cpufreq: qoriq: enhance bus frequency calculation

On some platforms, property device-type may be missed in soc node
in dts which caused the bus-frequency can not be obtained correctly.

This patch enhanced the bus-frequency calculation. When property
device-type is missed in dts, bus-frequency will be obtained by
looking up clock table to get platform clock and hence get its
frequency.

Signed-off-by: Tang Yuantian <andy.tang@nxp.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpufreq/qoriq-cpufreq.c b/drivers/cpufreq/qoriq-cpufreq.c
index bfec1bcd3835f3110f24e0fc9ee2ce16d8ceb5cb..e2ea433a5f9c3c57df47fd38531a315da9e4ec3e 100644 (file)
--- a/drivers/cpufreq/qoriq-cpufreq.c
+++ b/drivers/cpufreq/qoriq-cpufreq.c
@@ -52,17 +52,27 @@ static u32 get_bus_freq(void)
 {
        struct device_node *soc;
        u32 sysfreq;
+       struct clk *pltclk;
+       int ret;
 
+       /* get platform freq by searching bus-frequency property */
        soc = of_find_node_by_type(NULL, "soc");
-       if (!soc)
-               return 0;
-
-       if (of_property_read_u32(soc, "bus-frequency", &sysfreq))
-               sysfreq = 0;
+       if (soc) {
+               ret = of_property_read_u32(soc, "bus-frequency", &sysfreq);
+               of_node_put(soc);
+               if (!ret)
+                       return sysfreq;
+       }
 
-       of_node_put(soc);
+       /* get platform freq by its clock name */
+       pltclk = clk_get(NULL, "cg-pll0-div1");
+       if (IS_ERR(pltclk)) {
+               pr_err("%s: can't get bus frequency %ld\n",
+                      __func__, PTR_ERR(pltclk));
+               return PTR_ERR(pltclk);
+       }
 
-       return sysfreq;
+       return clk_get_rate(pltclk);
 }
 
 static struct clk *cpu_to_clk(int cpu)