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linux/arch/arm/mach-imx/mach-imx6q.c
Shawn Guo 35e2916f70 ARM: imx6: initialize CCM_CLPCR_LPM into RUN mode earlier 
Commit 4631960d26da ("ARM: imx6: set initial power mode in pm function")
moves imx6_set_lpm() from clock init function into
imx6_pm_common_init().  This causes a hang when cpuidle support is
enabled.  The reason for that is ARM core clock is shut down
unexpectedly by WAIT mode.  It happens with the following call stack:

    cpuidle_register_governor()
        cpuidle_switch_governor()
            cpuidle_uninstall_idle_handler()
                synchronize_sched()
                    wait_rcu_gp()
                        wait_for_completion()

When wait_for_completion() is called as above, all cores are idle/WFI.
Hence, the reset value of CCM_CLPCR_LPM - WAIT mode, will trigger a
hardware shutdown of the ARM core clock.

To fix the regression, we need to ensure that CCM_CLPCR_LPM is
initialized into RUN mode earlier than cpuidle governor registration,
which is a postcore_initcall.  This patch creates function
imx6_pm_ccm_init() to map CCM block and initialize CCM_CLPCR_LPM into
RUN mode, and have the function called from machine .init_irq hook,
which should be early enough.

Reported-by: Kevin Hilman <khilman@kernel.org>
Fixes: 8fb76a07e2 ("ARM: imx6: set initial power mode in pm function")
Tested-by: Kevin Hilman <khilman@linaro.org>
Tested-by: Tyler Baker <tyler.baker@linaro.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
2015-06-03 14:49:18 +08:00

413 lines
9.9 KiB
C
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/*
* Copyright 2011-2013 Freescale Semiconductor, Inc.
* Copyright 2011 Linaro Ltd.
*
* The code contained herein is licensed under the GNU General Public
* License. You may obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*/
#include <linux/clk.h>
#include <linux/clkdev.h>
#include <linux/cpu.h>
#include <linux/delay.h>
#include <linux/export.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/irqchip.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/pm_opp.h>
#include <linux/pci.h>
#include <linux/phy.h>
#include <linux/reboot.h>
#include <linux/regmap.h>
#include <linux/micrel_phy.h>
#include <linux/mfd/syscon.h>
#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
#include <asm/mach/arch.h>
#include <asm/mach/map.h>
#include <asm/system_misc.h>
#include "common.h"
#include "cpuidle.h"
#include "hardware.h"
/* For imx6q sabrelite board: set KSZ9021RN RGMII pad skew */
static int ksz9021rn_phy_fixup(struct phy_device *phydev)
{
if (IS_BUILTIN(CONFIG_PHYLIB)) {
/* min rx data delay */
phy_write(phydev, MICREL_KSZ9021_EXTREG_CTRL,
0x8000 | MICREL_KSZ9021_RGMII_RX_DATA_PAD_SCEW);
phy_write(phydev, MICREL_KSZ9021_EXTREG_DATA_WRITE, 0x0000);
/* max rx/tx clock delay, min rx/tx control delay */
phy_write(phydev, MICREL_KSZ9021_EXTREG_CTRL,
0x8000 | MICREL_KSZ9021_RGMII_CLK_CTRL_PAD_SCEW);
phy_write(phydev, MICREL_KSZ9021_EXTREG_DATA_WRITE, 0xf0f0);
phy_write(phydev, MICREL_KSZ9021_EXTREG_CTRL,
MICREL_KSZ9021_RGMII_CLK_CTRL_PAD_SCEW);
}
return 0;
}
static void mmd_write_reg(struct phy_device *dev, int device, int reg, int val)
{
phy_write(dev, 0x0d, device);
phy_write(dev, 0x0e, reg);
phy_write(dev, 0x0d, (1 << 14) | device);
phy_write(dev, 0x0e, val);
}
static int ksz9031rn_phy_fixup(struct phy_device *dev)
{
/*
* min rx data delay, max rx/tx clock delay,
* min rx/tx control delay
*/
mmd_write_reg(dev, 2, 4, 0);
mmd_write_reg(dev, 2, 5, 0);
mmd_write_reg(dev, 2, 8, 0x003ff);
return 0;
}
/*
* fixup for PLX PEX8909 bridge to configure GPIO1-7 as output High
* as they are used for slots1-7 PERST#
*/
static void ventana_pciesw_early_fixup(struct pci_dev *dev)
{
u32 dw;
if (!of_machine_is_compatible("gw,ventana"))
return;
if (dev->devfn != 0)
return;
pci_read_config_dword(dev, 0x62c, &dw);
dw |= 0xaaa8; // GPIO1-7 outputs
pci_write_config_dword(dev, 0x62c, dw);
pci_read_config_dword(dev, 0x644, &dw);
dw |= 0xfe; // GPIO1-7 output high
pci_write_config_dword(dev, 0x644, dw);
msleep(100);
}
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_PLX, 0x8609, ventana_pciesw_early_fixup);
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_PLX, 0x8606, ventana_pciesw_early_fixup);
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_PLX, 0x8604, ventana_pciesw_early_fixup);
static int ar8031_phy_fixup(struct phy_device *dev)
{
u16 val;
/* To enable AR8031 output a 125MHz clk from CLK_25M */
phy_write(dev, 0xd, 0x7);
phy_write(dev, 0xe, 0x8016);
phy_write(dev, 0xd, 0x4007);
val = phy_read(dev, 0xe);
val &= 0xffe3;
val |= 0x18;
phy_write(dev, 0xe, val);
/* introduce tx clock delay */
phy_write(dev, 0x1d, 0x5);
val = phy_read(dev, 0x1e);
val |= 0x0100;
phy_write(dev, 0x1e, val);
return 0;
}
#define PHY_ID_AR8031 0x004dd074
static int ar8035_phy_fixup(struct phy_device *dev)
{
u16 val;
/* Ar803x phy SmartEEE feature cause link status generates glitch,
* which cause ethernet link down/up issue, so disable SmartEEE
*/
phy_write(dev, 0xd, 0x3);
phy_write(dev, 0xe, 0x805d);
phy_write(dev, 0xd, 0x4003);
val = phy_read(dev, 0xe);
phy_write(dev, 0xe, val & ~(1 << 8));
/*
* Enable 125MHz clock from CLK_25M on the AR8031. This
* is fed in to the IMX6 on the ENET_REF_CLK (V22) pad.
* Also, introduce a tx clock delay.
*
* This is the same as is the AR8031 fixup.
*/
ar8031_phy_fixup(dev);
/*check phy power*/
val = phy_read(dev, 0x0);
if (val & BMCR_PDOWN)
phy_write(dev, 0x0, val & ~BMCR_PDOWN);
return 0;
}
#define PHY_ID_AR8035 0x004dd072
static void __init imx6q_enet_phy_init(void)
{
if (IS_BUILTIN(CONFIG_PHYLIB)) {
phy_register_fixup_for_uid(PHY_ID_KSZ9021, MICREL_PHY_ID_MASK,
ksz9021rn_phy_fixup);
phy_register_fixup_for_uid(PHY_ID_KSZ9031, MICREL_PHY_ID_MASK,
ksz9031rn_phy_fixup);
phy_register_fixup_for_uid(PHY_ID_AR8031, 0xffffffff,
ar8031_phy_fixup);
phy_register_fixup_for_uid(PHY_ID_AR8035, 0xffffffef,
ar8035_phy_fixup);
}
}
static void __init imx6q_1588_init(void)
{
struct device_node *np;
struct clk *ptp_clk;
struct clk *enet_ref;
struct regmap *gpr;
u32 clksel;
np = of_find_compatible_node(NULL, NULL, "fsl,imx6q-fec");
if (!np) {
pr_warn("%s: failed to find fec node\n", __func__);
return;
}
ptp_clk = of_clk_get(np, 2);
if (IS_ERR(ptp_clk)) {
pr_warn("%s: failed to get ptp clock\n", __func__);
goto put_node;
}
enet_ref = clk_get_sys(NULL, "enet_ref");
if (IS_ERR(enet_ref)) {
pr_warn("%s: failed to get enet clock\n", __func__);
goto put_ptp_clk;
}
/*
* If enet_ref from ANATOP/CCM is the PTP clock source, we need to
* set bit IOMUXC_GPR1[21]. Or the PTP clock must be from pad
* (external OSC), and we need to clear the bit.
*/
clksel = clk_is_match(ptp_clk, enet_ref) ?
IMX6Q_GPR1_ENET_CLK_SEL_ANATOP :
IMX6Q_GPR1_ENET_CLK_SEL_PAD;
gpr = syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr");
if (!IS_ERR(gpr))
regmap_update_bits(gpr, IOMUXC_GPR1,
IMX6Q_GPR1_ENET_CLK_SEL_MASK,
clksel);
else
pr_err("failed to find fsl,imx6q-iomux-gpr regmap\n");
clk_put(enet_ref);
put_ptp_clk:
clk_put(ptp_clk);
put_node:
of_node_put(np);
}
static void __init imx6q_axi_init(void)
{
struct regmap *gpr;
unsigned int mask;
gpr = syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr");
if (!IS_ERR(gpr)) {
/*
* Enable the cacheable attribute of VPU and IPU
* AXI transactions.
*/
mask = IMX6Q_GPR4_VPU_WR_CACHE_SEL |
IMX6Q_GPR4_VPU_RD_CACHE_SEL |
IMX6Q_GPR4_VPU_P_WR_CACHE_VAL |
IMX6Q_GPR4_VPU_P_RD_CACHE_VAL_MASK |
IMX6Q_GPR4_IPU_WR_CACHE_CTL |
IMX6Q_GPR4_IPU_RD_CACHE_CTL;
regmap_update_bits(gpr, IOMUXC_GPR4, mask, mask);
/* Increase IPU read QoS priority */
regmap_update_bits(gpr, IOMUXC_GPR6,
IMX6Q_GPR6_IPU1_ID00_RD_QOS_MASK |
IMX6Q_GPR6_IPU1_ID01_RD_QOS_MASK,
(0xf << 16) | (0x7 << 20));
regmap_update_bits(gpr, IOMUXC_GPR7,
IMX6Q_GPR7_IPU2_ID00_RD_QOS_MASK |
IMX6Q_GPR7_IPU2_ID01_RD_QOS_MASK,
(0xf << 16) | (0x7 << 20));
} else {
pr_warn("failed to find fsl,imx6q-iomuxc-gpr regmap\n");
}
}
static void __init imx6q_init_machine(void)
{
struct device *parent;
imx_print_silicon_rev(cpu_is_imx6dl() ? "i.MX6DL" : "i.MX6Q",
imx_get_soc_revision());
parent = imx_soc_device_init();
if (parent == NULL)
pr_warn("failed to initialize soc device\n");
imx6q_enet_phy_init();
of_platform_populate(NULL, of_default_bus_match_table, NULL, parent);
imx_anatop_init();
cpu_is_imx6q() ? imx6q_pm_init() : imx6dl_pm_init();
imx6q_1588_init();
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 (of_init_opp_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)
{
/*
* WAIT mode is broken on TO 1.0 and 1.1, so there is no point
* to run cpuidle on them.
*/
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);
}
}
static void __init imx6q_map_io(void)
{
debug_ll_io_init();
imx_scu_map_io();
}
static void __init imx6q_init_irq(void)
{
imx_gpc_check_dt();
imx_init_revision_from_anatop();
imx_init_l2cache();
imx_src_init();
irqchip_init();
imx6_pm_ccm_init("fsl,imx6q-ccm");
}
static const char * const imx6q_dt_compat[] __initconst = {
"fsl,imx6dl",
"fsl,imx6q",
NULL,
};
DT_MACHINE_START(IMX6Q, "Freescale i.MX6 Quad/DualLite (Device Tree)")
.smp = smp_ops(imx_smp_ops),
.map_io = imx6q_map_io,
.init_irq = imx6q_init_irq,
.init_machine = imx6q_init_machine,
.init_late = imx6q_init_late,
.dt_compat = imx6q_dt_compat,
MACHINE_END
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