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Subject[v6 2/2] gpio: aspeed: Add SGPIO driver
Date
Add SGPIO driver support for Aspeed AST2500 SoC.

Signed-off-by: Hongwei Zhang <hongweiz@ami.com>
---
drivers/gpio/sgpio-aspeed.c | 521 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 521 insertions(+)
create mode 100644 drivers/gpio/sgpio-aspeed.c

diff --git a/drivers/gpio/sgpio-aspeed.c b/drivers/gpio/sgpio-aspeed.c
new file mode 100644
index 0000000..9a17b1a
--- /dev/null
+++ b/drivers/gpio/sgpio-aspeed.c
@@ -0,0 +1,521 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2019 American Megatrends International LLC.
+ *
+ * Author: Karthikeyan Mani <karthikeyanm@amiindia.co.in>
+ */
+
+#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/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+
+#define MAX_NR_SGPIO 80
+
+#define ASPEED_SGPIO_CTRL 0x54
+
+#define ASPEED_SGPIO_PINS_MASK GENMASK(9, 6)
+#define ASPEED_SGPIO_CLK_DIV_MASK GENMASK(31, 16)
+#define ASPEED_SGPIO_ENABLE BIT(0)
+
+struct aspeed_sgpio {
+ struct gpio_chip chip;
+ struct clk *pclk;
+ spinlock_t lock;
+ void __iomem *base;
+ uint32_t dir_in[3];
+ int irq;
+};
+
+struct aspeed_sgpio_bank {
+ uint16_t val_regs;
+ uint16_t rdata_reg;
+ uint16_t irq_regs;
+ const char names[4][3];
+};
+
+/*
+ * Note: The "value" register returns the input value when the GPIO is
+ * configured as an input.
+ *
+ * The "rdata" register returns the output value when the GPIO is
+ * configured as an output.
+ */
+static const struct aspeed_sgpio_bank aspeed_sgpio_banks[] = {
+ {
+ .val_regs = 0x0000,
+ .rdata_reg = 0x0070,
+ .irq_regs = 0x0004,
+ .names = { "A", "B", "C", "D" },
+ },
+ {
+ .val_regs = 0x001C,
+ .rdata_reg = 0x0074,
+ .irq_regs = 0x0020,
+ .names = { "E", "F", "G", "H" },
+ },
+ {
+ .val_regs = 0x0038,
+ .rdata_reg = 0x0078,
+ .irq_regs = 0x003C,
+ .names = { "I", "J" },
+ },
+};
+
+enum aspeed_sgpio_reg {
+ reg_val,
+ reg_rdata,
+ reg_irq_enable,
+ reg_irq_type0,
+ reg_irq_type1,
+ reg_irq_type2,
+ reg_irq_status,
+};
+
+#define GPIO_VAL_VALUE 0x00
+#define GPIO_IRQ_ENABLE 0x00
+#define GPIO_IRQ_TYPE0 0x04
+#define GPIO_IRQ_TYPE1 0x08
+#define GPIO_IRQ_TYPE2 0x0C
+#define GPIO_IRQ_STATUS 0x10
+
+static void __iomem *bank_reg(struct aspeed_sgpio *gpio,
+ const struct aspeed_sgpio_bank *bank,
+ const enum aspeed_sgpio_reg reg)
+{
+ switch (reg) {
+ case reg_val:
+ return gpio->base + bank->val_regs + GPIO_VAL_VALUE;
+ case reg_rdata:
+ return gpio->base + bank->rdata_reg;
+ case reg_irq_enable:
+ return gpio->base + bank->irq_regs + GPIO_IRQ_ENABLE;
+ case reg_irq_type0:
+ return gpio->base + bank->irq_regs + GPIO_IRQ_TYPE0;
+ case reg_irq_type1:
+ return gpio->base + bank->irq_regs + GPIO_IRQ_TYPE1;
+ case reg_irq_type2:
+ return gpio->base + bank->irq_regs + GPIO_IRQ_TYPE2;
+ case reg_irq_status:
+ return gpio->base + bank->irq_regs + GPIO_IRQ_STATUS;
+ default:
+ /* acturally if code runs to here, it's an error case */
+ BUG_ON(1);
+ }
+}
+
+#define GPIO_BANK(x) ((x) >> 5)
+#define GPIO_OFFSET(x) ((x) & 0x1f)
+#define GPIO_BIT(x) BIT(GPIO_OFFSET(x))
+
+static const struct aspeed_sgpio_bank *to_bank(unsigned int offset)
+{
+ unsigned int bank = GPIO_BANK(offset);
+
+ WARN_ON(bank >= ARRAY_SIZE(aspeed_sgpio_banks));
+ return &aspeed_sgpio_banks[bank];
+}
+
+static int aspeed_sgpio_get(struct gpio_chip *gc, unsigned int offset)
+{
+ struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
+ const struct aspeed_sgpio_bank *bank = to_bank(offset);
+ unsigned long flags;
+ enum aspeed_sgpio_reg reg;
+ bool is_input;
+ int rc = 0;
+
+ spin_lock_irqsave(&gpio->lock, flags);
+
+ is_input = gpio->dir_in[GPIO_BANK(offset)] & GPIO_BIT(offset);
+ reg = is_input ? reg_val : reg_rdata;
+ rc = !!(ioread32(bank_reg(gpio, bank, reg)) & GPIO_BIT(offset));
+
+ spin_unlock_irqrestore(&gpio->lock, flags);
+
+ return rc;
+}
+
+static void aspeed_sgpio_set(struct gpio_chip *gc, unsigned int offset, int val)
+{
+ struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
+ const struct aspeed_sgpio_bank *bank = to_bank(offset);
+ unsigned long flags;
+ void __iomem *addr;
+ u32 reg = 0;
+
+ spin_lock_irqsave(&gpio->lock, flags);
+
+ addr = bank_reg(gpio, bank, reg_val);
+
+ if (val)
+ reg |= GPIO_BIT(offset);
+ else
+ reg &= ~GPIO_BIT(offset);
+
+ iowrite32(reg, addr);
+
+ spin_unlock_irqrestore(&gpio->lock, flags);
+}
+
+static int aspeed_sgpio_dir_in(struct gpio_chip *gc, unsigned int offset)
+{
+ struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
+ unsigned long flags;
+
+ spin_lock_irqsave(&gpio->lock, flags);
+ gpio->dir_in[GPIO_BANK(offset)] |= GPIO_BIT(offset);
+ spin_unlock_irqrestore(&gpio->lock, flags);
+
+ return 0;
+}
+
+static int aspeed_sgpio_dir_out(struct gpio_chip *gc, unsigned int offset, int val)
+{
+ struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
+ unsigned long flags;
+
+ spin_lock_irqsave(&gpio->lock, flags);
+ gpio->dir_in[GPIO_BANK(offset)] &= ~GPIO_BIT(offset);
+ spin_unlock_irqrestore(&gpio->lock, flags);
+
+ aspeed_sgpio_set(gc, offset, val);
+
+ return 0;
+}
+
+static int aspeed_sgpio_get_direction(struct gpio_chip *gc, unsigned int offset)
+{
+ int dir_status;
+ struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
+ unsigned long flags;
+
+ spin_lock_irqsave(&gpio->lock, flags);
+ dir_status = gpio->dir_in[GPIO_BANK(offset)] & GPIO_BIT(offset);
+ spin_unlock_irqrestore(&gpio->lock, flags);
+
+ return dir_status;
+
+}
+
+static void irqd_to_aspeed_sgpio_data(struct irq_data *d,
+ struct aspeed_sgpio **gpio,
+ const struct aspeed_sgpio_bank **bank,
+ u32 *bit, int *offset)
+{
+ struct aspeed_sgpio *internal;
+
+ *offset = irqd_to_hwirq(d);
+ internal = irq_data_get_irq_chip_data(d);
+ WARN_ON(!internal);
+
+ *gpio = internal;
+ *bank = to_bank(*offset);
+ *bit = GPIO_BIT(*offset);
+}
+
+static void aspeed_sgpio_irq_ack(struct irq_data *d)
+{
+ const struct aspeed_sgpio_bank *bank;
+ struct aspeed_sgpio *gpio;
+ unsigned long flags;
+ void __iomem *status_addr;
+ int offset;
+ u32 bit;
+
+ irqd_to_aspeed_sgpio_data(d, &gpio, &bank, &bit, &offset);
+
+ status_addr = bank_reg(gpio, bank, reg_irq_status);
+
+ spin_lock_irqsave(&gpio->lock, flags);
+
+ iowrite32(bit, status_addr);
+
+ spin_unlock_irqrestore(&gpio->lock, flags);
+}
+
+static void aspeed_sgpio_irq_set_mask(struct irq_data *d, bool set)
+{
+ const struct aspeed_sgpio_bank *bank;
+ struct aspeed_sgpio *gpio;
+ unsigned long flags;
+ u32 reg, bit;
+ void __iomem *addr;
+ int offset;
+
+ irqd_to_aspeed_sgpio_data(d, &gpio, &bank, &bit, &offset);
+ addr = bank_reg(gpio, bank, reg_irq_enable);
+
+ spin_lock_irqsave(&gpio->lock, flags);
+
+ reg = ioread32(addr);
+ if (set)
+ reg |= bit;
+ else
+ reg &= ~bit;
+
+ iowrite32(reg, addr);
+
+ spin_unlock_irqrestore(&gpio->lock, flags);
+}
+
+static void aspeed_sgpio_irq_mask(struct irq_data *d)
+{
+ aspeed_sgpio_irq_set_mask(d, false);
+}
+
+static void aspeed_sgpio_irq_unmask(struct irq_data *d)
+{
+ aspeed_sgpio_irq_set_mask(d, true);
+}
+
+static int aspeed_sgpio_set_type(struct irq_data *d, unsigned int type)
+{
+ u32 type0 = 0;
+ u32 type1 = 0;
+ u32 type2 = 0;
+ u32 bit, reg;
+ const struct aspeed_sgpio_bank *bank;
+ irq_flow_handler_t handler;
+ struct aspeed_sgpio *gpio;
+ unsigned long flags;
+ void __iomem *addr;
+ int offset;
+
+ irqd_to_aspeed_sgpio_data(d, &gpio, &bank, &bit, &offset);
+
+ switch (type & IRQ_TYPE_SENSE_MASK) {
+ case IRQ_TYPE_EDGE_BOTH:
+ type2 |= bit;
+ /* fall through */
+ case IRQ_TYPE_EDGE_RISING:
+ type0 |= bit;
+ /* fall through */
+ case IRQ_TYPE_EDGE_FALLING:
+ handler = handle_edge_irq;
+ break;
+ case IRQ_TYPE_LEVEL_HIGH:
+ type0 |= bit;
+ /* fall through */
+ case IRQ_TYPE_LEVEL_LOW:
+ type1 |= bit;
+ handler = handle_level_irq;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ spin_lock_irqsave(&gpio->lock, flags);
+
+ addr = bank_reg(gpio, bank, reg_irq_type0);
+ reg = ioread32(addr);
+ reg = (reg & ~bit) | type0;
+ iowrite32(reg, addr);
+
+ addr = bank_reg(gpio, bank, reg_irq_type1);
+ reg = ioread32(addr);
+ reg = (reg & ~bit) | type1;
+ iowrite32(reg, addr);
+
+ addr = bank_reg(gpio, bank, reg_irq_type2);
+ reg = ioread32(addr);
+ reg = (reg & ~bit) | type2;
+ iowrite32(reg, addr);
+
+ spin_unlock_irqrestore(&gpio->lock, flags);
+
+ irq_set_handler_locked(d, handler);
+
+ return 0;
+}
+
+static void aspeed_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 aspeed_sgpio *data = gpiochip_get_data(gc);
+ unsigned int i, p, girq;
+ unsigned long reg;
+
+ chained_irq_enter(ic, desc);
+
+ for (i = 0; i < ARRAY_SIZE(aspeed_sgpio_banks); i++) {
+ const struct aspeed_sgpio_bank *bank = &aspeed_sgpio_banks[i];
+
+ reg = ioread32(bank_reg(data, bank, reg_irq_status));
+
+ for_each_set_bit(p, &reg, 32) {
+ girq = irq_find_mapping(gc->irq.domain, i * 32 + p);
+ generic_handle_irq(girq);
+ }
+
+ }
+
+ chained_irq_exit(ic, desc);
+}
+
+static struct irq_chip aspeed_sgpio_irqchip = {
+ .name = "aspeed-sgpio",
+ .irq_ack = aspeed_sgpio_irq_ack,
+ .irq_mask = aspeed_sgpio_irq_mask,
+ .irq_unmask = aspeed_sgpio_irq_unmask,
+ .irq_set_type = aspeed_sgpio_set_type,
+};
+
+static int aspeed_sgpio_setup_irqs(struct aspeed_sgpio *gpio,
+ struct platform_device *pdev)
+{
+ int rc, i;
+ const struct aspeed_sgpio_bank *bank;
+
+ rc = platform_get_irq(pdev, 0);
+ if (rc < 0)
+ return rc;
+
+ gpio->irq = rc;
+
+ /* Disable IRQ and clear Interrupt status registers for all SPGIO Pins. */
+ for (i = 0; i < ARRAY_SIZE(aspeed_sgpio_banks); i++) {
+ bank = &aspeed_sgpio_banks[i];
+ /* disable irq enable bits */
+ iowrite32(0x00000000, bank_reg(gpio, bank, reg_irq_enable));
+ /* clear status bits */
+ iowrite32(0xffffffff, bank_reg(gpio, bank, reg_irq_status));
+ }
+
+ rc = gpiochip_irqchip_add(&gpio->chip, &aspeed_sgpio_irqchip,
+ 0, handle_bad_irq, IRQ_TYPE_NONE);
+ if (rc) {
+ dev_info(&pdev->dev, "Could not add irqchip\n");
+ return rc;
+ }
+
+ gpiochip_set_chained_irqchip(&gpio->chip, &aspeed_sgpio_irqchip,
+ gpio->irq, aspeed_sgpio_irq_handler);
+
+ /* set IRQ settings and Enable Interrupt */
+ for (i = 0; i < ARRAY_SIZE(aspeed_sgpio_banks); i++) {
+ bank = &aspeed_sgpio_banks[i];
+ /* set falling or level-low irq */
+ iowrite32(0x00000000, bank_reg(gpio, bank, reg_irq_type0));
+ /* trigger type is edge */
+ iowrite32(0x00000000, bank_reg(gpio, bank, reg_irq_type1));
+ /* dual edge trigger mode. */
+ iowrite32(0xffffffff, bank_reg(gpio, bank, reg_irq_type2));
+ /* enable irq */
+ iowrite32(0xffffffff, bank_reg(gpio, bank, reg_irq_enable));
+ }
+
+ return 0;
+}
+
+static const struct of_device_id aspeed_sgpio_of_table[] = {
+ { .compatible = "aspeed,ast2400-sgpio" },
+ { .compatible = "aspeed,ast2500-sgpio" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, aspeed_sgpio_of_table);
+
+static int __init aspeed_sgpio_probe(struct platform_device *pdev)
+{
+ struct aspeed_sgpio *gpio;
+ u32 nr_gpios, sgpio_freq, sgpio_clk_div;
+ int rc;
+ unsigned long apb_freq;
+
+ 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);
+
+ rc = of_property_read_u32(pdev->dev.of_node, "ngpios", &nr_gpios);
+ if (rc < 0) {
+ dev_err(&pdev->dev, "Could not read ngpios property\n");
+ return -EINVAL;
+ } else if (nr_gpios > MAX_NR_SGPIO) {
+ dev_err(&pdev->dev, "Number of GPIOs exceeds the maximum of %d: %d\n",
+ MAX_NR_SGPIO, nr_gpios);
+ return -EINVAL;
+ }
+
+ rc = of_property_read_u32(pdev->dev.of_node, "bus-frequency", &sgpio_freq);
+ if (rc < 0) {
+ dev_err(&pdev->dev, "Could not read bus-frequency property\n");
+ return -EINVAL;
+ }
+
+ gpio->pclk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(gpio->pclk)) {
+ dev_err(&pdev->dev, "devm_clk_get failed\n");
+ return PTR_ERR(gpio->pclk);
+ }
+
+ apb_freq = clk_get_rate(gpio->pclk);
+
+ /*
+ * From the datasheet,
+ * SGPIO period = 1/PCLK * 2 * (GPIO254[31:16] + 1)
+ * period = 2 * (GPIO254[31:16] + 1) / PCLK
+ * frequency = 1 / (2 * (GPIO254[31:16] + 1) / PCLK)
+ * frequency = PCLK / (2 * (GPIO254[31:16] + 1))
+ * frequency * 2 * (GPIO254[31:16] + 1) = PCLK
+ * GPIO254[31:16] = PCLK / (frequency * 2) - 1
+ */
+ if (sgpio_freq == 0)
+ return -EINVAL;
+
+ sgpio_clk_div = (apb_freq / (sgpio_freq * 2)) - 1;
+
+ if (sgpio_clk_div > (1 << 16) - 1)
+ return -EINVAL;
+
+ iowrite32(FIELD_PREP(ASPEED_SGPIO_CLK_DIV_MASK, sgpio_clk_div) |
+ FIELD_PREP(ASPEED_SGPIO_PINS_MASK, (nr_gpios / 8)) |
+ ASPEED_SGPIO_ENABLE,
+ gpio->base + ASPEED_SGPIO_CTRL);
+
+ spin_lock_init(&gpio->lock);
+
+ gpio->chip.parent = &pdev->dev;
+ gpio->chip.ngpio = nr_gpios;
+ gpio->chip.direction_input = aspeed_sgpio_dir_in;
+ gpio->chip.direction_output = aspeed_sgpio_dir_out;
+ gpio->chip.get_direction = aspeed_sgpio_get_direction;
+ gpio->chip.request = NULL;
+ gpio->chip.free = NULL;
+ gpio->chip.get = aspeed_sgpio_get;
+ gpio->chip.set = aspeed_sgpio_set;
+ gpio->chip.set_config = NULL;
+ gpio->chip.label = dev_name(&pdev->dev);
+ gpio->chip.base = -1;
+
+ /* set all SGPIO pins as input (1). */
+ memset(gpio->dir_in, 0xff, sizeof(gpio->dir_in));
+
+ rc = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);
+ if (rc < 0)
+ return rc;
+
+ return aspeed_sgpio_setup_irqs(gpio, pdev);
+}
+
+static struct platform_driver aspeed_sgpio_driver = {
+ .driver = {
+ .name = KBUILD_MODNAME,
+ .of_match_table = aspeed_sgpio_of_table,
+ },
+};
+
+module_platform_driver_probe(aspeed_sgpio_driver, aspeed_sgpio_probe);
+MODULE_DESCRIPTION("Aspeed Serial GPIO Driver");
+MODULE_LICENSE("GPL");
--
2.7.4
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