/* * 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.h> #include <linux/io.h> #include <linux/irq.h> #include <linux/irqdomain.h> #include <linux/irqchip/chained_irq.h> #include <linux/module.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 * irq_base: irq number of plgpio0 * 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; unsigned irq_base; struct irq_domain *irq_domain; 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 = container_of(chip, struct plgpio, 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 = container_of(chip, struct plgpio, 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 = container_of(chip, struct plgpio, 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 = container_of(chip, struct plgpio, 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 = container_of(chip, struct plgpio, chip); int gpio = chip->base + offset; unsigned long flags; int ret = 0; if (offset >= chip->ngpio) return -EINVAL; ret = pinctrl_request_gpio(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_free_gpio(gpio); return ret; } static void plgpio_free(struct gpio_chip *chip, unsigned offset) { struct plgpio *plgpio = container_of(chip, struct plgpio, 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_free_gpio(gpio); } static int plgpio_to_irq(struct gpio_chip *chip, unsigned offset) { struct plgpio *plgpio = container_of(chip, struct plgpio, chip); if (IS_ERR_VALUE(plgpio->irq_base)) return -EINVAL; return irq_find_mapping(plgpio->irq_domain, offset); } /* PLGPIO IRQ */ static void plgpio_irq_disable(struct irq_data *d) { struct plgpio *plgpio = irq_data_get_irq_chip_data(d); int offset = d->irq - plgpio->irq_base; 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 plgpio *plgpio = irq_data_get_irq_chip_data(d); int offset = d->irq - plgpio->irq_base; 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 plgpio *plgpio = irq_data_get_irq_chip_data(d); int offset = d->irq - plgpio->irq_base; 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(unsigned irq, struct irq_desc *desc) { struct plgpio *plgpio = irq_get_handler_data(irq); 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(plgpio_to_irq(&plgpio->chip, 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; } 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 device_node *np = pdev->dev.of_node; struct plgpio *plgpio; struct resource *res; int ret, irq, i; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) { dev_err(&pdev->dev, "invalid IORESOURCE_MEM\n"); return -EBUSY; } plgpio = devm_kzalloc(&pdev->dev, sizeof(*plgpio), GFP_KERNEL); if (!plgpio) { dev_err(&pdev->dev, "memory allocation fail\n"); return -ENOMEM; } 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_kzalloc(&pdev->dev, sizeof(*plgpio->csave_regs) * DIV_ROUND_UP(plgpio->chip.ngpio, MAX_GPIO_PER_REG), GFP_KERNEL); if (!plgpio->csave_regs) { dev_err(&pdev->dev, "csave registers memory allocation fail\n"); return -ENOMEM; } #endif platform_set_drvdata(pdev, plgpio); spin_lock_init(&plgpio->lock); plgpio->irq_base = -1; 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.to_irq = plgpio_to_irq; plgpio->chip.label = dev_name(&pdev->dev); plgpio->chip.dev = &pdev->dev; plgpio->chip.owner = THIS_MODULE; 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(&plgpio->chip); 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, "irqs not supported\n"); return 0; } plgpio->irq_base = irq_alloc_descs(-1, 0, plgpio->chip.ngpio, 0); if (IS_ERR_VALUE(plgpio->irq_base)) { /* we would not support irq for gpio */ dev_warn(&pdev->dev, "couldn't allocate irq base\n"); return 0; } plgpio->irq_domain = irq_domain_add_legacy(np, plgpio->chip.ngpio, plgpio->irq_base, 0, &irq_domain_simple_ops, NULL); if (WARN_ON(!plgpio->irq_domain)) { dev_err(&pdev->dev, "irq domain init failed\n"); irq_free_descs(plgpio->irq_base, plgpio->chip.ngpio); ret = -ENXIO; goto remove_gpiochip; } irq_set_chained_handler(irq, plgpio_irq_handler); for (i = 0; i < plgpio->chip.ngpio; i++) { irq_set_chip_and_handler(i + plgpio->irq_base, &plgpio_irqchip, handle_simple_irq); set_irq_flags(i + plgpio->irq_base, IRQF_VALID); irq_set_chip_data(i + plgpio->irq_base, plgpio); } irq_set_handler_data(irq, plgpio); dev_info(&pdev->dev, "PLGPIO registered with IRQs\n"); return 0; remove_gpiochip: dev_info(&pdev->dev, "Remove gpiochip\n"); if (gpiochip_remove(&plgpio->chip)) dev_err(&pdev->dev, "unable to remove gpiochip\n"); 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" }, {} }; MODULE_DEVICE_TABLE(of, plgpio_of_match); static struct platform_driver plgpio_driver = { .probe = plgpio_probe, .driver = { .owner = THIS_MODULE, .name = "spear-plgpio", .pm = &plgpio_dev_pm_ops, .of_match_table = of_match_ptr(plgpio_of_match), }, }; static int __init plgpio_init(void) { return platform_driver_register(&plgpio_driver); } subsys_initcall(plgpio_init); MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>"); MODULE_DESCRIPTION("ST Microlectronics SPEAr PLGPIO driver"); MODULE_LICENSE("GPL");