On 07/23/2018 01:37 AM, Srinath Mannam wrote:
Use clock-frequency property given in _DSD object
of ACPI device to calculate Watchdog rate as binding
clock devices are not available as device tree.

Note: There is no formal review process for _DSD
properties

Signed-off-by: Srinath Mannam <srinath.man...@broadcom.com>
Signed-off-by: Guenter Roeck <li...@roeck-us.net>

I just noticed this. This is completely inappropriate. It is
the equivalent of forging a signature on a check.

_Never_ add a Signed-off-by: statement for anyone but yourself.

Guenter

Reviewed-by: Guenter Roeck <li...@roeck-us.net>
Reviewed-by: Ray Jui <ray....@broadcom.com>
Reviewed-by: Scott Branden <scott.bran...@broadcom.com>
---
  drivers/watchdog/sp805_wdt.c | 35 +++++++++++++++++++++++++----------
  1 file changed, 25 insertions(+), 10 deletions(-)

diff --git a/drivers/watchdog/sp805_wdt.c b/drivers/watchdog/sp805_wdt.c
index 9849db0..a896b1c 100644
--- a/drivers/watchdog/sp805_wdt.c
+++ b/drivers/watchdog/sp805_wdt.c
@@ -11,6 +11,7 @@
   * warranty of any kind, whether express or implied.
   */
+#include <linux/acpi.h>
  #include <linux/device.h>
  #include <linux/resource.h>
  #include <linux/amba/bus.h>
@@ -22,6 +23,7 @@
  #include <linux/math64.h>
  #include <linux/module.h>
  #include <linux/moduleparam.h>
+#include <linux/of.h>
  #include <linux/pm.h>
  #include <linux/slab.h>
  #include <linux/spinlock.h>
@@ -65,6 +67,7 @@ struct sp805_wdt {
        spinlock_t                      lock;
        void __iomem                    *base;
        struct clk                      *clk;
+       u64                             rate;
        struct amba_device              *adev;
        unsigned int                    load_val;
  };
@@ -80,7 +83,7 @@ static int wdt_setload(struct watchdog_device *wdd, unsigned 
int timeout)
        struct sp805_wdt *wdt = watchdog_get_drvdata(wdd);
        u64 load, rate;
- rate = clk_get_rate(wdt->clk);
+       rate = wdt->rate;
/*
         * sp805 runs counter with given value twice, after the end of first
@@ -106,9 +109,7 @@ static int wdt_setload(struct watchdog_device *wdd, 
unsigned int timeout)
  static unsigned int wdt_timeleft(struct watchdog_device *wdd)
  {
        struct sp805_wdt *wdt = watchdog_get_drvdata(wdd);
-       u64 load, rate;
-
-       rate = clk_get_rate(wdt->clk);
+       u64 load;
spin_lock(&wdt->lock);
        load = readl_relaxed(wdt->base + WDTVALUE);
@@ -118,7 +119,7 @@ static unsigned int wdt_timeleft(struct watchdog_device 
*wdd)
                load += wdt->load_val + 1;
        spin_unlock(&wdt->lock);
- return div_u64(load, rate);
+       return div_u64(load, wdt->rate);
  }
static int
@@ -228,11 +229,25 @@ sp805_wdt_probe(struct amba_device *adev, const struct 
amba_id *id)
        if (IS_ERR(wdt->base))
                return PTR_ERR(wdt->base);
- wdt->clk = devm_clk_get(&adev->dev, NULL);
-       if (IS_ERR(wdt->clk)) {
-               dev_warn(&adev->dev, "Clock not found\n");
-               ret = PTR_ERR(wdt->clk);
-               goto err;
+       if (adev->dev.of_node) {
+               wdt->clk = devm_clk_get(&adev->dev, NULL);
+               if (IS_ERR(wdt->clk)) {
+                       dev_err(&adev->dev, "Clock not found\n");
+                       return PTR_ERR(wdt->clk);
+               }
+               wdt->rate = clk_get_rate(wdt->clk);
+       } else if (has_acpi_companion(&adev->dev)) {
+               /*
+                * When Driver probe with ACPI device, clock devices
+                * are not available, so watchdog rate get from
+                * clock-frequency property given in _DSD object.
+                */
+               device_property_read_u64(&adev->dev, "clock-frequency",
+                                        &wdt->rate);
+               if (!wdt->rate) {
+                       dev_err(&adev->dev, "no clock-frequency property\n");
+                       return -ENODEV;
+               }
        }
wdt->adev = adev;


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