linux-kernel - [PATCH 2/5] watchdog: eiois200_wdt: Add PMC support with eiois200

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Message-Id: <a3e22f8ebd9154e4fd4e11aef253de762e0523cf.1696495372.git.advantech.susiteam@gmail.com>
Date:   Thu,  5 Oct 2023 16:51:20 +0800
From:   advantech.susiteam@...il.com
To:     advantech.susiteam@...il.com
Cc:     wenkai.chung@...antech.com.tw, Susi.Driver@...antech.com,
        Wim Van Sebroeck <wim@...ux-watchdog.org>,
        Guenter Roeck <linux@...ck-us.net>,
        linux-kernel@...r.kernel.org, linux-watchdog@...r.kernel.org
Subject: [PATCH 2/5] watchdog: eiois200_wdt: Add PMC support with eiois200_core.

From: Wenkai <advantech.susiteam@...il.com>

All eiois200 series driver functionalities are based on PMC (Peripheral
Management Controller) communication. This patch enables communication
between the driver and the eiois200_core. However, this version does
not yet implement the watchdog timer's functionality.

Signed-off-by: Wenkai <advantech.susiteam@...il.com>
---
 drivers/watchdog/eiois200_wdt.c | 114 ++++++++++++++++++++++++++++++++
 1 file changed, 114 insertions(+)

diff --git a/drivers/watchdog/eiois200_wdt.c b/drivers/watchdog/eiois200_wdt.c
index bf132a75a2ec..ce4435ac62f2 100644
--- a/drivers/watchdog/eiois200_wdt.c
+++ b/drivers/watchdog/eiois200_wdt.c
@@ -16,6 +16,40 @@
 #define WATCHDOG_TIMEOUT	60
 #define WATCHDOG_PRETIMEOUT	10
 
+/* Support Flags */
+#define SUPPORT_AVAILABLE	BIT(0)
+#define SUPPORT_RESET		BIT(7)
+
+/* PMC registers */
+#define REG_STATUS		0x00
+#define REG_CONTROL		0x02
+#define REG_EVENT		0x10
+#define REG_RESET_EVENT_TIME	0x14
+#define REG_IRQ_NUMBER		0x17
+
+/* PMC command and control */
+#define CMD_WDT_WRITE		0x2A
+#define CMD_WDT_READ		0x2B
+#define CTRL_STOP		0x00
+#define CTRL_START		0x01
+#define CTRL_TRIGGER		0x02
+
+/* I/O register and its flags */
+#define IOREG_UNLOCK		0x87
+#define IOREG_LOCK		0xAA
+#define IOREG_LDN		0x07
+#define IOREG_LDN_PMCIO		0x0F
+#define IOREG_IRQ		0x70
+#define IOREG_WDT_STATUS	0x30
+
+/* Flags */
+#define FLAG_WDT_ENABLED	0x01
+#define FLAG_TRIGGER_IRQ	BIT(4)
+
+/* PMC read and write a value */
+#define PMC_WRITE(cmd, data)	pmc(CMD_WDT_WRITE, cmd, data)
+#define PMC_READ(cmd, data)	pmc(CMD_WDT_READ, cmd, data)
+
 static struct _wdt {
 	u32	support;
 	long	last_time;
@@ -47,6 +81,48 @@ static int wdt_set_timeout(struct watchdog_device *dev,
 	return 0;
 }
 
+static int pmc(u8 cmd, u8 ctrl, void *payload)
+{
+	struct pmc_op op = {
+		.cmd      = cmd,
+		.control  = ctrl,
+		.size     = ctrl <= REG_EVENT	   ? 1 :
+			    ctrl >= REG_IRQ_NUMBER ? 1 : 4,
+		.payload  = payload,
+	};
+
+	return eiois200_core_pmc_operation(wdt.dev, &op);
+}
+
+static int get_time(u8 ctrl, u32 *val)
+{
+	int ret;
+
+	ret = PMC_READ(ctrl, val);
+
+	/* ms to sec */
+	*val /= 1000;
+
+	return ret;
+}
+
+
+static int wdt_get_config(void)
+{
+	int ret;
+	u32 reset_time;
+
+	/* Get Reset Time */
+	ret = get_time(REG_RESET_EVENT_TIME, &reset_time);
+	if (ret)
+		return ret;
+
+	dev_info(wdt.dev, "Timeout H/W default timeout: %d secs\n", reset_time);
+	wddev.timeout	 = reset_time;
+
+	return 0;
+}
+
 static int wdt_start(struct watchdog_device *dev)
 {
 	return 0;
@@ -67,6 +143,40 @@ static unsigned int wdt_get_timeleft(struct watchdog_device *dev)
 	return 0;
 }
 
+static int wdt_support(void)
+{
+	u8 support;
+
+	if (PMC_READ(REG_STATUS, &support))
+		return -EIO;
+
+	if ((support & SUPPORT_AVAILABLE) == 0)
+		return -EIO;
+
+	/* Must support reset */
+	if ((support & SUPPORT_RESET) != SUPPORT_RESET)
+		return -EIO;
+
+	/* Must has support event **/
+	wdt.support = support;
+
+	return 0;
+}
+static int wdt_init(struct device *dev)
+{
+	int ret = 0;
+
+	ret = wdt_support();
+	if (ret)
+		return ret;
+
+	ret = wdt_get_config();
+	if (ret)
+		return ret;
+
+	return ret;
+}
+
 static const struct watchdog_ops wdt_ops = {
 	.owner		= THIS_MODULE,
 	.start		= wdt_start,
@@ -91,6 +201,10 @@ static int wdt_probe(struct platform_device *pdev)
 	wdt.iomap = dev_get_regmap(dev->parent, NULL);
 	if (!wdt.iomap)
 		return dev_err_probe(dev, -ENOMEM, "Query parent regmap fail\n");
+	
+	/* Initialize EC watchdog */
+	if (wdt_init(dev))
+		return dev_err_probe(dev, -EIO, "wdt_init fail\n");
 
 	/* Inform watchdog info */
 	wddev.ops = &wdt_ops;
-- 
2.34.1