Re: [PATCH v2 2/3] watchdog: add designware driver

2016-10-17 Thread Steffen Trumtrar 
On Fri, Oct 14, 2016 at 11:27:14AM +0200, Steffen Trumtrar wrote:
> Port the linux v4.8-rc1 Synopsys DesignWare watchdog driver to barebox.
> 
> Signed-off-by: Steffen Trumtrar 
> ---
> Changes since v1:
>   - change usages of pr_warn in favor of dev_warn
> 
>  drivers/watchdog/Kconfig  |   6 ++
>  drivers/watchdog/Makefile |   1 +
>  drivers/watchdog/dw_wdt.c | 193 
> ++
>  3 files changed, 200 insertions(+)
>  create mode 100644 drivers/watchdog/dw_wdt.c
> 

(...)

> +struct dw_wdt {
> + void __iomem*regs;
> + struct clk  *clk;
> + struct restart_handler  restart;
> + struct watchdog wdd;
> + struct reset_control*rst;
> +};
> +

(...)

> +static int dw_wdt_stop(struct watchdog *wdd)
> +{
> + struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
> +
> + if (IS_ERR(dw_wdt->rst)) {
> + dev_warn(dw_wdt->dev, "No reset line. Will not stop.\n");
 ^^^

Meh, I sent the wrong version :-(
Let's try again.

Regards,
Steffen

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[PATCH v2 2/3] watchdog: add designware driver

2016-10-14 Thread Steffen Trumtrar 
Port the linux v4.8-rc1 Synopsys DesignWare watchdog driver to barebox.

Signed-off-by: Steffen Trumtrar 
---
Changes since v1:
  - change usages of pr_warn in favor of dev_warn

 drivers/watchdog/Kconfig  |   6 ++
 drivers/watchdog/Makefile |   1 +
 drivers/watchdog/dw_wdt.c | 193 ++
 3 files changed, 200 insertions(+)
 create mode 100644 drivers/watchdog/dw_wdt.c

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 60a56bf4b030..63fb1a8c5701 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -16,6 +16,12 @@ config WATCHDOG_DAVINCI
help
  Add support for watchdog on the TI Davinci SoC.
 
+config WATCHDOG_DW
+   bool "Synopsys DesignWare watchdog"
+   select RESET_CONTROLLER
+   help
+ Add support for the Synopsys DesignWare watchdog timer.
+
 config WATCHDOG_MXS28
bool "i.MX28"
depends on ARCH_IMX28
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index e3afe1c27efb..5fca4c368c40 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -2,5 +2,6 @@ obj-$(CONFIG_WATCHDOG) += wd_core.o
 obj-$(CONFIG_WATCHDOG_DAVINCI) += davinci_wdt.o
 obj-$(CONFIG_WATCHDOG_OMAP) += omap_wdt.o
 obj-$(CONFIG_WATCHDOG_MXS28) += im28wd.o
+obj-$(CONFIG_WATCHDOG_DW) += dw_wdt.o
 obj-$(CONFIG_WATCHDOG_JZ4740) += jz4740.o
 obj-$(CONFIG_WATCHDOG_IMX_RESET_SOURCE) += imxwd.o
diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c
new file mode 100644
index ..6de2b84356dc
--- /dev/null
+++ b/drivers/watchdog/dw_wdt.c
@@ -0,0 +1,193 @@
+/*
+ * Copyright 2010-2011 Picochip Ltd., Jamie Iles
+ * http://www.picochip.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * This file implements a driver for the Synopsys DesignWare watchdog device
+ * in the many subsystems. The watchdog has 16 different timeout periods
+ * and these are a function of the input clock frequency.
+ *
+ * The DesignWare watchdog cannot be stopped once it has been started so we
+ * do not implement a stop function. The watchdog core will continue to send
+ * heartbeat requests after the watchdog device has been closed.
+ */
+
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+
+#define WDOG_CONTROL_REG_OFFSET0x00
+#define WDOG_CONTROL_REG_WDT_EN_MASK   0x01
+#define WDOG_TIMEOUT_RANGE_REG_OFFSET  0x04
+#define WDOG_TIMEOUT_RANGE_TOPINIT_SHIFT4
+#define WDOG_CURRENT_COUNT_REG_OFFSET  0x08
+#define WDOG_COUNTER_RESTART_REG_OFFSET 0x0c
+#define WDOG_COUNTER_RESTART_KICK_VALUE0x76
+
+/* The maximum TOP (timeout period) value that can be set in the watchdog. */
+#define DW_WDT_MAX_TOP 15
+
+#define DW_WDT_DEFAULT_SECONDS 30
+
+struct dw_wdt {
+   void __iomem*regs;
+   struct clk  *clk;
+   struct restart_handler  restart;
+   struct watchdog wdd;
+   struct reset_control*rst;
+};
+
+#define to_dw_wdt(wdd) container_of(wdd, struct dw_wdt, wdd)
+
+static inline int dw_wdt_top_in_seconds(struct dw_wdt *dw_wdt, unsigned top)
+{
+   /*
+* There are 16 possible timeout values in 0..15 where the number of
+* cycles is 2 ^ (16 + i) and the watchdog counts down.
+*/
+   return (1U << (16 + top)) / clk_get_rate(dw_wdt->clk);
+}
+
+static int dw_wdt_start(struct watchdog *wdd)
+{
+   struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
+
+   writel(WDOG_CONTROL_REG_WDT_EN_MASK,
+  dw_wdt->regs + WDOG_CONTROL_REG_OFFSET);
+
+   return 0;
+}
+
+static int dw_wdt_stop(struct watchdog *wdd)
+{
+   struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
+
+   if (IS_ERR(dw_wdt->rst)) {
+   dev_warn(dw_wdt->dev, "No reset line. Will not stop.\n");
+   return PTR_ERR(dw_wdt->rst);
+   }
+
+   reset_control_assert(dw_wdt->rst);
+   reset_control_deassert(dw_wdt->rst);
+
+   return 0;
+}
+
+static int dw_wdt_set_timeout(struct watchdog *wdd, unsigned int top_s)
+{
+   struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
+   int i, top_val = DW_WDT_MAX_TOP;
+
+   if (top_s == 0)
+   return dw_wdt_stop(wdd);
+
+   /*
+* Iterate over the timeout values until we find the closest match. We
+* always look for >=.
+*/
+   for (i = 0; i <= DW_WDT_MAX_TOP; ++i) {
+   if (dw_wdt_top_in_seconds(dw_wdt, i) >= top_s) {
+   top_val = i;
+   break;
+   }
+   }
+
+   /*
+* Set the new value in the watchdog.  Some versions of dw_wdt
+* have have TOPINIT in the TIMEOUT_RANGE register (as per
+*