This driver supports the photonicat watchdog timers.
Signed-off-by: Coia Prant <coiapr...@gmail.com>
---
drivers/watchdog/Kconfig | 6 +
drivers/watchdog/Makefile | 1 +
drivers/watchdog/pcat_wdt.c | 218 ++++++++++++++++++++++++++++++++++++
3 files changed, 225 insertions(+)
create mode 100644 drivers/watchdog/pcat_wdt.c
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 0c3e9913..f0a52ecf 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -421,4 +421,10 @@ config WDT_FTWDT010
help
Faraday Technology ftwdt010 watchdog is an architecture independent
watchdog. It is usually used in SoC chip design.
+
+config WDT_PCAT
+ bool "photonicat board watchdog support"
+ depends on WDT && SERIAL && DM
+ help
+ Select this to enable watchdog timer on photonicat board.
endmenu
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 7b39adcf..829b5ed1 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -50,3 +50,4 @@ obj-$(CONFIG_WDT_STM32MP) += stm32mp_wdt.o
obj-$(CONFIG_WDT_SUNXI) += sunxi_wdt.o
obj-$(CONFIG_WDT_TANGIER) += tangier_wdt.o
obj-$(CONFIG_WDT_XILINX) += xilinx_wwdt.o
+obj-$(CONFIG_WDT_PCAT) += pcat_wdt.o
\ No newline at end of file
diff --git a/drivers/watchdog/pcat_wdt.c b/drivers/watchdog/pcat_wdt.c
new file mode 100644
index 00000000..cac07fb6
--- /dev/null
+++ b/drivers/watchdog/pcat_wdt.c
@@ -0,0 +1,218 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <dm.h>
+#include <dm/device_compat.h>
+#include <wdt.h>
+#include <asm/gpio.h>
+#include <linux/delay.h>
+#include <serial.h>
+#include <dm/device-internal.h>
+
+struct pcat_wdt_priv
+{
+ struct udevice *serial_dev;
+ struct dm_serial_ops *serial_ops;
+ uint16_t packet_count;
+};
+
+static uint16_t pcat_pmu_serial_compute_crc16(const uint8_t *data,
+
size_t len)
+{
+ uint16_t crc = 0xFFFF;
+ size_t i;
+ unsigned int j;
+
+ for (i = 0; i < len; i++)
+ {
+ crc ^= data[i];
+ for (j = 0; j < 8; j++)
+ {
+ if (crc & 1)
+ {
+ crc = (crc >> 1) ^ 0xA001;
+ }
+ else
+ {
+ crc >>= 1;
+ }
+ }
+ }
+
+ return crc;
+}
+
+static int pcat_wdt_reset(struct udevice *dev)
+{
+ struct pcat_wdt_priv *priv = dev_get_priv(dev);
+ uint8_t packet[13] = "\xA5\x01\x81\x00\x00\x03\x00\x01\x00"
+ "\x00\x00\x00\x5A";
+ uint16_t crc;
+ int err = 0;
+ unsigned int i;
+
+ packet[3] = priv->packet_count & 0xFF;
+ packet[4] = (priv->packet_count >> 8) & 0xFF;
+ priv->packet_count++;
+
+ crc = pcat_pmu_serial_compute_crc16(packet + 1, 9);
+ packet[10] = crc & 0xFF;
+ packet[11] = (crc >> 8) & 0xFF;
+
+ i = 0;
+ while (i < 13)
+ {
+ err = priv->serial_ops->putc(
+ priv->serial_dev, ((const char *)packet)[i]);
+ if (!err)
+ {
+ i++;
+ }
+ else if (err == -EAGAIN)
+ {
+ ;
+ }
+ else
+ {
+ pr_err("%s: unable to send watchdog setup "
+ "request: %d\n",
+ __func__, err);
+ break;
+ }
+ }
+ return err;
+}
+
+static int pcat_wdt_setup(struct pcat_wdt_priv *priv, u64 timeout)
+{
+ uint8_t packet[16] = "\xA5\x01\x81\x00\x00\x06\x00\x13\x00"
+ "\x3C\x3C\x00\x00\x00\x00\x5A";
+ uint16_t crc;
+ int err = 0;
+ unsigned int i;
+
+ if (timeout > 255)
+ {
+ pr_warn("%s: timeout cannot be more than 255s\n",
+ __func__);
+ timeout = 255;
+ }
+
+ packet[3] = priv->packet_count & 0xFF;
+ packet[4] = (priv->packet_count >> 8) & 0xFF;
+ priv->packet_count++;
+ packet[11] = timeout & 0xFF;
+
+ crc = pcat_pmu_serial_compute_crc16(packet + 1, 12);
+ packet[13] = crc & 0xFF;
+ packet[14] = (crc >> 8) & 0xFF;
+
+ i = 0;
+ while (i < 16)
+ {
+ err = priv->serial_ops->putc(
+ priv->serial_dev, ((const char *)packet)[i]);
+ if (!err)
+ {
+ i++;
+ }
+ else if (err == -EAGAIN)
+ {
+ ;
+ }
+ else
+ {
+ pr_err("%s: unable to send watchdog setup "
+ "request: %d\n",
+ __func__, err);
+ break;
+ }
+ }
+
+ return err;
+}
+
+static int pcat_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
+{
+ struct pcat_wdt_priv *priv = dev_get_priv(dev);
+
+ pcat_wdt_setup(priv, timeout);
+
+ return 0;
+}
+
+static int pcat_wdt_stop(struct udevice *dev)
+{
+ struct pcat_wdt_priv *priv = dev_get_priv(dev);
+
+ pcat_wdt_setup(priv, 0);
+
+ return 0;
+}
+
+static int dm_probe(struct udevice *dev)
+{
+ struct pcat_wdt_priv *priv = dev_get_priv(dev);
+ struct udevice *serial_dev = NULL;
+ struct dm_serial_ops *ops;
+ int ret;
+
+ ret = uclass_get_device_by_phandle(UCLASS_SERIAL, dev, "port",
+
&serial_dev);
+ if (ret)
+ {
+ pr_err("%s: unable to find serial port device: %d\n",
+ __func__, ret);
+ return ret;
+ }
+
+ ret = device_probe(serial_dev);
+ if (ret)
+ {
+ pr_err("%s: unable to probe serial port device: %d\n",
+ __func__, ret);
+ return ret;
+ }
+
+ ops = serial_get_ops(serial_dev);
+ if (!ops)
+ {
+ printf("Cannot get ops for PMU serial port!\n");
+ return -EINVAL;
+ }
+
+ if (ops->setconfig)
+ {
+ ops->setconfig(serial_dev, SERIAL_DEFAULT_CONFIG);
+ }
+ if (ops->setbrg)
+ {
+ ops->setbrg(serial_dev, 115200);
+ }
+
+ priv->serial_dev = serial_dev;
+ priv->serial_ops = ops;
+ priv->packet_count = 0;
+
+ pcat_wdt_stop(dev);
+
+ return 0;
+}
+
+static const struct wdt_ops pcat_wdt_ops = {
+ .start = pcat_wdt_start,
+ .reset = pcat_wdt_reset,
+ .stop = pcat_wdt_stop,
+};
+
+static const struct udevice_id pcat_wdt_ids[] = {
+ {.compatible = "linux,wdt-pcat"},
+ {}};
+
+U_BOOT_DRIVER(wdt_pcat) = {
+ .name = "wdt_pcat",
+ .id = UCLASS_WDT,
+ .of_match = pcat_wdt_ids,
+ .ops = &pcat_wdt_ops,
+ .probe = dm_probe,
+ .priv_auto = sizeof(struct pcat_wdt_priv),
+};
\ No newline at end of file
--
2.39.2
