--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2023 Andes Technology Corporation.
+ *
+ */
+
+#include <asm/io.h>
+#include <dm.h>
+#include <hang.h>
+#include <linux/bitops.h>
+#include <wdt.h>
+
+#define NODE_NOT_FOUND 0xFFFFFFFF
+
+#define WDT_WP_MAGIC 0x5aa5
+#define WDT_RESTART_MAGIC 0xcafe
+
+/* Control Register */
+#define REG_WDT_ID 0x00
+#define REG_WDT_CFG 0x10
+#define REG_WDT_RS 0x14
+#define REG_WDT_WE 0x18
+#define REG_WDT_STA 0x1C
+
+#define RST_TIME_OFF 8
+#define RST_TIME_MSK (0x7 << RST_TIME_OFF)
+#define RST_CLK_128 (0 << RST_TIME_OFF)
+#define RST_CLK_256 (1 << RST_TIME_OFF)
+#define RST_CLK_512 (2 << RST_TIME_OFF)
+#define RST_CLK_1024 (3 << RST_TIME_OFF)
+#define INT_TIME_OFF 4
+#define INT_TIME_MSK (0xf << INT_TIME_OFF)
+#define INT_CLK_2_6 (0 << INT_TIME_OFF) /* clk period*2^6 */
+#define INT_CLK_2_8 (1 << INT_TIME_OFF) /* clk period*2^8 */
+#define INT_CLK_2_10 (2 << INT_TIME_OFF) /* clk period*2^10 */
+#define INT_CLK_2_11 (3 << INT_TIME_OFF) /* clk period*2^11 */
+#define INT_CLK_2_12 (4 << INT_TIME_OFF) /* clk period*2^12 */
+#define INT_CLK_2_13 (5 << INT_TIME_OFF) /* clk period*2^13 */
+#define INT_CLK_2_14 (6 << INT_TIME_OFF) /* clk period*2^14 */
+#define INT_CLK_2_15 (7 << INT_TIME_OFF) /* clk period*2^15 */
+#define INT_CLK_2_17 (8 << INT_TIME_OFF) /* clk period*2^17 */
+#define INT_CLK_2_19 (9 << INT_TIME_OFF) /* clk period*2^19 */
+#define INT_CLK_2_21 (10 << INT_TIME_OFF) /* clk period*2^21 */
+#define INT_CLK_2_23 (11 << INT_TIME_OFF) /* clk period*2^23 */
+#define INT_CLK_2_25 (12 << INT_TIME_OFF) /* clk period*2^25 */
+#define INT_CLK_2_27 (13 << INT_TIME_OFF) /* clk period*2^27 */
+#define INT_CLK_2_29 (14 << INT_TIME_OFF) /* clk period*2^29 */
+#define INT_CLK_2_31 (15 << INT_TIME_OFF) /* clk period*2^31 */
+#define INT_CLK_MIN 0x0
+#define INT_CLK_MAX_16B 0x7
+#define INT_CLK_MAX_32B 0xF
+#define RST_EN BIT(3)
+#define INT_EN BIT(2)
+#define CLK_PCLK BIT(1)
+#define WDT_EN BIT(0)
+#define INT_EXPIRED BIT(0)
+
+#define INT_TIME_ARRAY 16
+#define RST_TIME_ARRAY 8
+
+struct wdt_priv {
+ void __iomem *base;
+ u32 wdt_clk_src;
+ u32 clk_freq;
+ u8 max_clk;
+};
+
+static inline u8 atcwdt_get_2_power_of_n(u8 index, u8 type)
+{
+ const u8 div_int[INT_TIME_ARRAY] = {6, 8, 10, 11, 12, 13, 14, 15,
+ 17, 19, 21, 23, 25, 27, 29, 31};
+ const u8 div_rst[RST_TIME_ARRAY] = {7, 8, 9, 10, 11, 12, 13, 14};
+ const u8 *pdiv;
+
+ if (type == RST_TIME_ARRAY)
+ pdiv = div_rst;
+ else
+ pdiv = div_int;
+
+ if (index >= type)
+ index = type - 1;
+
+ return pdiv[index];
+}
+
+static u8 atcwdt_search_msb(u64 freq_ms, u8 type)
+{
+ u64 result;
+ u64 freq_sec;
+ u8 index;
+
+ freq_sec = freq_ms / 1000;
+ for (index = 0; index < type; index++) {
+ result = freq_sec >> atcwdt_get_2_power_of_n(index, type);
+
+ if (result <= 1)
+ break;
+ }
+
+ return index;
+}
+
+static int atcwdt_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
+{
+ struct wdt_priv *priv = dev_get_priv(dev);
+ u64 rst_max_count;
+ u32 rst_max_time_ms;
+ u64 rst_time_ms;
+ u64 int_time_ms;
+ u8 rst_time;
+ u8 int_time;
+
+ rst_max_count = 1 << atcwdt_get_2_power_of_n(RST_TIME_ARRAY, RST_TIME_ARRAY);
+ rst_max_time_ms = (rst_max_count * 1000) / priv->clk_freq;
+
+ if (timeout > rst_max_time_ms) {
+ int_time_ms = timeout - rst_max_time_ms;
+ rst_time_ms = rst_max_time_ms;
+ } else {
+ int_time_ms = 0;
+ rst_time_ms = timeout;
+ }
+
+ rst_time = atcwdt_search_msb(rst_time_ms * priv->clk_freq, RST_TIME_ARRAY);
+
+ if (int_time_ms) {
+ int_time = atcwdt_search_msb(int_time_ms * priv->clk_freq, INT_TIME_ARRAY);
+ if (int_time > priv->max_clk)
+ int_time = priv->max_clk;
+ } else {
+ int_time = 0;
+ }
+
+ writel(WDT_WP_MAGIC, priv->base + REG_WDT_WE);
+ writel(((rst_time << RST_TIME_OFF) & RST_TIME_MSK) | ((int_time << INT_TIME_OFF) &
+ INT_TIME_MSK) | INT_EN | RST_EN | priv->wdt_clk_src | WDT_EN,
+ priv->base + REG_WDT_CFG);
+
+ return 0;
+}
+
+static int atcwdt_wdt_stop(struct udevice *dev)
+{
+ struct wdt_priv *priv = dev_get_priv(dev);
+
+ writel(WDT_WP_MAGIC, priv->base + REG_WDT_WE);
+ writel(0, priv->base + REG_WDT_CFG);
+
+ return 0;
+}
+
+static int atcwdt_wdt_restart(struct udevice *dev)
+{
+ struct wdt_priv *priv = dev_get_priv(dev);
+
+ writel(WDT_WP_MAGIC, priv->base + REG_WDT_WE);
+ writel(WDT_RESTART_MAGIC, priv->base + REG_WDT_RS);
+ setbits_le32(priv->base + REG_WDT_STA, INT_EXPIRED);
+
+ return 0;
+}
+
+static int atcwdt_wdt_expire_now(struct udevice *dev, ulong flags)
+{
+ atcwdt_wdt_start(dev, 0, 0);
+ hang();
+
+ return 0;
+}
+
+static int atcwdt_wdt_probe(struct udevice *dev)
+{
+ struct wdt_priv *priv = dev_get_priv(dev);
+ int timer_16bit;
+
+ priv->base = dev_remap_addr_index(dev, 0);
+ if (!priv->base)
+ return -EFAULT;
+
+ priv->wdt_clk_src = dev_read_u32_default(dev, "clock-source", NODE_NOT_FOUND);
+ if (priv->wdt_clk_src == NODE_NOT_FOUND || priv->wdt_clk_src > 1)
+ priv->wdt_clk_src = CLK_PCLK;
+
+ timer_16bit = dev_read_u32_default(dev, "16bit_timer", NODE_NOT_FOUND);
+ if (timer_16bit == 1 || timer_16bit == NODE_NOT_FOUND)
+ priv->max_clk = INT_CLK_MAX_16B;
+ else
+ priv->max_clk = INT_CLK_MAX_32B;
+
+ priv->clk_freq = dev_read_u32_default(dev, "clock-frequency", NODE_NOT_FOUND);
+ if (priv->clk_freq == NODE_NOT_FOUND) {
+ printf("atcwdt200: Please provide a valid \"clock-frequency\" in DTB\n");
+ return -EINVAL;
+ }
+
+ atcwdt_wdt_stop(dev);
+
+ return 0;
+}
+
+static const struct wdt_ops atcwdt_wdt_ops = {
+ .start = atcwdt_wdt_start,
+ .reset = atcwdt_wdt_restart,
+ .stop = atcwdt_wdt_stop,
+ .expire_now = atcwdt_wdt_expire_now,
+};
+
+static const struct udevice_id atcwdt_wdt_ids[] = {
+ {.compatible = "andestech,atcwdt200"},
+ {}
+};
+
+U_BOOT_DRIVER(atcwdt) = {
+ .name = "atcwdt200",
+ .id = UCLASS_WDT,
+ .probe = atcwdt_wdt_probe,
+ .of_match = atcwdt_wdt_ids,
+ .ops = &atcwdt_wdt_ops,
+ .priv_auto = sizeof(struct wdt_priv),
+};
projects / u-boot.git / commitdiff
