[PATCH V2 2/2] ARM: imx: add speed grading check for i.mx6 soc
From: Anson Huang <hidden>
Date: 2014-02-12 09:57:03
Also in:
linux-devicetree
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
The fuse map of speed_grading[1:0] defines the max speed of ARM, see below the definition: 2b'11: 1200000000Hz; 2b'10: 996000000Hz; 2b'01: 852000000Hz; -- i.MX6Q Only, exclusive with 996MHz. 2b'00: 792000000Hz; Need to remove all illegal setpoints according to fuse map. Signed-off-by: Anson Huang <redacted> --- arch/arm/mach-imx/mach-imx6q.c | 26 +++++++++++++++++++++++--- 1 file changed, 23 insertions(+), 3 deletions(-)
diff --git a/arch/arm/mach-imx/mach-imx6q.c b/arch/arm/mach-imx/mach-imx6q.c
index d131499..1e12685 100644
--- a/arch/arm/mach-imx/mach-imx6q.c
+++ b/arch/arm/mach-imx/mach-imx6q.c@@ -253,8 +253,10 @@ static void __init imx6q_init_machine(void) #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_1p2ghz(struct device *cpu_dev) +static void __init imx6q_opp_check_speed_grading(struct device *cpu_dev) { struct device_node *np; void __iomem *base;
@@ -272,11 +274,29 @@ static void __init imx6q_opp_check_1p2ghz(struct device *cpu_dev) 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; - if ((val & 0x3) != OCOTP_CFG3_SPEED_1P2GHZ) + val &= 0x3; + + if (val != OCOTP_CFG3_SPEED_1P2GHZ) 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"); + } put_node: of_node_put(np);
@@ -302,7 +322,7 @@ static void __init imx6q_opp_init(void) goto put_node; } - imx6q_opp_check_1p2ghz(cpu_dev); + imx6q_opp_check_speed_grading(cpu_dev); put_node: of_node_put(np);
--
1.7.9.5