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ARM: imx: add speed grading check for i.mx6 soc

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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 <b20788@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
This commit is contained in:
Anson Huang 2014-02-12 17:57:03 +08:00 committed by Shawn Guo
parent 6e6cdf6656
commit c962a09963
1 changed files with 23 additions and 3 deletions
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26
arch/arm/mach-imx/mach-imx6q.c
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@ -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);