gpio: Add Aspeed GPIO driver

The Aspeed GPIO driver supports the GPIO controllers found in the
AST2400, AST2500 and AST2600 BMC SoCs. The implementation is a cut-down
copy of the upstream Linux kernel driver, adapted for u-boot.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>

1 files changed, 299 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-aspeed.c b/drivers/gpio/gpio-aspeed.c
new file mode 100644
index 00000000000..a8a2afcb5c8
--- /dev/null
+++ b/drivers/gpio/gpio-aspeed.c
@@ -0,0 +1,299 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2015 IBM Corp.
+ * Joel Stanley <joel@jms.id.au>
+ * Ryan Chen <ryan_chen@aspeedtech.com>
+ *
+ * Implementation extracted from the Linux kernel and adapted for u-boot.
+ */
+#include <common.h>
+#include <asm/io.h>
+#include <asm/gpio.h>
+
+#include <config.h>
+#include <common.h>
+#include <clk.h>
+#include <dm.h>
+#include <asm/io.h>
+#include <linux/bug.h>
+#include <linux/sizes.h>
+
+struct aspeed_gpio_priv {
+	void *regs;
+};
+
+struct aspeed_gpio_bank {
+	u16		val_regs;	/* +0: Rd: read input value, Wr: set write latch
+					 * +4: Rd/Wr: Direction (0=in, 1=out)
+					 */
+	u16		rdata_reg;	/*     Rd: read write latch, Wr: <none>  */
+	u16		irq_regs;
+	u16		debounce_regs;
+	u16		tolerance_regs;
+	u16		cmdsrc_regs;
+	const char	names[4][3];
+};
+
+static const struct aspeed_gpio_bank aspeed_gpio_banks[] = {
+	{
+		.val_regs = 0x0000,
+		.rdata_reg = 0x00c0,
+		.irq_regs = 0x0008,
+		.debounce_regs = 0x0040,
+		.tolerance_regs = 0x001c,
+		.cmdsrc_regs = 0x0060,
+		.names = { "A", "B", "C", "D" },
+	},
+	{
+		.val_regs = 0x0020,
+		.rdata_reg = 0x00c4,
+		.irq_regs = 0x0028,
+		.debounce_regs = 0x0048,
+		.tolerance_regs = 0x003c,
+		.cmdsrc_regs = 0x0068,
+		.names = { "E", "F", "G", "H" },
+	},
+	{
+		.val_regs = 0x0070,
+		.rdata_reg = 0x00c8,
+		.irq_regs = 0x0098,
+		.debounce_regs = 0x00b0,
+		.tolerance_regs = 0x00ac,
+		.cmdsrc_regs = 0x0090,
+		.names = { "I", "J", "K", "L" },
+	},
+	{
+		.val_regs = 0x0078,
+		.rdata_reg = 0x00cc,
+		.irq_regs = 0x00e8,
+		.debounce_regs = 0x0100,
+		.tolerance_regs = 0x00fc,
+		.cmdsrc_regs = 0x00e0,
+		.names = { "M", "N", "O", "P" },
+	},
+	{
+		.val_regs = 0x0080,
+		.rdata_reg = 0x00d0,
+		.irq_regs = 0x0118,
+		.debounce_regs = 0x0130,
+		.tolerance_regs = 0x012c,
+		.cmdsrc_regs = 0x0110,
+		.names = { "Q", "R", "S", "T" },
+	},
+	{
+		.val_regs = 0x0088,
+		.rdata_reg = 0x00d4,
+		.irq_regs = 0x0148,
+		.debounce_regs = 0x0160,
+		.tolerance_regs = 0x015c,
+		.cmdsrc_regs = 0x0140,
+		.names = { "U", "V", "W", "X" },
+	},
+	{
+		.val_regs = 0x01E0,
+		.rdata_reg = 0x00d8,
+		.irq_regs = 0x0178,
+		.debounce_regs = 0x0190,
+		.tolerance_regs = 0x018c,
+		.cmdsrc_regs = 0x0170,
+		.names = { "Y", "Z", "AA", "AB" },
+	},
+	{
+		.val_regs = 0x01e8,
+		.rdata_reg = 0x00dc,
+		.irq_regs = 0x01a8,
+		.debounce_regs = 0x01c0,
+		.tolerance_regs = 0x01bc,
+		.cmdsrc_regs = 0x01a0,
+		.names = { "AC", "", "", "" },
+	},
+};
+
+enum aspeed_gpio_reg {
+	reg_val,
+	reg_rdata,
+	reg_dir,
+	reg_irq_enable,
+	reg_irq_type0,
+	reg_irq_type1,
+	reg_irq_type2,
+	reg_irq_status,
+	reg_debounce_sel1,
+	reg_debounce_sel2,
+	reg_tolerance,
+	reg_cmdsrc0,
+	reg_cmdsrc1,
+};
+
+#define GPIO_VAL_VALUE	0x00
+#define GPIO_VAL_DIR	0x04
+
+#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
+
+#define GPIO_DEBOUNCE_SEL1 0x00
+#define GPIO_DEBOUNCE_SEL2 0x04
+
+#define GPIO_CMDSRC_0	0x00
+#define GPIO_CMDSRC_1	0x04
+#define  GPIO_CMDSRC_ARM		0
+#define  GPIO_CMDSRC_LPC		1
+#define  GPIO_CMDSRC_COLDFIRE		2
+#define  GPIO_CMDSRC_RESERVED		3
+
+/* This will be resolved at compile time */
+static inline void __iomem *bank_reg(struct aspeed_gpio_priv *gpio,
+				     const struct aspeed_gpio_bank *bank,
+				     const enum aspeed_gpio_reg reg)
+{
+	switch (reg) {
+	case reg_val:
+		return gpio->regs + bank->val_regs + GPIO_VAL_VALUE;
+	case reg_rdata:
+		return gpio->regs + bank->rdata_reg;
+	case reg_dir:
+		return gpio->regs + bank->val_regs + GPIO_VAL_DIR;
+	case reg_irq_enable:
+		return gpio->regs + bank->irq_regs + GPIO_IRQ_ENABLE;
+	case reg_irq_type0:
+		return gpio->regs + bank->irq_regs + GPIO_IRQ_TYPE0;
+	case reg_irq_type1:
+		return gpio->regs + bank->irq_regs + GPIO_IRQ_TYPE1;
+	case reg_irq_type2:
+		return gpio->regs + bank->irq_regs + GPIO_IRQ_TYPE2;
+	case reg_irq_status:
+		return gpio->regs + bank->irq_regs + GPIO_IRQ_STATUS;
+	case reg_debounce_sel1:
+		return gpio->regs + bank->debounce_regs + GPIO_DEBOUNCE_SEL1;
+	case reg_debounce_sel2:
+		return gpio->regs + bank->debounce_regs + GPIO_DEBOUNCE_SEL2;
+	case reg_tolerance:
+		return gpio->regs + bank->tolerance_regs;
+	case reg_cmdsrc0:
+		return gpio->regs + bank->cmdsrc_regs + GPIO_CMDSRC_0;
+	case reg_cmdsrc1:
+		return gpio->regs + bank->cmdsrc_regs + GPIO_CMDSRC_1;
+	}
+	BUG();
+}
+
+#define GPIO_BANK(x)	((x) >> 5)
+#define GPIO_OFFSET(x)	((x) & 0x1f)
+#define GPIO_BIT(x)	BIT(GPIO_OFFSET(x))
+
+static const struct aspeed_gpio_bank *to_bank(unsigned int offset)
+{
+	unsigned int bank = GPIO_BANK(offset);
+
+	WARN_ON(bank >= ARRAY_SIZE(aspeed_gpio_banks));
+	return &aspeed_gpio_banks[bank];
+}
+
+static int
+aspeed_gpio_direction_input(struct udevice *dev, unsigned int offset)
+{
+	struct aspeed_gpio_priv *priv = dev_get_priv(dev);
+	const struct aspeed_gpio_bank *bank = to_bank(offset);
+	u32 dir = readl(bank_reg(priv, bank, reg_dir));
+
+	dir &= ~GPIO_BIT(offset);
+	writel(dir, bank_reg(priv, bank, reg_dir));
+
+	return 0;
+}
+
+static int aspeed_gpio_direction_output(struct udevice *dev, unsigned int offset,
+					int value)
+{
+	struct aspeed_gpio_priv *priv = dev_get_priv(dev);
+	const struct aspeed_gpio_bank *bank = to_bank(offset);
+	u32 dir = readl(bank_reg(priv, bank, reg_dir));
+	u32 output = readl(bank_reg(priv, bank, reg_val));
+
+	dir |= GPIO_BIT(offset);
+	writel(dir, bank_reg(priv, bank, reg_dir));
+
+	if (value)
+		output |= GPIO_BIT(offset);
+	else
+		output &= ~GPIO_BIT(offset);
+
+	writel(output, bank_reg(priv, bank, reg_val));
+
+	return 0;
+}
+
+static int aspeed_gpio_get_value(struct udevice *dev, unsigned int offset)
+{
+	struct aspeed_gpio_priv *priv = dev_get_priv(dev);
+	const struct aspeed_gpio_bank *bank = to_bank(offset);
+
+	return !!(readl(bank_reg(priv, bank, reg_val)) & GPIO_BIT(offset));
+}
+
+static int
+aspeed_gpio_set_value(struct udevice *dev, unsigned int offset, int value)
+{
+	struct aspeed_gpio_priv *priv = dev_get_priv(dev);
+	const struct aspeed_gpio_bank *bank = to_bank(offset);
+	u32 data = readl(bank_reg(priv, bank, reg_val));
+
+	if (value)
+		data |= GPIO_BIT(offset);
+	else
+		data &= ~GPIO_BIT(offset);
+
+	writel(data, bank_reg(priv, bank, reg_val));
+
+	return 0;
+}
+
+static int aspeed_gpio_get_function(struct udevice *dev, unsigned int offset)
+{
+	struct aspeed_gpio_priv *priv = dev_get_priv(dev);
+	const struct aspeed_gpio_bank *bank = to_bank(offset);
+
+	if (readl(bank_reg(priv, bank, reg_dir)) & GPIO_BIT(offset))
+		return GPIOF_OUTPUT;
+
+	return GPIOF_INPUT;
+}
+
+static const struct dm_gpio_ops aspeed_gpio_ops = {
+	.direction_input	= aspeed_gpio_direction_input,
+	.direction_output	= aspeed_gpio_direction_output,
+	.get_value		= aspeed_gpio_get_value,
+	.set_value		= aspeed_gpio_set_value,
+	.get_function		= aspeed_gpio_get_function,
+};
+
+static int aspeed_gpio_probe(struct udevice *dev)
+{
+	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+	struct aspeed_gpio_priv *priv = dev_get_priv(dev);
+
+	uc_priv->bank_name = dev->name;
+	ofnode_read_u32(dev_ofnode(dev), "ngpios", &uc_priv->gpio_count);
+	priv->regs = devfdt_get_addr_ptr(dev);
+
+	return 0;
+}
+
+static const struct udevice_id aspeed_gpio_ids[] = {
+	{ .compatible = "aspeed,ast2400-gpio",  },
+	{ .compatible = "aspeed,ast2500-gpio",	},
+	{ .compatible = "aspeed,ast2600-gpio",	},
+	{ }
+};
+
+U_BOOT_DRIVER(gpio_aspeed) = {
+	.name   = "gpio-aspeed",
+	.id     = UCLASS_GPIO,
+	.of_match = aspeed_gpio_ids,
+	.ops    = &aspeed_gpio_ops,
+	.probe  = aspeed_gpio_probe,
+	.priv_auto = sizeof(struct aspeed_gpio_priv),
+};