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// 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),
};
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