[PATCH v2] cpufreq: imx6q: Move speed grading check to cpufreq driver
Otavio Salvador
otavio.salvador at ossystems.com.br
Sat Sep 30 07:36:06 PDT 2017
On Sat, Sep 30, 2017 at 9:13 AM, Fabio Estevam <festevam at gmail.com> wrote:
> From: Fabio Estevam <fabio.estevam at nxp.com>
>
> On some i.MX6 SoCs (like i.MX6UL, i.MX6SX and i.MX6UL) that do not have
two UL ?
> 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 <fabio.estevam at nxp.com>
> ---
> 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
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
--
Otavio Salvador O.S. Systems
http://www.ossystems.com.br http://code.ossystems.com.br
Mobile: +55 (53) 9981-7854 Mobile: +1 (347) 903-9750
More information about the linux-arm-kernel
mailing list