From 9bb68d8820480519e8b331f7a8b866b8718ad7fd Mon Sep 17 00:00:00 2001
From: Alexander Filippov <a.filippov@yadro.com>
Date: Tue, 19 May 2020 18:55:41 +0300
Subject: [PATCH] aspeed: add gpio support

This is an initial support for the parallel GPIO pins directly connected
to the AHB on the Aspeed 2400/2500.

This brings the functions and a shell command to manipulate the GPIO
state. The GPIO value reading and writing work in non interrupt mode
only.

Signed-off-by: Alexander Filippov <a.filippov@yadro.com>
---
 arch/arm/include/asm/arch-aspeed/gpio.h     |  65 ++++
 arch/arm/include/asm/arch-aspeed/platform.h |   1 +
 drivers/gpio/Makefile                       |   2 +
 drivers/gpio/aspeed_gpio.c                  | 386 ++++++++++++++++++++
 4 files changed, 454 insertions(+)
 create mode 100644 arch/arm/include/asm/arch-aspeed/gpio.h
 create mode 100644 drivers/gpio/aspeed_gpio.c

diff --git a/arch/arm/include/asm/arch-aspeed/gpio.h b/arch/arm/include/asm/arch-aspeed/gpio.h
new file mode 100644
index 0000000000..c63987e917
--- /dev/null
+++ b/arch/arm/include/asm/arch-aspeed/gpio.h
@@ -0,0 +1,65 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0+
+ * Copyright (C) 2020 YADRO.
+ */
+#ifndef _ASPEED_GPIO_H
+#define _ASPEED_GPIO_H
+
+#define ASPEED_GPIO_PORT_A 0
+#define ASPEED_GPIO_PORT_B 1
+#define ASPEED_GPIO_PORT_C 2
+#define ASPEED_GPIO_PORT_D 3
+#define ASPEED_GPIO_PORT_E 4
+#define ASPEED_GPIO_PORT_F 5
+#define ASPEED_GPIO_PORT_G 6
+#define ASPEED_GPIO_PORT_H 7
+#define ASPEED_GPIO_PORT_I 8
+#define ASPEED_GPIO_PORT_J 9
+#define ASPEED_GPIO_PORT_K 10
+#define ASPEED_GPIO_PORT_L 11
+#define ASPEED_GPIO_PORT_M 12
+#define ASPEED_GPIO_PORT_N 13
+#define ASPEED_GPIO_PORT_O 14
+#define ASPEED_GPIO_PORT_P 15
+#define ASPEED_GPIO_PORT_Q 16
+#define ASPEED_GPIO_PORT_R 17
+#define ASPEED_GPIO_PORT_S 18
+#define ASPEED_GPIO_PORT_T 19
+#define ASPEED_GPIO_PORT_U 20
+#define ASPEED_GPIO_PORT_V 21
+#define ASPEED_GPIO_PORT_W 22
+#define ASPEED_GPIO_PORT_X 23
+#define ASPEED_GPIO_PORT_Y 24
+#define ASPEED_GPIO_PORT_Z 25
+#define ASPEED_GPIO_PORT_AA 26
+#define ASPEED_GPIO_PORT_AB 27
+#define ASPEED_GPIO_PORT_AC 28
+
+#define ASPEED_GPIO_PORT_SHIFT 3
+#define ASPEED_GPIO_PIN_MASK 0x7
+#define ASPEED_GPIO(port, pin)                                                 \
+    ((ASPEED_GPIO_PORT_##port << ASPEED_GPIO_PORT_SHIFT) |                     \
+     (pin & ASPEED_GPIO_PIN_MASK))
+
+/* Direction values */
+#define ASPEED_GPIO_INPUT 0
+#define ASPEED_GPIO_OUTPUT 1
+
+/* Trigger values */
+#define ASPEED_GPIO_FALLING_EDGE 0
+#define ASPEED_GPIO_RISING_EDGE 1
+#define ASPEED_GPIO_LOW_LEVEL 2
+#define ASPEED_GPIO_HIGH_LEVEL 3
+#define ASPEED_GPIO_DUAL_EDGE 4
+
+/* Debounce values */
+#define ASPEED_GPIO_DEBOUNCE_NONE 0
+#define ASPEED_GPIO_DEBOUNCE_1 1
+#define ASPEED_GPIO_DEBOUNCE_2 2
+#define ASPEED_GPIO_DEBOUNCE_3 3
+
+#define gpio_status() gpio_info()
+
+extern void gpio_info(void);
+
+#endif /* #ifndef _ASPEED_GPIO_H */
diff --git a/arch/arm/include/asm/arch-aspeed/platform.h b/arch/arm/include/asm/arch-aspeed/platform.h
index b9207c492f..0a05a7a7a0 100644
--- a/arch/arm/include/asm/arch-aspeed/platform.h
+++ b/arch/arm/include/asm/arch-aspeed/platform.h
@@ -32,5 +32,6 @@
 #endif
 
 #define CONFIG_BOARD_LATE_INIT 1 /* Call board_late_init */
+#define CONFIG_CMD_GPIO 1        /* Enable gpio command in shell */
 
 #endif
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 792d19186a..5f043e07ce 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -14,6 +14,8 @@ obj-$(CONFIG_DM_GPIO)		+= gpio-uclass.o
 obj-$(CONFIG_DM_PCA953X)	+= pca953x_gpio.o
 obj-$(CONFIG_DM_74X164)		+= 74x164_gpio.o
 
+obj-$(CONFIG_ARCH_AST2400)	+= aspeed_gpio.o
+obj-$(CONFIG_ARCH_AST2500)	+= aspeed_gpio.o
 obj-$(CONFIG_AT91_GPIO)	+= at91_gpio.o
 obj-$(CONFIG_ATMEL_PIO4)	+= atmel_pio4.o
 obj-$(CONFIG_INTEL_ICH6_GPIO)	+= intel_ich6_gpio.o
diff --git a/drivers/gpio/aspeed_gpio.c b/drivers/gpio/aspeed_gpio.c
new file mode 100644
index 0000000000..dc07f5a520
--- /dev/null
+++ b/drivers/gpio/aspeed_gpio.c
@@ -0,0 +1,386 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0+
+ * Copyright (C) 2020 YADRO.
+ */
+
+#include <common.h>
+
+#include <asm/arch/gpio.h>
+#include <asm/arch/platform.h>
+#include <asm/io.h>
+#include <linux/ctype.h>
+
+typedef struct _ast_gpio_regs
+{
+    uint32_t base;     /* data and direction registers */
+    uint32_t intcfg;   /* interrupt config */
+    uint32_t debounce; /* debounce config */
+    uint32_t cmdsrc;   /* command source config */
+    uint32_t data;     /* data read register */
+} ast_gpio_regs_t;
+
+static ast_gpio_regs_t ast_gpio_regs[] = {
+    /* A/B/C/D */
+    {AST_GPIO_BASE + 0x0000, AST_GPIO_BASE + 0x0008, AST_GPIO_BASE + 0x0040,
+     AST_GPIO_BASE + 0x0060, AST_GPIO_BASE + 0x00C0},
+    /* E/F/G/H */
+    {AST_GPIO_BASE + 0x0020, AST_GPIO_BASE + 0x0028, AST_GPIO_BASE + 0x0048,
+     AST_GPIO_BASE + 0x0068, AST_GPIO_BASE + 0x00C4},
+    /* I/J/K/L */
+    {AST_GPIO_BASE + 0x0070, AST_GPIO_BASE + 0x0098, AST_GPIO_BASE + 0x00B0,
+     AST_GPIO_BASE + 0x0090, AST_GPIO_BASE + 0x00C8},
+    /* M/N/O/P */
+    {AST_GPIO_BASE + 0x0078, AST_GPIO_BASE + 0x00E8, AST_GPIO_BASE + 0x0100,
+     AST_GPIO_BASE + 0x00E0, AST_GPIO_BASE + 0x00CC},
+    /* Q/R/S/T */
+    {AST_GPIO_BASE + 0x0080, AST_GPIO_BASE + 0x0118, AST_GPIO_BASE + 0x0130,
+     AST_GPIO_BASE + 0x0110, AST_GPIO_BASE + 0x00D0},
+    /* U/V/W/X */
+    {AST_GPIO_BASE + 0x0088, AST_GPIO_BASE + 0x0148, AST_GPIO_BASE + 0x0160,
+     AST_GPIO_BASE + 0x0140, AST_GPIO_BASE + 0x00D4},
+    /* Y/Z/AA/AB */
+    {AST_GPIO_BASE + 0x01E0, AST_GPIO_BASE + 0x0178, AST_GPIO_BASE + 0x0190,
+     AST_GPIO_BASE + 0x0170, AST_GPIO_BASE + 0x00D8},
+    /* AC */
+    {AST_GPIO_BASE + 0x01E8, AST_GPIO_BASE + 0x01A8, AST_GPIO_BASE + 0x01C0,
+     AST_GPIO_BASE + 0x01A0, AST_GPIO_BASE + 0x00DC},
+};
+
+#define AST_GPIO_PINS_PER_PORT 8
+#define AST_GPIO_PORTS_PER_REGISTER 4
+
+#define AST_GPIO_PORT(gpio) (gpio >> ASPEED_GPIO_PORT_SHIFT)
+#define AST_GPIO_PIN(gpio) (gpio & ASPEED_GPIO_PIN_MASK)
+#define AST_GPIO_SHIFT(gpio)                                                   \
+    ((AST_GPIO_PORT(gpio) % AST_GPIO_PORTS_PER_REGISTER) *                     \
+         AST_GPIO_PINS_PER_PORT +                                              \
+     AST_GPIO_PIN(gpio))
+
+#define AST_GPIO_REG_INDEX(gpio)                                               \
+    (AST_GPIO_PORT(gpio) / AST_GPIO_PORTS_PER_REGISTER)
+
+/**
+ * @return Pointer to corresponding item from ast_gpio_regs table.
+ */
+#define AST_GPIO_REGS(gpio)                                                    \
+    ((AST_GPIO_REG_INDEX(gpio) < ARRAY_SIZE(ast_gpio_regs))                    \
+         ? (ast_gpio_regs + AST_GPIO_REG_INDEX(gpio))                          \
+         : NULL)
+
+/**
+ * @brief Set a corresponding bit in specified register.
+ *
+ * @param val - Required bit value
+ * @param base - Register address
+ * @param shift - Bit index.
+ */
+#define AST_GPIO_WRITE(val, base, shift)                                       \
+    writel(((val) ? readl(base) | (1 << (shift))                               \
+                  : readl(base) & ~(1 << (shift))),                            \
+           base)
+
+/**
+ * @brief Get value of corresponging bit from specified register.
+ *
+ * @param base - Register address
+ * @param shift - Bit index
+ *
+ * @return Bit value
+ */
+#define AST_GPIO_READ(base, shift) ((readl(base) >> (shift)) & 1)
+
+#define IS_VALID_GPIO(gpio)                                                    \
+    ((gpio) >= ASPEED_GPIO(A, 0) && (gpio) <= ASPEED_GPIO(AC, 7))
+
+#define AST_GPIO_DIRECTION 0x04
+#define AST_GPIO_INT_SENS0 0x04
+#define AST_GPIO_INT_SENS1 0x08
+#define AST_GPIO_INT_SENS2 0x0C
+#define AST_GPIO_INT_STATUS 0x10
+#define AST_GPIO_DEBOUNCE0 0x00
+#define AST_GPIO_DEBOUNCE1 0x04
+#define AST_GPIO_CMD_SRC0 0x00
+#define AST_GPIO_CMD_SRC1 0x04
+
+/**
+ * @brief Set a GPIO direction
+ *
+ * @param gpio      GPIO line
+ * @param direction GPIO direction (0 for input or 1 for output)
+ *
+ * @return 0 if ok, -1 on error
+ */
+static int ast_gpio_set_direction(unsigned gpio, unsigned direction)
+{
+    ast_gpio_regs_t *regs = AST_GPIO_REGS(gpio);
+    if (!regs)
+    {
+        printf("%s: Invalid GPIO!\n", __func__);
+        return -1;
+    }
+
+    AST_GPIO_WRITE(direction, regs->base + AST_GPIO_DIRECTION,
+                   AST_GPIO_SHIFT(gpio));
+    return 0;
+}
+
+/**
+ * The 6 following functions are generic u-boot gpio implementation.
+ * They are declared in `include/asm-generic/gpio.h`
+ */
+
+int gpio_request(unsigned gpio, const char *label)
+{
+    return (IS_VALID_GPIO(gpio) ? 0 : -1);
+}
+
+int gpio_free(unsigned gpio)
+{
+    return (IS_VALID_GPIO(gpio) ? 0 : -1);
+}
+
+int gpio_get_value(unsigned gpio)
+{
+    ast_gpio_regs_t *regs = AST_GPIO_REGS(gpio);
+    if (!regs)
+    {
+        printf("%s: Invalid GPIO!\n", __func__);
+        return -1;
+    }
+
+    return AST_GPIO_READ(regs->base, AST_GPIO_SHIFT(gpio));
+}
+
+int gpio_set_value(unsigned gpio, int value)
+{
+    ast_gpio_regs_t *regs = AST_GPIO_REGS(gpio);
+    if (!regs)
+    {
+        printf("%s: Invalid GPIO!\n", __func__);
+        return -1;
+    }
+
+    AST_GPIO_WRITE(value, regs->base, AST_GPIO_SHIFT(gpio));
+    return 0;
+}
+
+int gpio_direction_input(unsigned gpio)
+{
+    return ast_gpio_set_direction(gpio, ASPEED_GPIO_INPUT);
+}
+
+int gpio_direction_output(unsigned gpio, int value)
+{
+    int rc = ast_gpio_set_direction(gpio, ASPEED_GPIO_OUTPUT);
+    return (rc == 0 ? gpio_set_value(gpio, value) : rc);
+}
+
+/**
+ * @brief Convert a string to GPIO line. Used by `do_gpio()` from `cmd/gpio.c`
+ *
+ * @param str a GPIO name or line number
+ *
+ * @return GPIO line if ok, -1 on error
+ */
+int name_to_gpio(const char *str)
+{
+    int gpio = -1;
+
+    if (str)
+    {
+        if (isalpha(*str))
+        {
+            gpio = (toupper(*str) - 'A') << ASPEED_GPIO_PORT_SHIFT;
+
+            if (toupper(*str) == 'A' && toupper(*(str + 1)) >= 'A' &&
+                toupper(*(str + 1)) <= 'C')
+            {
+                str++;
+                gpio = (ASPEED_GPIO_PORT_AA + toupper(*str) - 'A')
+                       << ASPEED_GPIO_PORT_SHIFT;
+            }
+
+            str++;
+            if (*str >= '0' && *str <= '7' && !*(str + 1))
+            {
+                gpio += *str - '0';
+            }
+            else
+            {
+                gpio = -1;
+            }
+        }
+        else if (isdigit(*str))
+        {
+            gpio = simple_strtoul(str, NULL, 0);
+        }
+    }
+
+    return gpio;
+}
+
+/**
+ * @return A GPIO direction in human readable format.
+ */
+static const char *ast_gpio_direction(unsigned gpio)
+{
+    ast_gpio_regs_t *regs = AST_GPIO_REGS(gpio);
+    if (regs)
+    {
+        int direction = AST_GPIO_READ(regs->base + AST_GPIO_DIRECTION,
+                                      AST_GPIO_SHIFT(gpio));
+        switch (direction)
+        {
+            case ASPEED_GPIO_INPUT:
+                return "input";
+            case ASPEED_GPIO_OUTPUT:
+                return "output";
+            default:
+                break;
+        }
+    }
+    return "error";
+}
+
+/**
+ * @return An interrupt trigger settings in human readable format.
+ */
+static const char *ast_gpio_trigger(unsigned gpio)
+{
+    ast_gpio_regs_t *regs = AST_GPIO_REGS(gpio);
+    if (regs)
+    {
+        unsigned shift = AST_GPIO_SHIFT(gpio);
+        unsigned trigger =
+            (AST_GPIO_READ(regs->intcfg + AST_GPIO_INT_SENS0, shift) << 0) |
+            (AST_GPIO_READ(regs->intcfg + AST_GPIO_INT_SENS1, shift) << 1) |
+            (AST_GPIO_READ(regs->intcfg + AST_GPIO_INT_SENS2, shift) << 2);
+
+        switch (trigger)
+        {
+            case ASPEED_GPIO_FALLING_EDGE:
+                return "fall";
+            case ASPEED_GPIO_RISING_EDGE:
+                return "rise";
+            case ASPEED_GPIO_LOW_LEVEL:
+                return "low ";
+            case ASPEED_GPIO_HIGH_LEVEL:
+                return "high";
+            default:
+                return "both";
+        }
+    }
+    return "error";
+}
+
+/**
+ * @return An interrupt status in human readable format.
+ */
+static const char *ast_gpio_int_status(unsigned gpio)
+{
+    ast_gpio_regs_t *regs = AST_GPIO_REGS(gpio);
+    if (regs)
+    {
+        unsigned shift = AST_GPIO_SHIFT(gpio);
+        if (AST_GPIO_READ(regs->intcfg, shift))
+        {
+            return AST_GPIO_READ(regs->intcfg + AST_GPIO_INT_STATUS, shift)
+                       ? "pending"
+                       : "cleaned";
+        }
+        return "disabled";
+    }
+
+    return "error";
+}
+
+/**
+ * @return A debounce value in human readable format.
+ */
+static const char *ast_gpio_debounce(unsigned gpio)
+{
+    ast_gpio_regs_t *regs = AST_GPIO_REGS(gpio);
+    if (regs)
+    {
+        unsigned shift = AST_GPIO_SHIFT(gpio);
+        unsigned debounce =
+            (AST_GPIO_READ(regs->debounce + AST_GPIO_DEBOUNCE0, shift) << 0) |
+            (AST_GPIO_READ(regs->debounce + AST_GPIO_DEBOUNCE1, shift) << 1);
+        switch (debounce)
+        {
+            case ASPEED_GPIO_DEBOUNCE_NONE:
+                return "none";
+            case ASPEED_GPIO_DEBOUNCE_1:
+                return "timer1";
+            case ASPEED_GPIO_DEBOUNCE_2:
+                return "timer2";
+            case ASPEED_GPIO_DEBOUNCE_3:
+                return "timer3";
+            default:
+                break;
+        }
+    }
+
+    return "error";
+}
+
+/**
+ * @return A command source value in human readable format.
+ */
+static const char *ast_gpio_command_source(unsigned gpio)
+{
+    ast_gpio_regs_t *regs = AST_GPIO_REGS(gpio);
+    if (regs)
+    {
+        /* Used one bit per gpio port */
+        unsigned shift = AST_GPIO_SHIFT(gpio) - AST_GPIO_PIN(gpio);
+        unsigned cmdsrc =
+            (AST_GPIO_READ(regs->cmdsrc + AST_GPIO_CMD_SRC0, shift) << 0) |
+            (AST_GPIO_READ(regs->cmdsrc + AST_GPIO_CMD_SRC1, shift) << 1);
+
+        switch (cmdsrc)
+        {
+            /* The single place where these values are used is here. */
+            case 0x0:
+                return "ARM";
+            case 0x1:
+                return "LPC";
+            case 0x2:
+                return "CoCPU";
+            default:
+                return "Unknown";
+        }
+    }
+
+    return "error";
+}
+
+/**
+ * @brief Show all GPIO pins statuses. Used by `do_gpio()` in `cmd/gpio.c`
+ */
+void gpio_info(void)
+{
+    unsigned first = ASPEED_GPIO(A, 0);
+    unsigned last = ASPEED_GPIO(AC, 7);
+    for (unsigned gpio = first; gpio <= last; gpio++)
+    {
+        unsigned port = AST_GPIO_PORT(gpio);
+        unsigned pin = AST_GPIO_PIN(gpio);
+        unsigned shift = AST_GPIO_SHIFT(gpio);
+        ast_gpio_regs_t *regs = AST_GPIO_REGS(gpio);
+        if (!regs)
+        {
+            printf("gpio %u is invalid!\n", gpio);
+            continue;
+        }
+
+        printf("gpio %c%c%c line %3d: %s, int: %s, %s, deb: %s, src: %s, "
+               "val: %d/%d\n",
+               (port >= ASPEED_GPIO_PORT_AA ? 'A' : ' '),
+               ('A' + port % ASPEED_GPIO_PORT_AA), ('0' + pin), gpio,
+               ast_gpio_direction(gpio), ast_gpio_trigger(gpio),
+               ast_gpio_int_status(gpio), ast_gpio_debounce(gpio),
+               ast_gpio_command_source(gpio), gpio_get_value(gpio),
+               AST_GPIO_READ(regs->data, shift));
+    }
+}
-- 
2.25.4