diff options
Diffstat (limited to 'drivers/gpio/gpio-davinci.c')
| -rw-r--r-- | drivers/gpio/gpio-davinci.c | 458 |
1 files changed, 458 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-davinci.c b/drivers/gpio/gpio-davinci.c new file mode 100644 index 00000000000..a8066e8edad --- /dev/null +++ b/drivers/gpio/gpio-davinci.c @@ -0,0 +1,458 @@ +/* + * TI DaVinci GPIO Support + * + * Copyright (c) 2006-2007 David Brownell + * Copyright (c) 2007, MontaVista Software, Inc. <source@mvista.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ +#include <linux/gpio.h> +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/io.h> + +#include <asm/mach/irq.h> + +struct davinci_gpio_regs { + u32 dir; + u32 out_data; + u32 set_data; + u32 clr_data; + u32 in_data; + u32 set_rising; + u32 clr_rising; + u32 set_falling; + u32 clr_falling; + u32 intstat; +}; + +#define chip2controller(chip) \ + container_of(chip, struct davinci_gpio_controller, chip) + +static struct davinci_gpio_controller chips[DIV_ROUND_UP(DAVINCI_N_GPIO, 32)]; +static void __iomem *gpio_base; + +static struct davinci_gpio_regs __iomem __init *gpio2regs(unsigned gpio) +{ + void __iomem *ptr; + + if (gpio < 32 * 1) + ptr = gpio_base + 0x10; + else if (gpio < 32 * 2) + ptr = gpio_base + 0x38; + else if (gpio < 32 * 3) + ptr = gpio_base + 0x60; + else if (gpio < 32 * 4) + ptr = gpio_base + 0x88; + else if (gpio < 32 * 5) + ptr = gpio_base + 0xb0; + else + ptr = NULL; + return ptr; +} + +static inline struct davinci_gpio_regs __iomem *irq2regs(int irq) +{ + struct davinci_gpio_regs __iomem *g; + + g = (__force struct davinci_gpio_regs __iomem *)irq_get_chip_data(irq); + + return g; +} + +static int __init davinci_gpio_irq_setup(void); + +/*--------------------------------------------------------------------------*/ + +/* board setup code *MUST* setup pinmux and enable the GPIO clock. */ +static inline int __davinci_direction(struct gpio_chip *chip, + unsigned offset, bool out, int value) +{ + struct davinci_gpio_controller *d = chip2controller(chip); + struct davinci_gpio_regs __iomem *g = d->regs; + unsigned long flags; + u32 temp; + u32 mask = 1 << offset; + + spin_lock_irqsave(&d->lock, flags); + temp = __raw_readl(&g->dir); + if (out) { + temp &= ~mask; + __raw_writel(mask, value ? &g->set_data : &g->clr_data); + } else { + temp |= mask; + } + __raw_writel(temp, &g->dir); + spin_unlock_irqrestore(&d->lock, flags); + + return 0; +} + +static int davinci_direction_in(struct gpio_chip *chip, unsigned offset) +{ + return __davinci_direction(chip, offset, false, 0); +} + +static int +davinci_direction_out(struct gpio_chip *chip, unsigned offset, int value) +{ + return __davinci_direction(chip, offset, true, value); +} + +/* + * Read the pin's value (works even if it's set up as output); + * returns zero/nonzero. + * + * Note that changes are synched to the GPIO clock, so reading values back + * right after you've set them may give old values. + */ +static int davinci_gpio_get(struct gpio_chip *chip, unsigned offset) +{ + struct davinci_gpio_controller *d = chip2controller(chip); + struct davinci_gpio_regs __iomem *g = d->regs; + + return (1 << offset) & __raw_readl(&g->in_data); +} + +/* + * Assuming the pin is muxed as a gpio output, set its output value. + */ +static void +davinci_gpio_set(struct gpio_chip *chip, unsigned offset, int value) +{ + struct davinci_gpio_controller *d = chip2controller(chip); + struct davinci_gpio_regs __iomem *g = d->regs; + + __raw_writel((1 << offset), value ? &g->set_data : &g->clr_data); +} + +static int __init davinci_gpio_setup(void) +{ + int i, base; + unsigned ngpio; + struct davinci_soc_info *soc_info = &davinci_soc_info; + struct davinci_gpio_regs *regs; + + if (soc_info->gpio_type != GPIO_TYPE_DAVINCI) + return 0; + + /* + * The gpio banks conceptually expose a segmented bitmap, + * and "ngpio" is one more than the largest zero-based + * bit index that's valid. + */ + ngpio = soc_info->gpio_num; + if (ngpio == 0) { + pr_err("GPIO setup: how many GPIOs?\n"); + return -EINVAL; + } + + if (WARN_ON(DAVINCI_N_GPIO < ngpio)) + ngpio = DAVINCI_N_GPIO; + + gpio_base = ioremap(soc_info->gpio_base, SZ_4K); + if (WARN_ON(!gpio_base)) + return -ENOMEM; + + for (i = 0, base = 0; base < ngpio; i++, base += 32) { + chips[i].chip.label = "DaVinci"; + + chips[i].chip.direction_input = davinci_direction_in; + chips[i].chip.get = davinci_gpio_get; + chips[i].chip.direction_output = davinci_direction_out; + chips[i].chip.set = davinci_gpio_set; + + chips[i].chip.base = base; + chips[i].chip.ngpio = ngpio - base; + if (chips[i].chip.ngpio > 32) + chips[i].chip.ngpio = 32; + + spin_lock_init(&chips[i].lock); + + regs = gpio2regs(base); + chips[i].regs = regs; + chips[i].set_data = ®s->set_data; + chips[i].clr_data = ®s->clr_data; + chips[i].in_data = ®s->in_data; + + gpiochip_add(&chips[i].chip); + } + + soc_info->gpio_ctlrs = chips; + soc_info->gpio_ctlrs_num = DIV_ROUND_UP(ngpio, 32); + + davinci_gpio_irq_setup(); + return 0; +} +pure_initcall(davinci_gpio_setup); + +/*--------------------------------------------------------------------------*/ +/* + * We expect irqs will normally be set up as input pins, but they can also be + * used as output pins ... which is convenient for testing. + * + * NOTE: The first few GPIOs also have direct INTC hookups in addition + * to their GPIOBNK0 irq, with a bit less overhead. + * + * All those INTC hookups (direct, plus several IRQ banks) can also + * serve as EDMA event triggers. + */ + +static void gpio_irq_disable(struct irq_data *d) +{ + struct davinci_gpio_regs __iomem *g = irq2regs(d->irq); + u32 mask = (u32) irq_data_get_irq_handler_data(d); + + __raw_writel(mask, &g->clr_falling); + __raw_writel(mask, &g->clr_rising); +} + +static void gpio_irq_enable(struct irq_data *d) +{ + struct davinci_gpio_regs __iomem *g = irq2regs(d->irq); + u32 mask = (u32) irq_data_get_irq_handler_data(d); + unsigned status = irqd_get_trigger_type(d); + + status &= IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING; + if (!status) + status = IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING; + + if (status & IRQ_TYPE_EDGE_FALLING) + __raw_writel(mask, &g->set_falling); + if (status & IRQ_TYPE_EDGE_RISING) + __raw_writel(mask, &g->set_rising); +} + +static int gpio_irq_type(struct irq_data *d, unsigned trigger) +{ + struct davinci_gpio_regs __iomem *g = irq2regs(d->irq); + u32 mask = (u32) irq_data_get_irq_handler_data(d); + + if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING)) + return -EINVAL; + + return 0; +} + +static struct irq_chip gpio_irqchip = { + .name = "GPIO", + .irq_enable = gpio_irq_enable, + .irq_disable = gpio_irq_disable, + .irq_set_type = gpio_irq_type, + .flags = IRQCHIP_SET_TYPE_MASKED, +}; + +static void +gpio_irq_handler(unsigned irq, struct irq_desc *desc) +{ + struct davinci_gpio_regs __iomem *g; + u32 mask = 0xffff; + struct davinci_gpio_controller *d; + + d = (struct davinci_gpio_controller *)irq_desc_get_handler_data(desc); + g = (struct davinci_gpio_regs __iomem *)d->regs; + + /* we only care about one bank */ + if (irq & 1) + mask <<= 16; + + /* temporarily mask (level sensitive) parent IRQ */ + desc->irq_data.chip->irq_mask(&desc->irq_data); + desc->irq_data.chip->irq_ack(&desc->irq_data); + while (1) { + u32 status; + int n; + int res; + + /* ack any irqs */ + status = __raw_readl(&g->intstat) & mask; + if (!status) + break; + __raw_writel(status, &g->intstat); + + /* now demux them to the right lowlevel handler */ + n = d->irq_base; + if (irq & 1) { + n += 16; + status >>= 16; + } + + while (status) { + res = ffs(status); + n += res; + generic_handle_irq(n - 1); + status >>= res; + } + } + desc->irq_data.chip->irq_unmask(&desc->irq_data); + /* now it may re-trigger */ +} + +static int gpio_to_irq_banked(struct gpio_chip *chip, unsigned offset) +{ + struct davinci_gpio_controller *d = chip2controller(chip); + + if (d->irq_base >= 0) + return d->irq_base + offset; + else + return -ENODEV; +} + +static int gpio_to_irq_unbanked(struct gpio_chip *chip, unsigned offset) +{ + struct davinci_soc_info *soc_info = &davinci_soc_info; + + /* NOTE: we assume for now that only irqs in the first gpio_chip + * can provide direct-mapped IRQs to AINTC (up to 32 GPIOs). + */ + if (offset < soc_info->gpio_unbanked) + return soc_info->gpio_irq + offset; + else + return -ENODEV; +} + +static int gpio_irq_type_unbanked(struct irq_data *d, unsigned trigger) +{ + struct davinci_gpio_regs __iomem *g = irq2regs(d->irq); + u32 mask = (u32) irq_data_get_irq_handler_data(d); + + if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING)) + return -EINVAL; + + __raw_writel(mask, (trigger & IRQ_TYPE_EDGE_FALLING) + ? &g->set_falling : &g->clr_falling); + __raw_writel(mask, (trigger & IRQ_TYPE_EDGE_RISING) + ? &g->set_rising : &g->clr_rising); + + return 0; +} + +/* + * NOTE: for suspend/resume, probably best to make a platform_device with + * suspend_late/resume_resume calls hooking into results of the set_wake() + * calls ... so if no gpios are wakeup events the clock can be disabled, + * with outputs left at previously set levels, and so that VDD3P3V.IOPWDN0 + * (dm6446) can be set appropriately for GPIOV33 pins. + */ + +static int __init davinci_gpio_irq_setup(void) +{ + unsigned gpio, irq, bank; + struct clk *clk; + u32 binten = 0; + unsigned ngpio, bank_irq; + struct davinci_soc_info *soc_info = &davinci_soc_info; + struct davinci_gpio_regs __iomem *g; + + ngpio = soc_info->gpio_num; + + bank_irq = soc_info->gpio_irq; + if (bank_irq == 0) { + printk(KERN_ERR "Don't know first GPIO bank IRQ.\n"); + return -EINVAL; + } + + clk = clk_get(NULL, "gpio"); + if (IS_ERR(clk)) { + printk(KERN_ERR "Error %ld getting gpio clock?\n", + PTR_ERR(clk)); + return PTR_ERR(clk); + } + clk_enable(clk); + + /* Arrange gpio_to_irq() support, handling either direct IRQs or + * banked IRQs. Having GPIOs in the first GPIO bank use direct + * IRQs, while the others use banked IRQs, would need some setup + * tweaks to recognize hardware which can do that. + */ + for (gpio = 0, bank = 0; gpio < ngpio; bank++, gpio += 32) { + chips[bank].chip.to_irq = gpio_to_irq_banked; + chips[bank].irq_base = soc_info->gpio_unbanked + ? -EINVAL + : (soc_info->intc_irq_num + gpio); + } + + /* + * AINTC can handle direct/unbanked IRQs for GPIOs, with the GPIO + * controller only handling trigger modes. We currently assume no + * IRQ mux conflicts; gpio_irq_type_unbanked() is only for GPIOs. + */ + if (soc_info->gpio_unbanked) { + static struct irq_chip gpio_irqchip_unbanked; + + /* pass "bank 0" GPIO IRQs to AINTC */ + chips[0].chip.to_irq = gpio_to_irq_unbanked; + binten = BIT(0); + + /* AINTC handles mask/unmask; GPIO handles triggering */ + irq = bank_irq; + gpio_irqchip_unbanked = *irq_get_chip(irq); + gpio_irqchip_unbanked.name = "GPIO-AINTC"; + gpio_irqchip_unbanked.irq_set_type = gpio_irq_type_unbanked; + + /* default trigger: both edges */ + g = gpio2regs(0); + __raw_writel(~0, &g->set_falling); + __raw_writel(~0, &g->set_rising); + + /* set the direct IRQs up to use that irqchip */ + for (gpio = 0; gpio < soc_info->gpio_unbanked; gpio++, irq++) { + irq_set_chip(irq, &gpio_irqchip_unbanked); + irq_set_handler_data(irq, (void *)__gpio_mask(gpio)); + irq_set_chip_data(irq, (__force void *)g); + irq_set_status_flags(irq, IRQ_TYPE_EDGE_BOTH); + } + + goto done; + } + + /* + * Or, AINTC can handle IRQs for banks of 16 GPIO IRQs, which we + * then chain through our own handler. + */ + for (gpio = 0, irq = gpio_to_irq(0), bank = 0; + gpio < ngpio; + bank++, bank_irq++) { + unsigned i; + + /* disabled by default, enabled only as needed */ + g = gpio2regs(gpio); + __raw_writel(~0, &g->clr_falling); + __raw_writel(~0, &g->clr_rising); + + /* set up all irqs in this bank */ + irq_set_chained_handler(bank_irq, gpio_irq_handler); + + /* + * Each chip handles 32 gpios, and each irq bank consists of 16 + * gpio irqs. Pass the irq bank's corresponding controller to + * the chained irq handler. + */ + irq_set_handler_data(bank_irq, &chips[gpio / 32]); + + for (i = 0; i < 16 && gpio < ngpio; i++, irq++, gpio++) { + irq_set_chip(irq, &gpio_irqchip); + irq_set_chip_data(irq, (__force void *)g); + irq_set_handler_data(irq, (void *)__gpio_mask(gpio)); + irq_set_handler(irq, handle_simple_irq); + set_irq_flags(irq, IRQF_VALID); + } + + binten |= BIT(bank); + } + +done: + /* BINTEN -- per-bank interrupt enable. genirq would also let these + * bits be set/cleared dynamically. + */ + __raw_writel(binten, gpio_base + 0x08); + + printk(KERN_INFO "DaVinci: %d gpio irqs\n", irq - gpio_to_irq(0)); + + return 0; +} |