diff options
Diffstat (limited to 'drivers/gpio/gpio-npcm-sgpio.c')
| -rw-r--r-- | drivers/gpio/gpio-npcm-sgpio.c | 619 |
1 files changed, 619 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-npcm-sgpio.c b/drivers/gpio/gpio-npcm-sgpio.c new file mode 100644 index 000000000000..d31788b43abc --- /dev/null +++ b/drivers/gpio/gpio-npcm-sgpio.c @@ -0,0 +1,619 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Nuvoton NPCM Serial GPIO Driver + * + * Copyright (C) 2021 Nuvoton Technologies + */ + +#include <linux/bitfield.h> +#include <linux/clk.h> +#include <linux/gpio/driver.h> +#include <linux/hashtable.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/spinlock.h> +#include <linux/string.h> +#include <linux/units.h> + +#define MAX_NR_HW_SGPIO 64 + +#define NPCM_IOXCFG1 0x2A +#define NPCM_IOXCFG1_SFT_CLK GENMASK(3, 0) +#define NPCM_IOXCFG1_SCLK_POL BIT(4) +#define NPCM_IOXCFG1_LDSH_POL BIT(5) + +#define NPCM_IOXCTS 0x28 +#define NPCM_IOXCTS_IOXIF_EN BIT(7) +#define NPCM_IOXCTS_RD_MODE GENMASK(2, 1) +#define NPCM_IOXCTS_RD_MODE_PERIODIC BIT(2) + +#define NPCM_IOXCFG2 0x2B +#define NPCM_IOXCFG2_PORT GENMASK(3, 0) + +#define NPCM_IXOEVCFG_MASK GENMASK(1, 0) +#define NPCM_IXOEVCFG_FALLING BIT(1) +#define NPCM_IXOEVCFG_RISING BIT(0) +#define NPCM_IXOEVCFG_BOTH (NPCM_IXOEVCFG_FALLING | NPCM_IXOEVCFG_RISING) + +#define NPCM_CLK_MHZ (8 * HZ_PER_MHZ) +#define NPCM_750_OPT 6 +#define NPCM_845_OPT 5 + +#define GPIO_BANK(x) ((x) / 8) +#define GPIO_BIT(x) ((x) % 8) + +/* + * Select the frequency of shift clock. + * The shift clock is a division of the APB clock. + */ +struct npcm_clk_cfg { + unsigned int *sft_clk; + unsigned int *clk_sel; + unsigned int cfg_opt; +}; + +struct npcm_sgpio { + struct gpio_chip chip; + struct clk *pclk; + struct irq_chip intc; + raw_spinlock_t lock; + + void __iomem *base; + int irq; + u8 nin_sgpio; + u8 nout_sgpio; + u8 in_port; + u8 out_port; + u8 int_type[MAX_NR_HW_SGPIO]; +}; + +struct npcm_sgpio_bank { + u8 rdata_reg; + u8 wdata_reg; + u8 event_config; + u8 event_status; +}; + +enum npcm_sgpio_reg { + READ_DATA, + WRITE_DATA, + EVENT_CFG, + EVENT_STS, +}; + +static const struct npcm_sgpio_bank npcm_sgpio_banks[] = { + { + .wdata_reg = 0x00, + .rdata_reg = 0x08, + .event_config = 0x10, + .event_status = 0x20, + }, + { + .wdata_reg = 0x01, + .rdata_reg = 0x09, + .event_config = 0x12, + .event_status = 0x21, + }, + { + .wdata_reg = 0x02, + .rdata_reg = 0x0a, + .event_config = 0x14, + .event_status = 0x22, + }, + { + .wdata_reg = 0x03, + .rdata_reg = 0x0b, + .event_config = 0x16, + .event_status = 0x23, + }, + { + .wdata_reg = 0x04, + .rdata_reg = 0x0c, + .event_config = 0x18, + .event_status = 0x24, + }, + { + .wdata_reg = 0x05, + .rdata_reg = 0x0d, + .event_config = 0x1a, + .event_status = 0x25, + }, + { + .wdata_reg = 0x06, + .rdata_reg = 0x0e, + .event_config = 0x1c, + .event_status = 0x26, + }, + { + .wdata_reg = 0x07, + .rdata_reg = 0x0f, + .event_config = 0x1e, + .event_status = 0x27, + }, +}; + +static void __iomem *bank_reg(struct npcm_sgpio *gpio, + const struct npcm_sgpio_bank *bank, + const enum npcm_sgpio_reg reg) +{ + switch (reg) { + case READ_DATA: + return gpio->base + bank->rdata_reg; + case WRITE_DATA: + return gpio->base + bank->wdata_reg; + case EVENT_CFG: + return gpio->base + bank->event_config; + case EVENT_STS: + return gpio->base + bank->event_status; + default: + /* actually if code runs to here, it's an error case */ + dev_WARN(gpio->chip.parent, "Getting here is an error condition"); + return NULL; + } +} + +static const struct npcm_sgpio_bank *offset_to_bank(unsigned int offset) +{ + unsigned int bank = GPIO_BANK(offset); + + return &npcm_sgpio_banks[bank]; +} + +static void npcm_sgpio_irqd_to_data(struct irq_data *d, + struct npcm_sgpio **gpio, + const struct npcm_sgpio_bank **bank, + u8 *bit, unsigned int *offset) +{ + struct npcm_sgpio *internal; + + *offset = irqd_to_hwirq(d); + internal = irq_data_get_irq_chip_data(d); + + *gpio = internal; + *offset -= internal->nout_sgpio; + *bank = offset_to_bank(*offset); + *bit = GPIO_BIT(*offset); +} + +static int npcm_sgpio_init_port(struct npcm_sgpio *gpio) +{ + u8 in_port, out_port, set_port, reg; + + in_port = GPIO_BANK(gpio->nin_sgpio); + if (GPIO_BIT(gpio->nin_sgpio) > 0) + in_port += 1; + + out_port = GPIO_BANK(gpio->nout_sgpio); + if (GPIO_BIT(gpio->nout_sgpio) > 0) + out_port += 1; + + gpio->in_port = in_port; + gpio->out_port = out_port; + set_port = (out_port & NPCM_IOXCFG2_PORT) << 4 | + (in_port & NPCM_IOXCFG2_PORT); + iowrite8(set_port, gpio->base + NPCM_IOXCFG2); + + reg = ioread8(gpio->base + NPCM_IOXCFG2); + + return reg == set_port ? 0 : -EINVAL; + +} + +static int npcm_sgpio_dir_in(struct gpio_chip *gc, unsigned int offset) +{ + struct npcm_sgpio *gpio = gpiochip_get_data(gc); + + return offset < gpio->nout_sgpio ? -EINVAL : 0; + +} + +static int npcm_sgpio_dir_out(struct gpio_chip *gc, unsigned int offset, int val) +{ + gc->set(gc, offset, val); + + return 0; +} + +static int npcm_sgpio_get_direction(struct gpio_chip *gc, unsigned int offset) +{ + struct npcm_sgpio *gpio = gpiochip_get_data(gc); + + if (offset < gpio->nout_sgpio) + return GPIO_LINE_DIRECTION_OUT; + + return GPIO_LINE_DIRECTION_IN; +} + +static void npcm_sgpio_set(struct gpio_chip *gc, unsigned int offset, int val) +{ + struct npcm_sgpio *gpio = gpiochip_get_data(gc); + const struct npcm_sgpio_bank *bank = offset_to_bank(offset); + void __iomem *addr; + u8 reg = 0; + + addr = bank_reg(gpio, bank, WRITE_DATA); + reg = ioread8(addr); + + if (val) + reg |= BIT(GPIO_BIT(offset)); + else + reg &= ~BIT(GPIO_BIT(offset)); + + iowrite8(reg, addr); +} + +static int npcm_sgpio_get(struct gpio_chip *gc, unsigned int offset) +{ + struct npcm_sgpio *gpio = gpiochip_get_data(gc); + const struct npcm_sgpio_bank *bank; + void __iomem *addr; + u8 reg; + + if (offset < gpio->nout_sgpio) { + bank = offset_to_bank(offset); + addr = bank_reg(gpio, bank, WRITE_DATA); + } else { + offset -= gpio->nout_sgpio; + bank = offset_to_bank(offset); + addr = bank_reg(gpio, bank, READ_DATA); + } + + reg = ioread8(addr); + + return !!(reg & BIT(GPIO_BIT(offset))); +} + +static void npcm_sgpio_setup_enable(struct npcm_sgpio *gpio, bool enable) +{ + u8 reg; + + reg = ioread8(gpio->base + NPCM_IOXCTS); + reg = (reg & ~NPCM_IOXCTS_RD_MODE) | NPCM_IOXCTS_RD_MODE_PERIODIC; + + if (enable) + reg |= NPCM_IOXCTS_IOXIF_EN; + else + reg &= ~NPCM_IOXCTS_IOXIF_EN; + + iowrite8(reg, gpio->base + NPCM_IOXCTS); +} + +static int npcm_sgpio_setup_clk(struct npcm_sgpio *gpio, + const struct npcm_clk_cfg *clk_cfg) +{ + unsigned long apb_freq; + u32 val; + u8 tmp; + int i; + + apb_freq = clk_get_rate(gpio->pclk); + tmp = ioread8(gpio->base + NPCM_IOXCFG1) & ~NPCM_IOXCFG1_SFT_CLK; + + for (i = clk_cfg->cfg_opt-1; i > 0; i--) { + val = apb_freq / clk_cfg->sft_clk[i]; + if (NPCM_CLK_MHZ > val) { + iowrite8(clk_cfg->clk_sel[i] | tmp, + gpio->base + NPCM_IOXCFG1); + return 0; + } + } + + return -EINVAL; +} + +static void npcm_sgpio_irq_init_valid_mask(struct gpio_chip *gc, + unsigned long *valid_mask, + unsigned int ngpios) +{ + struct npcm_sgpio *gpio = gpiochip_get_data(gc); + + /* input GPIOs in the high range */ + bitmap_set(valid_mask, gpio->nout_sgpio, gpio->nin_sgpio); + bitmap_clear(valid_mask, 0, gpio->nout_sgpio); +} + +static void npcm_sgpio_irq_set_mask(struct irq_data *d, bool set) +{ + const struct npcm_sgpio_bank *bank; + struct npcm_sgpio *gpio; + unsigned long flags; + void __iomem *addr; + unsigned int offset; + u16 reg, type; + u8 bit; + + npcm_sgpio_irqd_to_data(d, &gpio, &bank, &bit, &offset); + addr = bank_reg(gpio, bank, EVENT_CFG); + + reg = ioread16(addr); + if (set) { + reg &= ~(NPCM_IXOEVCFG_MASK << (bit * 2)); + } else { + type = gpio->int_type[offset]; + reg |= (type << (bit * 2)); + } + + raw_spin_lock_irqsave(&gpio->lock, flags); + + npcm_sgpio_setup_enable(gpio, false); + + iowrite16(reg, addr); + + npcm_sgpio_setup_enable(gpio, true); + + addr = bank_reg(gpio, bank, EVENT_STS); + reg = ioread8(addr); + reg |= BIT(bit); + iowrite8(reg, addr); + + raw_spin_unlock_irqrestore(&gpio->lock, flags); +} + +static void npcm_sgpio_irq_ack(struct irq_data *d) +{ + const struct npcm_sgpio_bank *bank; + struct npcm_sgpio *gpio; + unsigned long flags; + void __iomem *status_addr; + unsigned int offset; + u8 bit; + + npcm_sgpio_irqd_to_data(d, &gpio, &bank, &bit, &offset); + status_addr = bank_reg(gpio, bank, EVENT_STS); + raw_spin_lock_irqsave(&gpio->lock, flags); + iowrite8(BIT(bit), status_addr); + raw_spin_unlock_irqrestore(&gpio->lock, flags); +} + +static void npcm_sgpio_irq_mask(struct irq_data *d) +{ + npcm_sgpio_irq_set_mask(d, true); +} + +static void npcm_sgpio_irq_unmask(struct irq_data *d) +{ + npcm_sgpio_irq_set_mask(d, false); +} + +static int npcm_sgpio_set_type(struct irq_data *d, unsigned int type) +{ + const struct npcm_sgpio_bank *bank; + irq_flow_handler_t handler; + struct npcm_sgpio *gpio; + unsigned long flags; + void __iomem *addr; + unsigned int offset; + u16 reg, val; + u8 bit; + + npcm_sgpio_irqd_to_data(d, &gpio, &bank, &bit, &offset); + + switch (type & IRQ_TYPE_SENSE_MASK) { + case IRQ_TYPE_EDGE_BOTH: + val = NPCM_IXOEVCFG_BOTH; + break; + case IRQ_TYPE_EDGE_RISING: + case IRQ_TYPE_LEVEL_HIGH: + val = NPCM_IXOEVCFG_RISING; + break; + case IRQ_TYPE_EDGE_FALLING: + case IRQ_TYPE_LEVEL_LOW: + val = NPCM_IXOEVCFG_FALLING; + break; + default: + return -EINVAL; + } + + if (type & IRQ_TYPE_LEVEL_MASK) + handler = handle_level_irq; + else + handler = handle_edge_irq; + + gpio->int_type[offset] = val; + + raw_spin_lock_irqsave(&gpio->lock, flags); + npcm_sgpio_setup_enable(gpio, false); + addr = bank_reg(gpio, bank, EVENT_CFG); + reg = ioread16(addr); + + reg |= (val << (bit * 2)); + + iowrite16(reg, addr); + npcm_sgpio_setup_enable(gpio, true); + raw_spin_unlock_irqrestore(&gpio->lock, flags); + + irq_set_handler_locked(d, handler); + + return 0; +} + +static void npcm_sgpio_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 npcm_sgpio *gpio = gpiochip_get_data(gc); + unsigned int i, j, girq; + unsigned long reg; + + chained_irq_enter(ic, desc); + + for (i = 0; i < ARRAY_SIZE(npcm_sgpio_banks); i++) { + const struct npcm_sgpio_bank *bank = &npcm_sgpio_banks[i]; + + reg = ioread8(bank_reg(gpio, bank, EVENT_STS)); + for_each_set_bit(j, ®, 8) { + girq = irq_find_mapping(gc->irq.domain, + i * 8 + gpio->nout_sgpio + j); + generic_handle_domain_irq(gc->irq.domain, girq); + } + } + + chained_irq_exit(ic, desc); +} + +static const struct irq_chip sgpio_irq_chip = { + .name = "sgpio-irq", + .irq_ack = npcm_sgpio_irq_ack, + .irq_mask = npcm_sgpio_irq_mask, + .irq_unmask = npcm_sgpio_irq_unmask, + .irq_set_type = npcm_sgpio_set_type, + .flags = IRQCHIP_IMMUTABLE | IRQCHIP_MASK_ON_SUSPEND, + GPIOCHIP_IRQ_RESOURCE_HELPERS, +}; + +static int npcm_sgpio_setup_irqs(struct npcm_sgpio *gpio, + struct platform_device *pdev) +{ + int rc, i; + struct gpio_irq_chip *irq; + + rc = platform_get_irq(pdev, 0); + if (rc < 0) + return rc; + + gpio->irq = rc; + + npcm_sgpio_setup_enable(gpio, false); + + /* Disable IRQ and clear Interrupt status registers for all SGPIO Pins. */ + for (i = 0; i < ARRAY_SIZE(npcm_sgpio_banks); i++) { + const struct npcm_sgpio_bank *bank = &npcm_sgpio_banks[i]; + + iowrite16(0, bank_reg(gpio, bank, EVENT_CFG)); + iowrite8(0xff, bank_reg(gpio, bank, EVENT_STS)); + } + + irq = &gpio->chip.irq; + gpio_irq_chip_set_chip(irq, &sgpio_irq_chip); + irq->init_valid_mask = npcm_sgpio_irq_init_valid_mask; + irq->handler = handle_bad_irq; + irq->default_type = IRQ_TYPE_NONE; + irq->parent_handler = npcm_sgpio_irq_handler; + irq->parent_handler_data = gpio; + irq->parents = &gpio->irq; + irq->num_parents = 1; + + return 0; +} + +static int npcm_sgpio_probe(struct platform_device *pdev) +{ + struct npcm_sgpio *gpio; + const struct npcm_clk_cfg *clk_cfg; + int rc; + u32 nin_gpios, nout_gpios; + + 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); + + clk_cfg = device_get_match_data(&pdev->dev); + if (!clk_cfg) + return -EINVAL; + + rc = device_property_read_u32(&pdev->dev, "nuvoton,input-ngpios", + &nin_gpios); + if (rc < 0) + return dev_err_probe(&pdev->dev, rc, "Could not read ngpios property\n"); + + rc = device_property_read_u32(&pdev->dev, "nuvoton,output-ngpios", + &nout_gpios); + if (rc < 0) + return dev_err_probe(&pdev->dev, rc, "Could not read ngpios property\n"); + + gpio->nin_sgpio = nin_gpios; + gpio->nout_sgpio = nout_gpios; + if (gpio->nin_sgpio > MAX_NR_HW_SGPIO || + gpio->nout_sgpio > MAX_NR_HW_SGPIO) + return dev_err_probe(&pdev->dev, -EINVAL, "Number of GPIOs exceeds the maximum of %d: input: %d output: %d\n", MAX_NR_HW_SGPIO, nin_gpios, nout_gpios); + + gpio->pclk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(gpio->pclk)) + return dev_err_probe(&pdev->dev, PTR_ERR(gpio->pclk), "Could not get pclk\n"); + + rc = npcm_sgpio_setup_clk(gpio, clk_cfg); + if (rc < 0) + return dev_err_probe(&pdev->dev, rc, "Failed to setup clock\n"); + + raw_spin_lock_init(&gpio->lock); + gpio->chip.parent = &pdev->dev; + gpio->chip.ngpio = gpio->nin_sgpio + gpio->nout_sgpio; + gpio->chip.direction_input = npcm_sgpio_dir_in; + gpio->chip.direction_output = npcm_sgpio_dir_out; + gpio->chip.get_direction = npcm_sgpio_get_direction; + gpio->chip.get = npcm_sgpio_get; + gpio->chip.set = npcm_sgpio_set; + gpio->chip.label = dev_name(&pdev->dev); + gpio->chip.base = -1; + + rc = npcm_sgpio_init_port(gpio); + if (rc < 0) + return rc; + + rc = npcm_sgpio_setup_irqs(gpio, pdev); + if (rc < 0) + return rc; + + rc = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio); + if (rc) + return dev_err_probe(&pdev->dev, rc, "GPIO registering failed\n"); + + npcm_sgpio_setup_enable(gpio, true); + + return 0; +} + +static unsigned int npcm750_SFT_CLK[NPCM_750_OPT] = { + 1024, 32, 8, 4, 3, 2, +}; + +static unsigned int npcm750_CLK_SEL[NPCM_750_OPT] = { + 0x00, 0x05, 0x07, 0x0C, 0x0D, 0x0E, +}; + +static unsigned int npcm845_SFT_CLK[NPCM_845_OPT] = { + 1024, 32, 16, 8, 4, +}; + +static unsigned int npcm845_CLK_SEL[NPCM_845_OPT] = { + 0x00, 0x05, 0x06, 0x07, 0x0C, +}; + +static struct npcm_clk_cfg npcm750_sgpio_pdata = { + .sft_clk = npcm750_SFT_CLK, + .clk_sel = npcm750_CLK_SEL, + .cfg_opt = NPCM_750_OPT, +}; + +static const struct npcm_clk_cfg npcm845_sgpio_pdata = { + .sft_clk = npcm845_SFT_CLK, + .clk_sel = npcm845_CLK_SEL, + .cfg_opt = NPCM_845_OPT, +}; + +static const struct of_device_id npcm_sgpio_of_table[] = { + { .compatible = "nuvoton,npcm750-sgpio", .data = &npcm750_sgpio_pdata, }, + { .compatible = "nuvoton,npcm845-sgpio", .data = &npcm845_sgpio_pdata, }, + {} +}; +MODULE_DEVICE_TABLE(of, npcm_sgpio_of_table); + +static struct platform_driver npcm_sgpio_driver = { + .driver = { + .name = KBUILD_MODNAME, + .of_match_table = npcm_sgpio_of_table, + }, + .probe = npcm_sgpio_probe, +}; +module_platform_driver(npcm_sgpio_driver); + +MODULE_AUTHOR("Jim Liu <jjliu0@nuvoton.com>"); +MODULE_AUTHOR("Joseph Liu <kwliu@nuvoton.com>"); +MODULE_DESCRIPTION("Nuvoton NPCM Serial GPIO Driver"); +MODULE_LICENSE("GPL v2"); |