On i.MX6UL, it has two type of part, the difference is the max ARM frequency that can run at(528MHz/700MHz). The part can be identified by part marking for speed grading fuse. This patch add speed grading check to disable the unsupported OPP dynamically. Signed-off-by: Bai Ping <ping.bai@xxxxxxx> --- arch/arm/mach-imx/mach-imx6ul.c | 78 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 77 insertions(+), 1 deletion(-) diff --git a/arch/arm/mach-imx/mach-imx6ul.c b/arch/arm/mach-imx/mach-imx6ul.c index 6cb8a22..bf86530 100644 --- a/arch/arm/mach-imx/mach-imx6ul.c +++ b/arch/arm/mach-imx/mach-imx6ul.c @@ -9,14 +9,17 @@ #include <linux/mfd/syscon.h> #include <linux/mfd/syscon/imx6q-iomuxc-gpr.h> #include <linux/micrel_phy.h> +#include <linux/of_address.h> #include <linux/of_platform.h> #include <linux/phy.h> +#include <linux/pm_opp.h> #include <linux/regmap.h> #include <asm/mach/arch.h> #include <asm/mach/map.h> #include "common.h" #include "cpuidle.h" +#include "hardware.h" static void __init imx6ul_enet_clk_init(void) { @@ -57,6 +60,76 @@ static inline void imx6ul_enet_init(void) imx6ul_enet_phy_init(); } +#define OCOTP_CFG3 0x440 +#define OCOTP_CFG3_SPEED_SHIFT 16 +#define OCOTP_CFG3_SPEED_696MHZ 0x2 + +static void __init imx6ul_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,imx6ul-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'00: Reserved; + * 2b'01: 528000000Hz; + * 2b'10: 700000000Hz; + * 2b'11: Reserved; + * 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_696MHZ) { + if (dev_pm_opp_disable(cpu_dev, 696000000)) + pr_warn("Failed to disable 696MHz OPP\n"); + } + iounmap(base); + +put_node: + of_node_put(np); +} + +static void __init imx6ul_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; + } + + imx6ul_opp_check_speed_grading(cpu_dev); + +put_node: + of_node_put(np); +} + static void __init imx6ul_init_machine(void) { struct device *parent; @@ -83,8 +156,11 @@ static void __init imx6ul_init_late(void) { imx6sx_cpuidle_init(); - if (IS_ENABLED(CONFIG_ARM_IMX6Q_CPUFREQ)) + if (IS_ENABLED(CONFIG_ARM_IMX6Q_CPUFREQ)) { + if (cpu_is_imx6ul()) + imx6ul_opp_init(); platform_device_register_simple("imx6q-cpufreq", -1, NULL, 0); + } } static const char * const imx6ul_dt_compat[] __initconst = { -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html