[U-Boot] [PATCH v4] watchdog: Convert Xilinx Axi watchdog driver to driver model

[Michal Simek]

From: Shreenidhi Shedi <yesshedi at gmail.com>

Xilinx Axi wdt driver conversion to driver model & Kconfig update
for the same.

Signed-off-by: Shreenidhi Shedi <yesshedi at gmail.com>
Signed-off-by: Michal Simek <michal.simek at xilinx.com>
---

Changes in v4:
- Fix Kconfig typo - by sjg
- Use debug instead of puts in drivers - by sjg
- Use EBUSY instead of -1 - by sjg

Changes in v3:
 - Fix commit message
 - s/Axi/AXI
 - Use platdata instead of private data.
 - Remove \n from wdt reset to catch logs
 - Add debug to wdt_start

Changes in v2:
 - Rectified print message
 - Removed stop instruction from probe

Changes in v1:
 - Xilinx Axi wdt driver conversion to DM initial version

 drivers/watchdog/Kconfig         |   8 +++
 drivers/watchdog/xilinx_tb_wdt.c | 111 ++++++++++++++++++++++++++++++---------
 2 files changed, 93 insertions(+), 26 deletions(-)

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 148c6a0d687c..d545b3e00072 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -103,4 +103,12 @@ config WDT_CDNS
 	   Select this to enable Cadence watchdog timer, which can be found on some
 	   Xilinx Microzed Platform.
 
+config XILINX_TB_WATCHDOG
+	bool "Xilinx Axi watchdog timer support"
+	depends on WDT
+	imply WATCHDOG
+	help
+	   Select this to enable Xilinx Axi watchdog timer, which can be found on some
+	   Xilinx Microblaze Platforms.
+
 endmenu
diff --git a/drivers/watchdog/xilinx_tb_wdt.c b/drivers/watchdog/xilinx_tb_wdt.c
index 2274123e4919..929c8e60d37c 100644
--- a/drivers/watchdog/xilinx_tb_wdt.c
+++ b/drivers/watchdog/xilinx_tb_wdt.c
@@ -1,13 +1,17 @@
 // SPDX-License-Identifier: GPL-2.0+
 /*
- * Copyright (c) 2011-2013 Xilinx Inc.
+ * Xilinx AXI platforms watchdog timer driver.
+ *
+ * Author(s):	Michal Simek <michal.simek at xilinx.com>
+ *		Shreenidhi Shedi <yesshedi at gmail.com>
+ *
+ * Copyright (c) 2011-2018 Xilinx Inc.
  */
 
 #include <common.h>
-#include <asm/io.h>
-#include <asm/microblaze_intc.h>
-#include <asm/processor.h>
-#include <watchdog.h>
+#include <dm.h>
+#include <wdt.h>
+#include <linux/io.h>
 
 #define XWT_CSR0_WRS_MASK	0x00000008 /* Reset status Mask */
 #define XWT_CSR0_WDS_MASK	0x00000004 /* Timer state Mask */
@@ -20,49 +24,104 @@ struct watchdog_regs {
 	u32 tbr; /* 0x8 */
 };
 
-static struct watchdog_regs *watchdog_base =
-			(struct watchdog_regs *)CONFIG_WATCHDOG_BASEADDR;
+struct xlnx_wdt_platdata {
+	bool enable_once;
+	struct watchdog_regs *regs;
+};
 
-void hw_watchdog_reset(void)
+static int xlnx_wdt_reset(struct udevice *dev)
 {
 	u32 reg;
+	struct xlnx_wdt_platdata *platdata = dev_get_platdata(dev);
+
+	debug("%s ", __func__);
 
 	/* Read the current contents of TCSR0 */
-	reg = readl(&watchdog_base->twcsr0);
+	reg = readl(&platdata->regs->twcsr0);
 
 	/* Clear the watchdog WDS bit */
 	if (reg & (XWT_CSR0_EWDT1_MASK | XWT_CSRX_EWDT2_MASK))
-		writel(reg | XWT_CSR0_WDS_MASK, &watchdog_base->twcsr0);
+		writel(reg | XWT_CSR0_WDS_MASK, &platdata->regs->twcsr0);
+
+	return 0;
 }
 
-void hw_watchdog_disable(void)
+static int xlnx_wdt_stop(struct udevice *dev)
 {
 	u32 reg;
+	struct xlnx_wdt_platdata *platdata = dev_get_platdata(dev);
+
+	if (platdata->enable_once) {
+		debug("Can't stop Xilinx watchdog.\n");
+		return -EBUSY;
+	}
 
 	/* Read the current contents of TCSR0 */
-	reg = readl(&watchdog_base->twcsr0);
+	reg = readl(&platdata->regs->twcsr0);
+
+	writel(reg & ~XWT_CSR0_EWDT1_MASK, &platdata->regs->twcsr0);
+	writel(~XWT_CSRX_EWDT2_MASK, &platdata->regs->twcsr1);
 
-	writel(reg & ~XWT_CSR0_EWDT1_MASK, &watchdog_base->twcsr0);
-	writel(~XWT_CSRX_EWDT2_MASK, &watchdog_base->twcsr1);
+	debug("Watchdog disabled!\n");
 
-	puts("Watchdog disabled!\n");
+	return 0;
 }
 
-static void hw_watchdog_isr(void *arg)
+static int xlnx_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
 {
-	hw_watchdog_reset();
+	struct xlnx_wdt_platdata *platdata = dev_get_platdata(dev);
+
+	debug("%s:\n", __func__);
+
+	writel((XWT_CSR0_WRS_MASK | XWT_CSR0_WDS_MASK | XWT_CSR0_EWDT1_MASK),
+	       &platdata->regs->twcsr0);
+
+	writel(XWT_CSRX_EWDT2_MASK, &platdata->regs->twcsr1);
+
+	return 0;
 }
 
-void hw_watchdog_init(void)
+static int xlnx_wdt_probe(struct udevice *dev)
 {
-	int ret;
+	debug("%s: Probing wdt%u\n", __func__, dev->seq);
 
-	writel((XWT_CSR0_WRS_MASK | XWT_CSR0_WDS_MASK | XWT_CSR0_EWDT1_MASK),
-	       &watchdog_base->twcsr0);
-	writel(XWT_CSRX_EWDT2_MASK, &watchdog_base->twcsr1);
+	return 0;
+}
 
-	ret = install_interrupt_handler(CONFIG_WATCHDOG_IRQ,
-						hw_watchdog_isr, NULL);
-	if (ret)
-		puts("Watchdog IRQ registration failed.");
+static int xlnx_wdt_ofdata_to_platdata(struct udevice *dev)
+{
+	struct xlnx_wdt_platdata *platdata = dev_get_platdata(dev);
+
+	platdata->regs = (struct watchdog_regs *)dev_read_addr(dev);
+	if (IS_ERR(platdata->regs))
+		return PTR_ERR(platdata->regs);
+
+	platdata->enable_once = dev_read_u32_default(dev,
+						     "xlnx,wdt-enable-once", 0);
+
+	debug("%s: wdt-enable-once %d\n", __func__, platdata->enable_once);
+
+	return 0;
 }
+
+static const struct wdt_ops xlnx_wdt_ops = {
+	.start = xlnx_wdt_start,
+	.reset = xlnx_wdt_reset,
+	.stop = xlnx_wdt_stop,
+};
+
+static const struct udevice_id xlnx_wdt_ids[] = {
+	{ .compatible = "xlnx,xps-timebase-wdt-1.00.a", },
+	{ .compatible = "xlnx,xps-timebase-wdt-1.01.a", },
+	{},
+};
+
+U_BOOT_DRIVER(xlnx_wdt) = {
+	.name = "xlnx_wdt",
+	.id = UCLASS_WDT,
+	.of_match = xlnx_wdt_ids,
+	.probe = xlnx_wdt_probe,
+	.platdata_auto_alloc_size = sizeof(struct xlnx_wdt_platdata),
+	.ofdata_to_platdata = xlnx_wdt_ofdata_to_platdata,
+	.ops = &xlnx_wdt_ops,
+};
-- 
1.9.1