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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/gpio/gpio-realtek-otto.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/gpio/gpio-realtek-otto.c')
-rw-r--r-- | drivers/gpio/gpio-realtek-otto.c | 459 |
1 files changed, 459 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-realtek-otto.c b/drivers/gpio/gpio-realtek-otto.c new file mode 100644 index 000000000..d6418f89d --- /dev/null +++ b/drivers/gpio/gpio-realtek-otto.c @@ -0,0 +1,459 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <linux/gpio/driver.h> +#include <linux/cpumask.h> +#include <linux/irq.h> +#include <linux/minmax.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/property.h> + +/* + * Total register block size is 0x1C for one bank of four ports (A, B, C, D). + * An optional second bank, with ports E, F, G, and H, may be present, starting + * at register offset 0x1C. + */ + +/* + * Pin select: (0) "normal", (1) "dedicate peripheral" + * Not used on RTL8380/RTL8390, peripheral selection is managed by control bits + * in the peripheral registers. + */ +#define REALTEK_GPIO_REG_CNR 0x00 +/* Clear bit (0) for input, set bit (1) for output */ +#define REALTEK_GPIO_REG_DIR 0x08 +#define REALTEK_GPIO_REG_DATA 0x0C +/* Read bit for IRQ status, write 1 to clear IRQ */ +#define REALTEK_GPIO_REG_ISR 0x10 +/* Two bits per GPIO in IMR registers */ +#define REALTEK_GPIO_REG_IMR 0x14 +#define REALTEK_GPIO_REG_IMR_AB 0x14 +#define REALTEK_GPIO_REG_IMR_CD 0x18 +#define REALTEK_GPIO_IMR_LINE_MASK GENMASK(1, 0) +#define REALTEK_GPIO_IRQ_EDGE_FALLING 1 +#define REALTEK_GPIO_IRQ_EDGE_RISING 2 +#define REALTEK_GPIO_IRQ_EDGE_BOTH 3 + +#define REALTEK_GPIO_MAX 32 +#define REALTEK_GPIO_PORTS_PER_BANK 4 + +/** + * realtek_gpio_ctrl - Realtek Otto GPIO driver data + * + * @gc: Associated gpio_chip instance + * @base: Base address of the register block for a GPIO bank + * @lock: Lock for accessing the IRQ registers and values + * @intr_mask: Mask for interrupts lines + * @intr_type: Interrupt type selection + * @bank_read: Read a bank setting as a single 32-bit value + * @bank_write: Write a bank setting as a single 32-bit value + * @imr_line_pos: Bit shift of an IRQ line's IMR value. + * + * The DIR, DATA, and ISR registers consist of four 8-bit port values, packed + * into a single 32-bit register. Use @bank_read (@bank_write) to get (assign) + * a value from (to) these registers. The IMR register consists of four 16-bit + * port values, packed into two 32-bit registers. Use @imr_line_pos to get the + * bit shift of the 2-bit field for a line's IMR settings. Shifts larger than + * 32 overflow into the second register. + * + * Because the interrupt mask register (IMR) combines the function of IRQ type + * selection and masking, two extra values are stored. @intr_mask is used to + * mask/unmask the interrupts for a GPIO line, and @intr_type is used to store + * the selected interrupt types. The logical AND of these values is written to + * IMR on changes. + */ +struct realtek_gpio_ctrl { + struct gpio_chip gc; + void __iomem *base; + void __iomem *cpumask_base; + struct cpumask cpu_irq_maskable; + raw_spinlock_t lock; + u8 intr_mask[REALTEK_GPIO_MAX]; + u8 intr_type[REALTEK_GPIO_MAX]; + u32 (*bank_read)(void __iomem *reg); + void (*bank_write)(void __iomem *reg, u32 value); + unsigned int (*line_imr_pos)(unsigned int line); +}; + +/* Expand with more flags as devices with other quirks are added */ +enum realtek_gpio_flags { + /* + * Allow disabling interrupts, for cases where the port order is + * unknown. This may result in a port mismatch between ISR and IMR. + * An interrupt would appear to come from a different line than the + * line the IRQ handler was assigned to, causing uncaught interrupts. + */ + GPIO_INTERRUPTS_DISABLED = BIT(0), + /* + * Port order is reversed, meaning DCBA register layout for 1-bit + * fields, and [BA, DC] for 2-bit fields. + */ + GPIO_PORTS_REVERSED = BIT(1), + /* + * Interrupts can be enabled per cpu. This requires a secondary IO + * range, where the per-cpu enable masks are located. + */ + GPIO_INTERRUPTS_PER_CPU = BIT(2), +}; + +static struct realtek_gpio_ctrl *irq_data_to_ctrl(struct irq_data *data) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(data); + + return container_of(gc, struct realtek_gpio_ctrl, gc); +} + +/* + * Normal port order register access + * + * Port information is stored with the first port at offset 0, followed by the + * second, etc. Most registers store one bit per GPIO and use a u8 value per + * port. The two interrupt mask registers store two bits per GPIO, so use u16 + * values. + */ +static u32 realtek_gpio_bank_read_swapped(void __iomem *reg) +{ + return ioread32be(reg); +} + +static void realtek_gpio_bank_write_swapped(void __iomem *reg, u32 value) +{ + iowrite32be(value, reg); +} + +static unsigned int realtek_gpio_line_imr_pos_swapped(unsigned int line) +{ + unsigned int port_pin = line % 8; + unsigned int port = line / 8; + + return 2 * (8 * (port ^ 1) + port_pin); +} + +/* + * Reversed port order register access + * + * For registers with one bit per GPIO, all ports are stored as u8-s in one + * register in reversed order. The two interrupt mask registers store two bits + * per GPIO, so use u16 values. The first register contains ports 1 and 0, the + * second ports 3 and 2. + */ +static u32 realtek_gpio_bank_read(void __iomem *reg) +{ + return ioread32(reg); +} + +static void realtek_gpio_bank_write(void __iomem *reg, u32 value) +{ + iowrite32(value, reg); +} + +static unsigned int realtek_gpio_line_imr_pos(unsigned int line) +{ + return 2 * line; +} + +static void realtek_gpio_clear_isr(struct realtek_gpio_ctrl *ctrl, u32 mask) +{ + ctrl->bank_write(ctrl->base + REALTEK_GPIO_REG_ISR, mask); +} + +static u32 realtek_gpio_read_isr(struct realtek_gpio_ctrl *ctrl) +{ + return ctrl->bank_read(ctrl->base + REALTEK_GPIO_REG_ISR); +} + +/* Set the rising and falling edge mask bits for a GPIO pin */ +static void realtek_gpio_update_line_imr(struct realtek_gpio_ctrl *ctrl, unsigned int line) +{ + void __iomem *reg = ctrl->base + REALTEK_GPIO_REG_IMR; + unsigned int line_shift = ctrl->line_imr_pos(line); + unsigned int shift = line_shift % 32; + u32 irq_type = ctrl->intr_type[line]; + u32 irq_mask = ctrl->intr_mask[line]; + u32 reg_val; + + reg += 4 * (line_shift / 32); + reg_val = ioread32(reg); + reg_val &= ~(REALTEK_GPIO_IMR_LINE_MASK << shift); + reg_val |= (irq_type & irq_mask & REALTEK_GPIO_IMR_LINE_MASK) << shift; + iowrite32(reg_val, reg); +} + +static void realtek_gpio_irq_ack(struct irq_data *data) +{ + struct realtek_gpio_ctrl *ctrl = irq_data_to_ctrl(data); + irq_hw_number_t line = irqd_to_hwirq(data); + + realtek_gpio_clear_isr(ctrl, BIT(line)); +} + +static void realtek_gpio_irq_unmask(struct irq_data *data) +{ + struct realtek_gpio_ctrl *ctrl = irq_data_to_ctrl(data); + unsigned int line = irqd_to_hwirq(data); + unsigned long flags; + + gpiochip_enable_irq(&ctrl->gc, line); + + raw_spin_lock_irqsave(&ctrl->lock, flags); + ctrl->intr_mask[line] = REALTEK_GPIO_IMR_LINE_MASK; + realtek_gpio_update_line_imr(ctrl, line); + raw_spin_unlock_irqrestore(&ctrl->lock, flags); +} + +static void realtek_gpio_irq_mask(struct irq_data *data) +{ + struct realtek_gpio_ctrl *ctrl = irq_data_to_ctrl(data); + unsigned int line = irqd_to_hwirq(data); + unsigned long flags; + + raw_spin_lock_irqsave(&ctrl->lock, flags); + ctrl->intr_mask[line] = 0; + realtek_gpio_update_line_imr(ctrl, line); + raw_spin_unlock_irqrestore(&ctrl->lock, flags); + + gpiochip_disable_irq(&ctrl->gc, line); +} + +static int realtek_gpio_irq_set_type(struct irq_data *data, unsigned int flow_type) +{ + struct realtek_gpio_ctrl *ctrl = irq_data_to_ctrl(data); + unsigned int line = irqd_to_hwirq(data); + unsigned long flags; + u8 type; + + switch (flow_type & IRQ_TYPE_SENSE_MASK) { + case IRQ_TYPE_EDGE_FALLING: + type = REALTEK_GPIO_IRQ_EDGE_FALLING; + break; + case IRQ_TYPE_EDGE_RISING: + type = REALTEK_GPIO_IRQ_EDGE_RISING; + break; + case IRQ_TYPE_EDGE_BOTH: + type = REALTEK_GPIO_IRQ_EDGE_BOTH; + break; + default: + return -EINVAL; + } + + irq_set_handler_locked(data, handle_edge_irq); + + raw_spin_lock_irqsave(&ctrl->lock, flags); + ctrl->intr_type[line] = type; + realtek_gpio_update_line_imr(ctrl, line); + raw_spin_unlock_irqrestore(&ctrl->lock, flags); + + return 0; +} + +static void realtek_gpio_irq_handler(struct irq_desc *desc) +{ + struct gpio_chip *gc = irq_desc_get_handler_data(desc); + struct realtek_gpio_ctrl *ctrl = gpiochip_get_data(gc); + struct irq_chip *irq_chip = irq_desc_get_chip(desc); + unsigned long status; + int offset; + + chained_irq_enter(irq_chip, desc); + + status = realtek_gpio_read_isr(ctrl); + for_each_set_bit(offset, &status, gc->ngpio) + generic_handle_domain_irq(gc->irq.domain, offset); + + chained_irq_exit(irq_chip, desc); +} + +static inline void __iomem *realtek_gpio_irq_cpu_mask(struct realtek_gpio_ctrl *ctrl, int cpu) +{ + return ctrl->cpumask_base + REALTEK_GPIO_PORTS_PER_BANK * cpu; +} + +static int realtek_gpio_irq_set_affinity(struct irq_data *data, + const struct cpumask *dest, bool force) +{ + struct realtek_gpio_ctrl *ctrl = irq_data_to_ctrl(data); + unsigned int line = irqd_to_hwirq(data); + void __iomem *irq_cpu_mask; + unsigned long flags; + int cpu; + u32 v; + + if (!ctrl->cpumask_base) + return -ENXIO; + + raw_spin_lock_irqsave(&ctrl->lock, flags); + + for_each_cpu(cpu, &ctrl->cpu_irq_maskable) { + irq_cpu_mask = realtek_gpio_irq_cpu_mask(ctrl, cpu); + v = ctrl->bank_read(irq_cpu_mask); + + if (cpumask_test_cpu(cpu, dest)) + v |= BIT(line); + else + v &= ~BIT(line); + + ctrl->bank_write(irq_cpu_mask, v); + } + + raw_spin_unlock_irqrestore(&ctrl->lock, flags); + + irq_data_update_effective_affinity(data, dest); + + return 0; +} + +static int realtek_gpio_irq_init(struct gpio_chip *gc) +{ + struct realtek_gpio_ctrl *ctrl = gpiochip_get_data(gc); + u32 mask_all = GENMASK(gc->ngpio - 1, 0); + unsigned int line; + int cpu; + + for (line = 0; line < gc->ngpio; line++) + realtek_gpio_update_line_imr(ctrl, line); + + realtek_gpio_clear_isr(ctrl, mask_all); + + for_each_cpu(cpu, &ctrl->cpu_irq_maskable) + ctrl->bank_write(realtek_gpio_irq_cpu_mask(ctrl, cpu), mask_all); + + return 0; +} + +static const struct irq_chip realtek_gpio_irq_chip = { + .name = "realtek-otto-gpio", + .irq_ack = realtek_gpio_irq_ack, + .irq_mask = realtek_gpio_irq_mask, + .irq_unmask = realtek_gpio_irq_unmask, + .irq_set_type = realtek_gpio_irq_set_type, + .irq_set_affinity = realtek_gpio_irq_set_affinity, + .flags = IRQCHIP_IMMUTABLE, + GPIOCHIP_IRQ_RESOURCE_HELPERS, +}; + +static const struct of_device_id realtek_gpio_of_match[] = { + { + .compatible = "realtek,otto-gpio", + .data = (void *)GPIO_INTERRUPTS_DISABLED, + }, + { + .compatible = "realtek,rtl8380-gpio", + }, + { + .compatible = "realtek,rtl8390-gpio", + }, + { + .compatible = "realtek,rtl9300-gpio", + .data = (void *)(GPIO_PORTS_REVERSED | GPIO_INTERRUPTS_PER_CPU) + }, + { + .compatible = "realtek,rtl9310-gpio", + }, + {} +}; +MODULE_DEVICE_TABLE(of, realtek_gpio_of_match); + +static int realtek_gpio_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + unsigned long bgpio_flags; + unsigned int dev_flags; + struct gpio_irq_chip *girq; + struct realtek_gpio_ctrl *ctrl; + struct resource *res; + u32 ngpios; + unsigned int nr_cpus; + int cpu, err, irq; + + ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL); + if (!ctrl) + return -ENOMEM; + + dev_flags = (unsigned int) device_get_match_data(dev); + + ngpios = REALTEK_GPIO_MAX; + device_property_read_u32(dev, "ngpios", &ngpios); + + if (ngpios > REALTEK_GPIO_MAX) { + dev_err(&pdev->dev, "invalid ngpios (max. %d)\n", + REALTEK_GPIO_MAX); + return -EINVAL; + } + + ctrl->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(ctrl->base)) + return PTR_ERR(ctrl->base); + + raw_spin_lock_init(&ctrl->lock); + + if (dev_flags & GPIO_PORTS_REVERSED) { + bgpio_flags = 0; + ctrl->bank_read = realtek_gpio_bank_read; + ctrl->bank_write = realtek_gpio_bank_write; + ctrl->line_imr_pos = realtek_gpio_line_imr_pos; + } else { + bgpio_flags = BGPIOF_BIG_ENDIAN_BYTE_ORDER; + ctrl->bank_read = realtek_gpio_bank_read_swapped; + ctrl->bank_write = realtek_gpio_bank_write_swapped; + ctrl->line_imr_pos = realtek_gpio_line_imr_pos_swapped; + } + + err = bgpio_init(&ctrl->gc, dev, 4, + ctrl->base + REALTEK_GPIO_REG_DATA, NULL, NULL, + ctrl->base + REALTEK_GPIO_REG_DIR, NULL, + bgpio_flags); + if (err) { + dev_err(dev, "unable to init generic GPIO"); + return err; + } + + ctrl->gc.ngpio = ngpios; + ctrl->gc.owner = THIS_MODULE; + + irq = platform_get_irq_optional(pdev, 0); + if (!(dev_flags & GPIO_INTERRUPTS_DISABLED) && irq > 0) { + girq = &ctrl->gc.irq; + gpio_irq_chip_set_chip(girq, &realtek_gpio_irq_chip); + girq->default_type = IRQ_TYPE_NONE; + girq->handler = handle_bad_irq; + girq->parent_handler = realtek_gpio_irq_handler; + girq->num_parents = 1; + girq->parents = devm_kcalloc(dev, girq->num_parents, + sizeof(*girq->parents), GFP_KERNEL); + if (!girq->parents) + return -ENOMEM; + girq->parents[0] = irq; + girq->init_hw = realtek_gpio_irq_init; + } + + cpumask_clear(&ctrl->cpu_irq_maskable); + + if ((dev_flags & GPIO_INTERRUPTS_PER_CPU) && irq > 0) { + ctrl->cpumask_base = devm_platform_get_and_ioremap_resource(pdev, 1, &res); + if (IS_ERR(ctrl->cpumask_base)) + return dev_err_probe(dev, PTR_ERR(ctrl->cpumask_base), + "missing CPU IRQ mask registers"); + + nr_cpus = resource_size(res) / REALTEK_GPIO_PORTS_PER_BANK; + nr_cpus = min(nr_cpus, num_present_cpus()); + + for (cpu = 0; cpu < nr_cpus; cpu++) + cpumask_set_cpu(cpu, &ctrl->cpu_irq_maskable); + } + + return devm_gpiochip_add_data(dev, &ctrl->gc, ctrl); +} + +static struct platform_driver realtek_gpio_driver = { + .driver = { + .name = "realtek-otto-gpio", + .of_match_table = realtek_gpio_of_match, + }, + .probe = realtek_gpio_probe, +}; +module_platform_driver(realtek_gpio_driver); + +MODULE_DESCRIPTION("Realtek Otto GPIO support"); +MODULE_AUTHOR("Sander Vanheule <sander@svanheule.net>"); +MODULE_LICENSE("GPL v2"); |