin)); + } + } + chained_irq_exit(irqchip, desc); +} + +/* + * pin to offset and offset to pin converter functions + * + * In spear310 there is inconsistency among bit positions in plgpio regiseters, + * for different plgpio pins. For example: for pin 27, bit offset is 23, pin + * 28-33 are not supported, pin 95 has offset bit 95, bit 100 has offset bit 1 + */ +static int spear310_p2o(int pin) +{ + int offset = pin; + + if (pin <= 27) + offset += 4; + else if (pin <= 33) + offset = -1; + else if (pin <= 97) + offset -= 2; + else if (pin <= 101) + offset = 101 - pin; + else + offset = -1; + + return offset; +} + +static int spear310_o2p(int offset) +{ + if (offset <= 3) + return 101 - offset; + else if (offset <= 31) + return offset - 4; + else + return offset + 2; +} + +static int plgpio_probe_dt(struct platform_device *pdev, struct plgpio *plgpio) +{ + struct device_node *np = pdev->dev.of_node; + int ret = -EINVAL; + u32 val; + + if (of_machine_is_compatible("st,spear310")) { + plgpio->p2o = spear310_p2o; + plgpio->o2p = spear310_o2p; + plgpio->p2o_regs = PTO_WDATA_REG | PTO_DIR_REG | PTO_IE_REG | + PTO_RDATA_REG | PTO_MIS_REG; + } + + if (!of_property_read_u32(np, "st-plgpio,ngpio", &val)) { + plgpio->chip.ngpio = val; + } else { + dev_err(&pdev->dev, "DT: Invalid ngpio field\n"); + goto end; + } + + if (!of_property_read_u32(np, "st-plgpio,enb-reg", &val)) + plgpio->regs.enb = val; + else + plgpio->regs.enb = -1; + + if (!of_property_read_u32(np, "st-plgpio,wdata-reg", &val)) { + plgpio->regs.wdata = val; + } else { + dev_err(&pdev->dev, "DT: Invalid wdata reg\n"); + goto end; + } + + if (!of_property_read_u32(np, "st-plgpio,dir-reg", &val)) { + plgpio->regs.dir = val; + } else { + dev_err(&pdev->dev, "DT: Invalid dir reg\n"); + goto end; + } + + if (!of_property_read_u32(np, "st-plgpio,ie-reg", &val)) { + plgpio->regs.ie = val; + } else { + dev_err(&pdev->dev, "DT: Invalid ie reg\n"); + goto end; + } + + if (!of_property_read_u32(np, "st-plgpio,rdata-reg", &val)) { + plgpio->regs.rdata = val; + } else { + dev_err(&pdev->dev, "DT: Invalid rdata reg\n"); + goto end; + } + + if (!of_property_read_u32(np, "st-plgpio,mis-reg", &val)) { + plgpio->regs.mis = val; + } else { + dev_err(&pdev->dev, "DT: Invalid mis reg\n"); + goto end; + } + + if (!of_property_read_u32(np, "st-plgpio,eit-reg", &val)) + plgpio->regs.eit = val; + else + plgpio->regs.eit = -1; + + return 0; + +end: + return ret; +} +static int plgpio_probe(struct platform_device *pdev) +{ + struct plgpio *plgpio; + struct resource *res; + int ret, irq; + + plgpio = devm_kzalloc(&pdev->dev, sizeof(*plgpio), GFP_KERNEL); + if (!plgpio) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + plgpio->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(plgpio->base)) + return PTR_ERR(plgpio->base); + + ret = plgpio_probe_dt(pdev, plgpio); + if (ret) { + dev_err(&pdev->dev, "DT probe failed\n"); + return ret; + } + + plgpio->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(plgpio->clk)) + dev_warn(&pdev->dev, "clk_get() failed, work without it\n"); + +#ifdef CONFIG_PM_SLEEP + plgpio->csave_regs = devm_kcalloc(&pdev->dev, + DIV_ROUND_UP(plgpio->chip.ngpio, MAX_GPIO_PER_REG), + sizeof(*plgpio->csave_regs), + GFP_KERNEL); + if (!plgpio->csave_regs) + return -ENOMEM; +#endif + + platform_set_drvdata(pdev, plgpio); + spin_lock_init(&plgpio->lock); + + plgpio->chip.base = -1; + plgpio->chip.request = plgpio_request; + plgpio->chip.free = plgpio_free; + plgpio->chip.direction_input = plgpio_direction_input; + plgpio->chip.direction_output = plgpio_direction_output; + plgpio->chip.get = plgpio_get_value; + plgpio->chip.set = plgpio_set_value; + plgpio->chip.label = dev_name(&pdev->dev); + plgpio->chip.parent = &pdev->dev; + plgpio->chip.owner = THIS_MODULE; + plgpio->chip.of_node = pdev->dev.of_node; + + if (!IS_ERR(plgpio->clk)) { + ret = clk_prepare(plgpio->clk); + if (ret) { + dev_err(&pdev->dev, "clk prepare failed\n"); + return ret; + } + } + + ret = gpiochip_add_data(&plgpio->chip, plgpio); + if (ret) { + dev_err(&pdev->dev, "unable to add gpio chip\n"); + goto unprepare_clk; + } + + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + dev_info(&pdev->dev, "PLGPIO registered without IRQs\n"); + return 0; + } + + ret = gpiochip_irqchip_add(&plgpio->chip, + &plgpio_irqchip, + 0, + handle_simple_irq, + IRQ_TYPE_NONE); + if (ret) { + dev_err(&pdev->dev, "failed to add irqchip to gpiochip\n"); + goto remove_gpiochip; + } + + gpiochip_set_chained_irqchip(&plgpio->chip, + &plgpio_irqchip, + irq, + plgpio_irq_handler); + + dev_info(&pdev->dev, "PLGPIO registered with IRQs\n"); + + return 0; + +remove_gpiochip: + dev_info(&pdev->dev, "Remove gpiochip\n"); + gpiochip_remove(&plgpio->chip); +unprepare_clk: + if (!IS_ERR(plgpio->clk)) + clk_unprepare(plgpio->clk); + + return ret; +} + +#ifdef CONFIG_PM_SLEEP +static int plgpio_suspend(struct device *dev) +{ + struct plgpio *plgpio = dev_get_drvdata(dev); + int i, reg_count = DIV_ROUND_UP(plgpio->chip.ngpio, MAX_GPIO_PER_REG); + void __iomem *off; + + for (i = 0; i < reg_count; i++) { + off = plgpio->base + i * sizeof(int *); + + if (plgpio->regs.enb != -1) + plgpio->csave_regs[i].enb = + readl_relaxed(plgpio->regs.enb + off); + if (plgpio->regs.eit != -1) + plgpio->csave_regs[i].eit = + readl_relaxed(plgpio->regs.eit + off); + plgpio->csave_regs[i].wdata = readl_relaxed(plgpio->regs.wdata + + off); + plgpio->csave_regs[i].dir = readl_relaxed(plgpio->regs.dir + + off); + plgpio->csave_regs[i].ie = readl_relaxed(plgpio->regs.ie + off); + } + + return 0; +} + +/* + * This is used to correct the values in end registers. End registers contain + * extra bits that might be used for other purpose in platform. So, we shouldn't + * overwrite these bits. This macro, reads given register again, preserves other + * bit values (non-plgpio bits), and retain captured value (plgpio bits). + */ +#define plgpio_prepare_reg(__reg, _off, _mask, _tmp) \ +{ \ + _tmp = readl_relaxed(plgpio->regs.__reg + _off); \ + _tmp &= ~_mask; \ + plgpio->csave_regs[i].__reg = \ + _tmp | (plgpio->csave_regs[i].__reg & _mask); \ +} + +static int plgpio_resume(struct device *dev) +{ + struct plgpio *plgpio = dev_get_drvdata(dev); + int i, reg_count = DIV_ROUND_UP(plgpio->chip.ngpio, MAX_GPIO_PER_REG); + void __iomem *off; + u32 mask, tmp; + + for (i = 0; i < reg_count; i++) { + off = plgpio->base + i * sizeof(int *); + + if (i == reg_count - 1) { + mask = (1 << (plgpio->chip.ngpio - i * + MAX_GPIO_PER_REG)) - 1; + + if (plgpio->regs.enb != -1) + plgpio_prepare_reg(enb, off, mask, tmp); + + if (plgpio->regs.eit != -1) + plgpio_prepare_reg(eit, off, mask, tmp); + + plgpio_prepare_reg(wdata, off, mask, tmp); + plgpio_prepare_reg(dir, off, mask, tmp); + plgpio_prepare_reg(ie, off, mask, tmp); + } + + writel_relaxed(plgpio->csave_regs[i].wdata, plgpio->regs.wdata + + off); + writel_relaxed(plgpio->csave_regs[i].dir, plgpio->regs.dir + + off); + + if (plgpio->regs.eit != -1) + writel_relaxed(plgpio->csave_regs[i].eit, + plgpio->regs.eit + off); + + writel_relaxed(plgpio->csave_regs[i].ie, plgpio->regs.ie + off); + + if (plgpio->regs.enb != -1) + writel_relaxed(plgpio->csave_regs[i].enb, + plgpio->regs.enb + off); + } + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(plgpio_dev_pm_ops, plgpio_suspend, plgpio_resume); + +static const struct of_device_id plgpio_of_match[] = { + { .compatible = "st,spear-plgpio" }, + {} +}; + +static struct platform_driver plgpio_driver = { + .probe = plgpio_probe, + .driver = { + .name = "spear-plgpio", + .pm = &plgpio_dev_pm_ops, + .of_match_table = plgpio_of_match, + }, +}; + +static int __init plgpio_init(void) +{ + return platform_driver_register(&plgpio_driver); +} +subsys_initcall(plgpio_init); |