diff options
Diffstat (limited to 'drivers/gpio/gpio-davinci.c')
| -rw-r--r-- | drivers/gpio/gpio-davinci.c | 729 |
1 files changed, 729 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-davinci.c b/drivers/gpio/gpio-davinci.c new file mode 100644 index 000000000..69f3d864f --- /dev/null +++ b/drivers/gpio/gpio-davinci.c @@ -0,0 +1,729 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * TI DaVinci GPIO Support + * + * Copyright (c) 2006-2007 David Brownell + * Copyright (c) 2007, MontaVista Software, Inc. <source@mvista.com> + */ + +#include <linux/gpio/driver.h> +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/irqdomain.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/pinctrl/consumer.h> +#include <linux/platform_device.h> +#include <linux/platform_data/gpio-davinci.h> +#include <linux/irqchip/chained_irq.h> +#include <linux/spinlock.h> +#include <linux/pm_runtime.h> + +#include <asm-generic/gpio.h> + +#define MAX_REGS_BANKS 5 +#define MAX_INT_PER_BANK 32 + +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; +}; + +typedef struct irq_chip *(*gpio_get_irq_chip_cb_t)(unsigned int irq); + +#define BINTEN 0x8 /* GPIO Interrupt Per-Bank Enable Register */ + +static void __iomem *gpio_base; +static unsigned int offset_array[5] = {0x10, 0x38, 0x60, 0x88, 0xb0}; + +struct davinci_gpio_irq_data { + void __iomem *regs; + struct davinci_gpio_controller *chip; + int bank_num; +}; + +struct davinci_gpio_controller { + struct gpio_chip chip; + struct irq_domain *irq_domain; + /* Serialize access to GPIO registers */ + spinlock_t lock; + void __iomem *regs[MAX_REGS_BANKS]; + int gpio_unbanked; + int irqs[MAX_INT_PER_BANK]; + struct davinci_gpio_regs context[MAX_REGS_BANKS]; + u32 binten_context; +}; + +static inline u32 __gpio_mask(unsigned gpio) +{ + return 1 << (gpio % 32); +} + +static inline struct davinci_gpio_regs __iomem *irq2regs(struct irq_data *d) +{ + struct davinci_gpio_regs __iomem *g; + + g = (__force struct davinci_gpio_regs __iomem *)irq_data_get_irq_chip_data(d); + + return g; +} + +static int davinci_gpio_irq_setup(struct platform_device *pdev); + +/*--------------------------------------------------------------------------*/ + +/* 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 = gpiochip_get_data(chip); + struct davinci_gpio_regs __iomem *g; + unsigned long flags; + u32 temp; + int bank = offset / 32; + u32 mask = __gpio_mask(offset); + + g = d->regs[bank]; + spin_lock_irqsave(&d->lock, flags); + temp = readl_relaxed(&g->dir); + if (out) { + temp &= ~mask; + writel_relaxed(mask, value ? &g->set_data : &g->clr_data); + } else { + temp |= mask; + } + writel_relaxed(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 = gpiochip_get_data(chip); + struct davinci_gpio_regs __iomem *g; + int bank = offset / 32; + + g = d->regs[bank]; + + return !!(__gpio_mask(offset) & readl_relaxed(&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 = gpiochip_get_data(chip); + struct davinci_gpio_regs __iomem *g; + int bank = offset / 32; + + g = d->regs[bank]; + + writel_relaxed(__gpio_mask(offset), + value ? &g->set_data : &g->clr_data); +} + +static struct davinci_gpio_platform_data * +davinci_gpio_get_pdata(struct platform_device *pdev) +{ + struct device_node *dn = pdev->dev.of_node; + struct davinci_gpio_platform_data *pdata; + int ret; + u32 val; + + if (!IS_ENABLED(CONFIG_OF) || !pdev->dev.of_node) + return dev_get_platdata(&pdev->dev); + + pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); + if (!pdata) + return NULL; + + ret = of_property_read_u32(dn, "ti,ngpio", &val); + if (ret) + goto of_err; + + pdata->ngpio = val; + + ret = of_property_read_u32(dn, "ti,davinci-gpio-unbanked", &val); + if (ret) + goto of_err; + + pdata->gpio_unbanked = val; + + return pdata; + +of_err: + dev_err(&pdev->dev, "Populating pdata from DT failed: err %d\n", ret); + return NULL; +} + +static int davinci_gpio_probe(struct platform_device *pdev) +{ + int bank, i, ret = 0; + unsigned int ngpio, nbank, nirq; + struct davinci_gpio_controller *chips; + struct davinci_gpio_platform_data *pdata; + struct device *dev = &pdev->dev; + + pdata = davinci_gpio_get_pdata(pdev); + if (!pdata) { + dev_err(dev, "No platform data found\n"); + return -EINVAL; + } + + dev->platform_data = pdata; + + /* + * The gpio banks conceptually expose a segmented bitmap, + * and "ngpio" is one more than the largest zero-based + * bit index that's valid. + */ + ngpio = pdata->ngpio; + if (ngpio == 0) { + dev_err(dev, "How many GPIOs?\n"); + return -EINVAL; + } + + if (WARN_ON(ARCH_NR_GPIOS < ngpio)) + ngpio = ARCH_NR_GPIOS; + + /* + * If there are unbanked interrupts then the number of + * interrupts is equal to number of gpios else all are banked so + * number of interrupts is equal to number of banks(each with 16 gpios) + */ + if (pdata->gpio_unbanked) + nirq = pdata->gpio_unbanked; + else + nirq = DIV_ROUND_UP(ngpio, 16); + + chips = devm_kzalloc(dev, sizeof(*chips), GFP_KERNEL); + if (!chips) + return -ENOMEM; + + gpio_base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(gpio_base)) + return PTR_ERR(gpio_base); + + for (i = 0; i < nirq; i++) { + chips->irqs[i] = platform_get_irq(pdev, i); + if (chips->irqs[i] < 0) + return dev_err_probe(dev, chips->irqs[i], "IRQ not populated\n"); + } + + chips->chip.label = dev_name(dev); + + chips->chip.direction_input = davinci_direction_in; + chips->chip.get = davinci_gpio_get; + chips->chip.direction_output = davinci_direction_out; + chips->chip.set = davinci_gpio_set; + + chips->chip.ngpio = ngpio; + chips->chip.base = pdata->no_auto_base ? pdata->base : -1; + +#ifdef CONFIG_OF_GPIO + chips->chip.of_gpio_n_cells = 2; + chips->chip.parent = dev; + chips->chip.request = gpiochip_generic_request; + chips->chip.free = gpiochip_generic_free; +#endif + spin_lock_init(&chips->lock); + + nbank = DIV_ROUND_UP(ngpio, 32); + for (bank = 0; bank < nbank; bank++) + chips->regs[bank] = gpio_base + offset_array[bank]; + + ret = devm_gpiochip_add_data(dev, &chips->chip, chips); + if (ret) + return ret; + + platform_set_drvdata(pdev, chips); + ret = davinci_gpio_irq_setup(pdev); + if (ret) + return ret; + + return 0; +} + +/*--------------------------------------------------------------------------*/ +/* + * 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); + uintptr_t mask = (uintptr_t)irq_data_get_irq_handler_data(d); + + writel_relaxed(mask, &g->clr_falling); + writel_relaxed(mask, &g->clr_rising); +} + +static void gpio_irq_enable(struct irq_data *d) +{ + struct davinci_gpio_regs __iomem *g = irq2regs(d); + uintptr_t mask = (uintptr_t)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) + writel_relaxed(mask, &g->set_falling); + if (status & IRQ_TYPE_EDGE_RISING) + writel_relaxed(mask, &g->set_rising); +} + +static int gpio_irq_type(struct irq_data *d, unsigned trigger) +{ + 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 | IRQCHIP_SKIP_SET_WAKE, +}; + +static void gpio_irq_handler(struct irq_desc *desc) +{ + struct davinci_gpio_regs __iomem *g; + u32 mask = 0xffff; + int bank_num; + struct davinci_gpio_controller *d; + struct davinci_gpio_irq_data *irqdata; + + irqdata = (struct davinci_gpio_irq_data *)irq_desc_get_handler_data(desc); + bank_num = irqdata->bank_num; + g = irqdata->regs; + d = irqdata->chip; + + /* we only care about one bank */ + if ((bank_num % 2) == 1) + mask <<= 16; + + /* temporarily mask (level sensitive) parent IRQ */ + chained_irq_enter(irq_desc_get_chip(desc), desc); + while (1) { + u32 status; + int bit; + irq_hw_number_t hw_irq; + + /* ack any irqs */ + status = readl_relaxed(&g->intstat) & mask; + if (!status) + break; + writel_relaxed(status, &g->intstat); + + /* now demux them to the right lowlevel handler */ + + while (status) { + bit = __ffs(status); + status &= ~BIT(bit); + /* Max number of gpios per controller is 144 so + * hw_irq will be in [0..143] + */ + hw_irq = (bank_num / 2) * 32 + bit; + + generic_handle_domain_irq(d->irq_domain, hw_irq); + } + } + chained_irq_exit(irq_desc_get_chip(desc), desc); + /* now it may re-trigger */ +} + +static int gpio_to_irq_banked(struct gpio_chip *chip, unsigned offset) +{ + struct davinci_gpio_controller *d = gpiochip_get_data(chip); + + if (d->irq_domain) + return irq_create_mapping(d->irq_domain, offset); + else + return -ENXIO; +} + +static int gpio_to_irq_unbanked(struct gpio_chip *chip, unsigned offset) +{ + struct davinci_gpio_controller *d = gpiochip_get_data(chip); + + /* + * 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 < d->gpio_unbanked) + return d->irqs[offset]; + else + return -ENODEV; +} + +static int gpio_irq_type_unbanked(struct irq_data *data, unsigned trigger) +{ + struct davinci_gpio_controller *d; + struct davinci_gpio_regs __iomem *g; + u32 mask, i; + + d = (struct davinci_gpio_controller *)irq_data_get_irq_handler_data(data); + g = (struct davinci_gpio_regs __iomem *)d->regs[0]; + for (i = 0; i < MAX_INT_PER_BANK; i++) + if (data->irq == d->irqs[i]) + break; + + if (i == MAX_INT_PER_BANK) + return -EINVAL; + + mask = __gpio_mask(i); + + if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING)) + return -EINVAL; + + writel_relaxed(mask, (trigger & IRQ_TYPE_EDGE_FALLING) + ? &g->set_falling : &g->clr_falling); + writel_relaxed(mask, (trigger & IRQ_TYPE_EDGE_RISING) + ? &g->set_rising : &g->clr_rising); + + return 0; +} + +static int +davinci_gpio_irq_map(struct irq_domain *d, unsigned int irq, + irq_hw_number_t hw) +{ + struct davinci_gpio_controller *chips = + (struct davinci_gpio_controller *)d->host_data; + struct davinci_gpio_regs __iomem *g = chips->regs[hw / 32]; + + irq_set_chip_and_handler_name(irq, &gpio_irqchip, handle_simple_irq, + "davinci_gpio"); + irq_set_irq_type(irq, IRQ_TYPE_NONE); + irq_set_chip_data(irq, (__force void *)g); + irq_set_handler_data(irq, (void *)(uintptr_t)__gpio_mask(hw)); + + return 0; +} + +static const struct irq_domain_ops davinci_gpio_irq_ops = { + .map = davinci_gpio_irq_map, + .xlate = irq_domain_xlate_onetwocell, +}; + +static struct irq_chip *davinci_gpio_get_irq_chip(unsigned int irq) +{ + static struct irq_chip_type gpio_unbanked; + + gpio_unbanked = *irq_data_get_chip_type(irq_get_irq_data(irq)); + + return &gpio_unbanked.chip; +}; + +static struct irq_chip *keystone_gpio_get_irq_chip(unsigned int irq) +{ + static struct irq_chip gpio_unbanked; + + gpio_unbanked = *irq_get_chip(irq); + return &gpio_unbanked; +}; + +static const struct of_device_id davinci_gpio_ids[]; + +/* + * 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 davinci_gpio_irq_setup(struct platform_device *pdev) +{ + unsigned gpio, bank; + int irq; + int ret; + struct clk *clk; + u32 binten = 0; + unsigned ngpio; + struct device *dev = &pdev->dev; + struct davinci_gpio_controller *chips = platform_get_drvdata(pdev); + struct davinci_gpio_platform_data *pdata = dev->platform_data; + struct davinci_gpio_regs __iomem *g; + struct irq_domain *irq_domain = NULL; + const struct of_device_id *match; + struct irq_chip *irq_chip; + struct davinci_gpio_irq_data *irqdata; + gpio_get_irq_chip_cb_t gpio_get_irq_chip; + + /* + * Use davinci_gpio_get_irq_chip by default to handle non DT cases + */ + gpio_get_irq_chip = davinci_gpio_get_irq_chip; + match = of_match_device(of_match_ptr(davinci_gpio_ids), + dev); + if (match) + gpio_get_irq_chip = (gpio_get_irq_chip_cb_t)match->data; + + ngpio = pdata->ngpio; + + clk = devm_clk_get(dev, "gpio"); + if (IS_ERR(clk)) { + dev_err(dev, "Error %ld getting gpio clock\n", PTR_ERR(clk)); + return PTR_ERR(clk); + } + + ret = clk_prepare_enable(clk); + if (ret) + return ret; + + if (!pdata->gpio_unbanked) { + irq = devm_irq_alloc_descs(dev, -1, 0, ngpio, 0); + if (irq < 0) { + dev_err(dev, "Couldn't allocate IRQ numbers\n"); + clk_disable_unprepare(clk); + return irq; + } + + irq_domain = irq_domain_add_legacy(dev->of_node, ngpio, irq, 0, + &davinci_gpio_irq_ops, + chips); + if (!irq_domain) { + dev_err(dev, "Couldn't register an IRQ domain\n"); + clk_disable_unprepare(clk); + return -ENODEV; + } + } + + /* + * 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. + */ + chips->chip.to_irq = gpio_to_irq_banked; + chips->irq_domain = irq_domain; + + /* + * 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 (pdata->gpio_unbanked) { + /* pass "bank 0" GPIO IRQs to AINTC */ + chips->chip.to_irq = gpio_to_irq_unbanked; + chips->gpio_unbanked = pdata->gpio_unbanked; + binten = GENMASK(pdata->gpio_unbanked / 16, 0); + + /* AINTC handles mask/unmask; GPIO handles triggering */ + irq = chips->irqs[0]; + irq_chip = gpio_get_irq_chip(irq); + irq_chip->name = "GPIO-AINTC"; + irq_chip->irq_set_type = gpio_irq_type_unbanked; + + /* default trigger: both edges */ + g = chips->regs[0]; + writel_relaxed(~0, &g->set_falling); + writel_relaxed(~0, &g->set_rising); + + /* set the direct IRQs up to use that irqchip */ + for (gpio = 0; gpio < pdata->gpio_unbanked; gpio++) { + irq_set_chip(chips->irqs[gpio], irq_chip); + irq_set_handler_data(chips->irqs[gpio], chips); + irq_set_status_flags(chips->irqs[gpio], + 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, bank = 0; gpio < ngpio; bank++, gpio += 16) { + /* disabled by default, enabled only as needed + * There are register sets for 32 GPIOs. 2 banks of 16 + * GPIOs are covered by each set of registers hence divide by 2 + */ + g = chips->regs[bank / 2]; + writel_relaxed(~0, &g->clr_falling); + writel_relaxed(~0, &g->clr_rising); + + /* + * 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. + */ + irqdata = devm_kzalloc(&pdev->dev, + sizeof(struct + davinci_gpio_irq_data), + GFP_KERNEL); + if (!irqdata) { + clk_disable_unprepare(clk); + return -ENOMEM; + } + + irqdata->regs = g; + irqdata->bank_num = bank; + irqdata->chip = chips; + + irq_set_chained_handler_and_data(chips->irqs[bank], + gpio_irq_handler, irqdata); + + binten |= BIT(bank); + } + +done: + /* + * BINTEN -- per-bank interrupt enable. genirq would also let these + * bits be set/cleared dynamically. + */ + writel_relaxed(binten, gpio_base + BINTEN); + + return 0; +} + +static void davinci_gpio_save_context(struct davinci_gpio_controller *chips, + u32 nbank) +{ + struct davinci_gpio_regs __iomem *g; + struct davinci_gpio_regs *context; + u32 bank; + void __iomem *base; + + base = chips->regs[0] - offset_array[0]; + chips->binten_context = readl_relaxed(base + BINTEN); + + for (bank = 0; bank < nbank; bank++) { + g = chips->regs[bank]; + context = &chips->context[bank]; + context->dir = readl_relaxed(&g->dir); + context->set_data = readl_relaxed(&g->set_data); + context->set_rising = readl_relaxed(&g->set_rising); + context->set_falling = readl_relaxed(&g->set_falling); + } + + /* Clear all interrupt status registers */ + writel_relaxed(GENMASK(31, 0), &g->intstat); +} + +static void davinci_gpio_restore_context(struct davinci_gpio_controller *chips, + u32 nbank) +{ + struct davinci_gpio_regs __iomem *g; + struct davinci_gpio_regs *context; + u32 bank; + void __iomem *base; + + base = chips->regs[0] - offset_array[0]; + + if (readl_relaxed(base + BINTEN) != chips->binten_context) + writel_relaxed(chips->binten_context, base + BINTEN); + + for (bank = 0; bank < nbank; bank++) { + g = chips->regs[bank]; + context = &chips->context[bank]; + if (readl_relaxed(&g->dir) != context->dir) + writel_relaxed(context->dir, &g->dir); + if (readl_relaxed(&g->set_data) != context->set_data) + writel_relaxed(context->set_data, &g->set_data); + if (readl_relaxed(&g->set_rising) != context->set_rising) + writel_relaxed(context->set_rising, &g->set_rising); + if (readl_relaxed(&g->set_falling) != context->set_falling) + writel_relaxed(context->set_falling, &g->set_falling); + } +} + +static int davinci_gpio_suspend(struct device *dev) +{ + struct davinci_gpio_controller *chips = dev_get_drvdata(dev); + struct davinci_gpio_platform_data *pdata = dev_get_platdata(dev); + u32 nbank = DIV_ROUND_UP(pdata->ngpio, 32); + + davinci_gpio_save_context(chips, nbank); + + return 0; +} + +static int davinci_gpio_resume(struct device *dev) +{ + struct davinci_gpio_controller *chips = dev_get_drvdata(dev); + struct davinci_gpio_platform_data *pdata = dev_get_platdata(dev); + u32 nbank = DIV_ROUND_UP(pdata->ngpio, 32); + + davinci_gpio_restore_context(chips, nbank); + + return 0; +} + +DEFINE_SIMPLE_DEV_PM_OPS(davinci_gpio_dev_pm_ops, davinci_gpio_suspend, + davinci_gpio_resume); + +static const struct of_device_id davinci_gpio_ids[] = { + { .compatible = "ti,keystone-gpio", keystone_gpio_get_irq_chip}, + { .compatible = "ti,am654-gpio", keystone_gpio_get_irq_chip}, + { .compatible = "ti,dm6441-gpio", davinci_gpio_get_irq_chip}, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(of, davinci_gpio_ids); + +static struct platform_driver davinci_gpio_driver = { + .probe = davinci_gpio_probe, + .driver = { + .name = "davinci_gpio", + .pm = pm_sleep_ptr(&davinci_gpio_dev_pm_ops), + .of_match_table = of_match_ptr(davinci_gpio_ids), + }, +}; + +/** + * GPIO driver registration needs to be done before machine_init functions + * access GPIO. Hence davinci_gpio_drv_reg() is a postcore_initcall. + */ +static int __init davinci_gpio_drv_reg(void) +{ + return platform_driver_register(&davinci_gpio_driver); +} +postcore_initcall(davinci_gpio_drv_reg); |