speed grading check, opp table will not be created in platform code,
so cpufreq driver prints the following error message:

cpu cpu0: dev_pm_opp_get_opp_count: OPP table not found (-19)

However, this is not really an error in this case because the
imx6q-cpufreq driver first calls dev_pm_opp_get_opp_count()
and if it fails, it means that platform code does not provide
OPP and then dev_pm_opp_of_add_table() will be called.

In order to avoid such confusing error message, move the speed grading
check from platform code to the imx6q-cpufreq driver.

This way the imx6q-cpufreq no longer has to check whether OPP table
is supplied by platform code.

Tested on a i.MX6Q and i.MX6UL based boards.

Signed-off-by: Fabio Estevam <redacted>
---
Previous discussion on this topic:
https://patchwork.kernel.org/patch/9295059/

Changes since v1:
- Remove unneeded has_speed_grading() function.

 arch/arm/mach-imx/mach-imx6q.c  | 88 +----------------------------------------
 drivers/cpufreq/imx6q-cpufreq.c | 85 +++++++++++++++++++++++++++++----------
 2 files changed, 67 insertions(+), 106 deletions(-)

diff --git a/arch/arm/mach-imx/mach-imx6q.c b/arch/arm/mach-imx/mach-imx6q.c
index 45801b2..b5f89fd 100644
--- a/arch/arm/mach-imx/mach-imx6q.c
+++ b/arch/arm/mach-imx/mach-imx6q.c

@@ -286,88 +286,6 @@ static void __init imx6q_init_machine(void)
        imx6q_axi_init();
 }

-#define OCOTP_CFG3                     0x440
-#define OCOTP_CFG3_SPEED_SHIFT         16
-#define OCOTP_CFG3_SPEED_1P2GHZ                0x3
-#define OCOTP_CFG3_SPEED_996MHZ                0x2
-#define OCOTP_CFG3_SPEED_852MHZ                0x1
-
-static void __init imx6q_opp_check_speed_grading(struct device *cpu_dev)
-{
-       struct device_node *np;
-       void __iomem *base;
-       u32 val;
-
-       np = of_find_compatible_node(NULL, NULL, "fsl,imx6q-ocotp");
-       if (!np) {
-               pr_warn("failed to find ocotp node\n");
-               return;
-       }
-
-       base = of_iomap(np, 0);
-       if (!base) {
-               pr_warn("failed to map ocotp\n");
-               goto put_node;
-       }
-
-       /*
-        * SPEED_GRADING[1:0] defines the max speed of ARM:
-        * 2b'11: 1200000000Hz;
-        * 2b'10: 996000000Hz;
-        * 2b'01: 852000000Hz; -- i.MX6Q Only, exclusive with 996MHz.
-        * 2b'00: 792000000Hz;
-        * We need to set the max speed of ARM according to fuse map.
-        */
-       val = readl_relaxed(base + OCOTP_CFG3);
-       val >>= OCOTP_CFG3_SPEED_SHIFT;
-       val &= 0x3;
-
-       if ((val != OCOTP_CFG3_SPEED_1P2GHZ) && cpu_is_imx6q())
-               if (dev_pm_opp_disable(cpu_dev, 1200000000))
-                       pr_warn("failed to disable 1.2 GHz OPP\n");
-       if (val < OCOTP_CFG3_SPEED_996MHZ)
-               if (dev_pm_opp_disable(cpu_dev, 996000000))
-                       pr_warn("failed to disable 996 MHz OPP\n");
-       if (cpu_is_imx6q()) {
-               if (val != OCOTP_CFG3_SPEED_852MHZ)
-                       if (dev_pm_opp_disable(cpu_dev, 852000000))
-                               pr_warn("failed to disable 852 MHz OPP\n");
-       }
-       iounmap(base);
-put_node:
-       of_node_put(np);
-}
-
-static void __init imx6q_opp_init(void)
-{
-       struct device_node *np;
-       struct device *cpu_dev = get_cpu_device(0);
-
-       if (!cpu_dev) {
-               pr_warn("failed to get cpu0 device\n");
-               return;
-       }
-       np = of_node_get(cpu_dev->of_node);
-       if (!np) {
-               pr_warn("failed to find cpu0 node\n");
-               return;
-       }
-
-       if (dev_pm_opp_of_add_table(cpu_dev)) {
-               pr_warn("failed to init OPP table\n");
-               goto put_node;
-       }
-
-       imx6q_opp_check_speed_grading(cpu_dev);
-
-put_node:
-       of_node_put(np);
-}
-
-static struct platform_device imx6q_cpufreq_pdev = {
-       .name = "imx6q-cpufreq",
-};
-
 static void __init imx6q_init_late(void)
 {
        /*

@@ -377,10 +295,8 @@ static void __init imx6q_init_late(void)
        if (imx_get_soc_revision() > IMX_CHIP_REVISION_1_1)
                imx6q_cpuidle_init();

-       if (IS_ENABLED(CONFIG_ARM_IMX6Q_CPUFREQ)) {
-               imx6q_opp_init();
-               platform_device_register(&imx6q_cpufreq_pdev);
-       }
+       if (IS_ENABLED(CONFIG_ARM_IMX6Q_CPUFREQ))
+               platform_device_register_simple("imx6q-cpufreq", -1, NULL, 0);
 }

 static void __init imx6q_map_io(void)

diff --git a/drivers/cpufreq/imx6q-cpufreq.c b/drivers/cpufreq/imx6q-cpufreq.c
index 14466a9..45d90e6 100644
--- a/drivers/cpufreq/imx6q-cpufreq.c
+++ b/drivers/cpufreq/imx6q-cpufreq.c

@@ -12,6 +12,7 @@
 #include <linux/err.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_address.h>
 #include <linux/pm_opp.h>
 #include <linux/platform_device.h>
 #include <linux/regulator/consumer.h>

@@ -191,6 +192,57 @@ static struct cpufreq_driver imx6q_cpufreq_driver = {
        .suspend = cpufreq_generic_suspend,
 };

+#define OCOTP_CFG3                     0x440
+#define OCOTP_CFG3_SPEED_SHIFT         16
+#define OCOTP_CFG3_SPEED_1P2GHZ                0x3
+#define OCOTP_CFG3_SPEED_996MHZ                0x2
+#define OCOTP_CFG3_SPEED_852MHZ                0x1
+
+static void __init imx6q_opp_check_speed_grading(struct device *dev)
+{
+       struct device_node *np;
+       void __iomem *base;
+       u32 val;
+
+       np = of_find_compatible_node(NULL, NULL, "fsl,imx6q-ocotp");
+       if (!np)
+               return;
+
+       base = of_iomap(np, 0);
+       if (!base) {
+               dev_err(dev, "failed to map ocotp\n");
+               goto put_node;
+       }
+
+       /*
+        * SPEED_GRADING[1:0] defines the max speed of ARM:
+        * 2b'11: 1200000000Hz;
+        * 2b'10: 996000000Hz;
+        * 2b'01: 852000000Hz; -- i.MX6Q Only, exclusive with 996MHz.
+        * 2b'00: 792000000Hz;
+        * We need to set the max speed of ARM according to fuse map.
+        */
+       val = readl_relaxed(base + OCOTP_CFG3);
+       val >>= OCOTP_CFG3_SPEED_SHIFT;
+       val &= 0x3;
+
+       if ((val != OCOTP_CFG3_SPEED_1P2GHZ) &&
+            of_machine_is_compatible("fsl,imx6q"))
+               if (dev_pm_opp_disable(dev, 1200000000))
+                       dev_warn(dev, "failed to disable 1.2GHz OPP\n");
+       if (val < OCOTP_CFG3_SPEED_996MHZ)
+               if (dev_pm_opp_disable(dev, 996000000))
+                       dev_warn(dev, "failed to disable 996MHz OPP\n");
+       if (of_machine_is_compatible("fsl,imx6q")) {
+               if (val != OCOTP_CFG3_SPEED_852MHZ)
+                       if (dev_pm_opp_disable(dev, 852000000))
+                               dev_warn(dev, "failed to disable 852MHz OPP\n");
+       }
+       iounmap(base);
+put_node:
+       of_node_put(np);
+}
+
 static int imx6q_cpufreq_probe(struct platform_device *pdev)
 {
        struct device_node *np;

@@ -252,28 +304,21 @@ static int imx6q_cpufreq_probe(struct platform_device *pdev)
                goto put_reg;
        }

-       /*
-        * We expect an OPP table supplied by platform.
-        * Just, incase the platform did not supply the OPP
-        * table, it will try to get it.
-        */
-       num = dev_pm_opp_get_opp_count(cpu_dev);
-       if (num < 0) {
-               ret = dev_pm_opp_of_add_table(cpu_dev);
-               if (ret < 0) {
-                       dev_err(cpu_dev, "failed to init OPP table: %d\n", ret);
-                       goto put_reg;
-               }
+       ret = dev_pm_opp_of_add_table(cpu_dev);
+       if (ret < 0) {
+               dev_err(cpu_dev, "failed to init OPP table: %d\n", ret);
+               goto put_reg;
+       }

-               /* Because we have added the OPPs here, we must free them */
-               free_opp = true;
+       imx6q_opp_check_speed_grading(cpu_dev);

-               num = dev_pm_opp_get_opp_count(cpu_dev);
-               if (num < 0) {
-                       ret = num;
-                       dev_err(cpu_dev, "no OPP table is found: %d\n", ret);
-                       goto out_free_opp;
-               }
+       /* Because we have added the OPPs here, we must free them */
+       free_opp = true;
+       num = dev_pm_opp_get_opp_count(cpu_dev);
+       if (num < 0) {
+               ret = num;
+               dev_err(cpu_dev, "no OPP table is found: %d\n", ret);
+               goto out_free_opp;
        }

        ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
--

2.7.4


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