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linux-next/drivers/soc/qcom/spm.c
Stephen Boyd 498f09bce4 soc: qcom: spm: Fix idle on THUMB2 kernels
The ifc6410 firmware always enters the kernel in ARM state from
deep idle. Use the cpu_resume_arm() wrapper instead of
cpu_resume() to property switch into the THUMB2 state when we
wake up from idle.

This fixes a problem reported by Kevin Hilman on next-20150601
where the ifc6410 fails to boot a THUMB2 kernel because the
platform's firmware always enters the kernel in ARM mode from
deep idle states.

Reported-by: Kevin Hilman <khilman@linaro.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Lina Iyer <lina.iyer@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Kevin Hilman <khilman@linaro.org>
2015-07-01 12:16:30 -07:00

386 lines
9.6 KiB
C

/*
* Copyright (c) 2011-2014, The Linux Foundation. All rights reserved.
* Copyright (c) 2014,2015, Linaro Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/cpuidle.h>
#include <linux/cpu_pm.h>
#include <linux/qcom_scm.h>
#include <asm/cpuidle.h>
#include <asm/proc-fns.h>
#include <asm/suspend.h>
#define MAX_PMIC_DATA 2
#define MAX_SEQ_DATA 64
#define SPM_CTL_INDEX 0x7f
#define SPM_CTL_INDEX_SHIFT 4
#define SPM_CTL_EN BIT(0)
enum pm_sleep_mode {
PM_SLEEP_MODE_STBY,
PM_SLEEP_MODE_RET,
PM_SLEEP_MODE_SPC,
PM_SLEEP_MODE_PC,
PM_SLEEP_MODE_NR,
};
enum spm_reg {
SPM_REG_CFG,
SPM_REG_SPM_CTL,
SPM_REG_DLY,
SPM_REG_PMIC_DLY,
SPM_REG_PMIC_DATA_0,
SPM_REG_PMIC_DATA_1,
SPM_REG_VCTL,
SPM_REG_SEQ_ENTRY,
SPM_REG_SPM_STS,
SPM_REG_PMIC_STS,
SPM_REG_NR,
};
struct spm_reg_data {
const u8 *reg_offset;
u32 spm_cfg;
u32 spm_dly;
u32 pmic_dly;
u32 pmic_data[MAX_PMIC_DATA];
u8 seq[MAX_SEQ_DATA];
u8 start_index[PM_SLEEP_MODE_NR];
};
struct spm_driver_data {
void __iomem *reg_base;
const struct spm_reg_data *reg_data;
};
static const u8 spm_reg_offset_v2_1[SPM_REG_NR] = {
[SPM_REG_CFG] = 0x08,
[SPM_REG_SPM_CTL] = 0x30,
[SPM_REG_DLY] = 0x34,
[SPM_REG_SEQ_ENTRY] = 0x80,
};
/* SPM register data for 8974, 8084 */
static const struct spm_reg_data spm_reg_8974_8084_cpu = {
.reg_offset = spm_reg_offset_v2_1,
.spm_cfg = 0x1,
.spm_dly = 0x3C102800,
.seq = { 0x03, 0x0B, 0x0F, 0x00, 0x20, 0x80, 0x10, 0xE8, 0x5B, 0x03,
0x3B, 0xE8, 0x5B, 0x82, 0x10, 0x0B, 0x30, 0x06, 0x26, 0x30,
0x0F },
.start_index[PM_SLEEP_MODE_STBY] = 0,
.start_index[PM_SLEEP_MODE_SPC] = 3,
};
static const u8 spm_reg_offset_v1_1[SPM_REG_NR] = {
[SPM_REG_CFG] = 0x08,
[SPM_REG_SPM_CTL] = 0x20,
[SPM_REG_PMIC_DLY] = 0x24,
[SPM_REG_PMIC_DATA_0] = 0x28,
[SPM_REG_PMIC_DATA_1] = 0x2C,
[SPM_REG_SEQ_ENTRY] = 0x80,
};
/* SPM register data for 8064 */
static const struct spm_reg_data spm_reg_8064_cpu = {
.reg_offset = spm_reg_offset_v1_1,
.spm_cfg = 0x1F,
.pmic_dly = 0x02020004,
.pmic_data[0] = 0x0084009C,
.pmic_data[1] = 0x00A4001C,
.seq = { 0x03, 0x0F, 0x00, 0x24, 0x54, 0x10, 0x09, 0x03, 0x01,
0x10, 0x54, 0x30, 0x0C, 0x24, 0x30, 0x0F },
.start_index[PM_SLEEP_MODE_STBY] = 0,
.start_index[PM_SLEEP_MODE_SPC] = 2,
};
static DEFINE_PER_CPU(struct spm_driver_data *, cpu_spm_drv);
typedef int (*idle_fn)(int);
static DEFINE_PER_CPU(idle_fn*, qcom_idle_ops);
static inline void spm_register_write(struct spm_driver_data *drv,
enum spm_reg reg, u32 val)
{
if (drv->reg_data->reg_offset[reg])
writel_relaxed(val, drv->reg_base +
drv->reg_data->reg_offset[reg]);
}
/* Ensure a guaranteed write, before return */
static inline void spm_register_write_sync(struct spm_driver_data *drv,
enum spm_reg reg, u32 val)
{
u32 ret;
if (!drv->reg_data->reg_offset[reg])
return;
do {
writel_relaxed(val, drv->reg_base +
drv->reg_data->reg_offset[reg]);
ret = readl_relaxed(drv->reg_base +
drv->reg_data->reg_offset[reg]);
if (ret == val)
break;
cpu_relax();
} while (1);
}
static inline u32 spm_register_read(struct spm_driver_data *drv,
enum spm_reg reg)
{
return readl_relaxed(drv->reg_base + drv->reg_data->reg_offset[reg]);
}
static void spm_set_low_power_mode(struct spm_driver_data *drv,
enum pm_sleep_mode mode)
{
u32 start_index;
u32 ctl_val;
start_index = drv->reg_data->start_index[mode];
ctl_val = spm_register_read(drv, SPM_REG_SPM_CTL);
ctl_val &= ~(SPM_CTL_INDEX << SPM_CTL_INDEX_SHIFT);
ctl_val |= start_index << SPM_CTL_INDEX_SHIFT;
ctl_val |= SPM_CTL_EN;
spm_register_write_sync(drv, SPM_REG_SPM_CTL, ctl_val);
}
static int qcom_pm_collapse(unsigned long int unused)
{
qcom_scm_cpu_power_down(QCOM_SCM_CPU_PWR_DOWN_L2_ON);
/*
* Returns here only if there was a pending interrupt and we did not
* power down as a result.
*/
return -1;
}
static int qcom_cpu_spc(int cpu)
{
int ret;
struct spm_driver_data *drv = per_cpu(cpu_spm_drv, cpu);
spm_set_low_power_mode(drv, PM_SLEEP_MODE_SPC);
ret = cpu_suspend(0, qcom_pm_collapse);
/*
* ARM common code executes WFI without calling into our driver and
* if the SPM mode is not reset, then we may accidently power down the
* cpu when we intended only to gate the cpu clock.
* Ensure the state is set to standby before returning.
*/
spm_set_low_power_mode(drv, PM_SLEEP_MODE_STBY);
return ret;
}
static int qcom_idle_enter(int cpu, unsigned long index)
{
return per_cpu(qcom_idle_ops, cpu)[index](cpu);
}
static const struct of_device_id qcom_idle_state_match[] __initconst = {
{ .compatible = "qcom,idle-state-spc", .data = qcom_cpu_spc },
{ },
};
static int __init qcom_cpuidle_init(struct device_node *cpu_node, int cpu)
{
const struct of_device_id *match_id;
struct device_node *state_node;
int i;
int state_count = 1;
idle_fn idle_fns[CPUIDLE_STATE_MAX];
idle_fn *fns;
cpumask_t mask;
bool use_scm_power_down = false;
for (i = 0; ; i++) {
state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);
if (!state_node)
break;
if (!of_device_is_available(state_node))
continue;
if (i == CPUIDLE_STATE_MAX) {
pr_warn("%s: cpuidle states reached max possible\n",
__func__);
break;
}
match_id = of_match_node(qcom_idle_state_match, state_node);
if (!match_id)
return -ENODEV;
idle_fns[state_count] = match_id->data;
/* Check if any of the states allow power down */
if (match_id->data == qcom_cpu_spc)
use_scm_power_down = true;
state_count++;
}
if (state_count == 1)
goto check_spm;
fns = devm_kcalloc(get_cpu_device(cpu), state_count, sizeof(*fns),
GFP_KERNEL);
if (!fns)
return -ENOMEM;
for (i = 1; i < state_count; i++)
fns[i] = idle_fns[i];
if (use_scm_power_down) {
/* We have atleast one power down mode */
cpumask_clear(&mask);
cpumask_set_cpu(cpu, &mask);
qcom_scm_set_warm_boot_addr(cpu_resume_arm, &mask);
}
per_cpu(qcom_idle_ops, cpu) = fns;
/*
* SPM probe for the cpu should have happened by now, if the
* SPM device does not exist, return -ENXIO to indicate that the
* cpu does not support idle states.
*/
check_spm:
return per_cpu(cpu_spm_drv, cpu) ? 0 : -ENXIO;
}
static struct cpuidle_ops qcom_cpuidle_ops __initdata = {
.suspend = qcom_idle_enter,
.init = qcom_cpuidle_init,
};
CPUIDLE_METHOD_OF_DECLARE(qcom_idle_v1, "qcom,kpss-acc-v1", &qcom_cpuidle_ops);
CPUIDLE_METHOD_OF_DECLARE(qcom_idle_v2, "qcom,kpss-acc-v2", &qcom_cpuidle_ops);
static struct spm_driver_data *spm_get_drv(struct platform_device *pdev,
int *spm_cpu)
{
struct spm_driver_data *drv = NULL;
struct device_node *cpu_node, *saw_node;
int cpu;
bool found;
for_each_possible_cpu(cpu) {
cpu_node = of_cpu_device_node_get(cpu);
if (!cpu_node)
continue;
saw_node = of_parse_phandle(cpu_node, "qcom,saw", 0);
found = (saw_node == pdev->dev.of_node);
of_node_put(saw_node);
of_node_put(cpu_node);
if (found)
break;
}
if (found) {
drv = devm_kzalloc(&pdev->dev, sizeof(*drv), GFP_KERNEL);
if (drv)
*spm_cpu = cpu;
}
return drv;
}
static const struct of_device_id spm_match_table[] = {
{ .compatible = "qcom,msm8974-saw2-v2.1-cpu",
.data = &spm_reg_8974_8084_cpu },
{ .compatible = "qcom,apq8084-saw2-v2.1-cpu",
.data = &spm_reg_8974_8084_cpu },
{ .compatible = "qcom,apq8064-saw2-v1.1-cpu",
.data = &spm_reg_8064_cpu },
{ },
};
static int spm_dev_probe(struct platform_device *pdev)
{
struct spm_driver_data *drv;
struct resource *res;
const struct of_device_id *match_id;
void __iomem *addr;
int cpu;
drv = spm_get_drv(pdev, &cpu);
if (!drv)
return -EINVAL;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
drv->reg_base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(drv->reg_base))
return PTR_ERR(drv->reg_base);
match_id = of_match_node(spm_match_table, pdev->dev.of_node);
if (!match_id)
return -ENODEV;
drv->reg_data = match_id->data;
/* Write the SPM sequences first.. */
addr = drv->reg_base + drv->reg_data->reg_offset[SPM_REG_SEQ_ENTRY];
__iowrite32_copy(addr, drv->reg_data->seq,
ARRAY_SIZE(drv->reg_data->seq) / 4);
/*
* ..and then the control registers.
* On some SoC if the control registers are written first and if the
* CPU was held in reset, the reset signal could trigger the SPM state
* machine, before the sequences are completely written.
*/
spm_register_write(drv, SPM_REG_CFG, drv->reg_data->spm_cfg);
spm_register_write(drv, SPM_REG_DLY, drv->reg_data->spm_dly);
spm_register_write(drv, SPM_REG_PMIC_DLY, drv->reg_data->pmic_dly);
spm_register_write(drv, SPM_REG_PMIC_DATA_0,
drv->reg_data->pmic_data[0]);
spm_register_write(drv, SPM_REG_PMIC_DATA_1,
drv->reg_data->pmic_data[1]);
/* Set up Standby as the default low power mode */
spm_set_low_power_mode(drv, PM_SLEEP_MODE_STBY);
per_cpu(cpu_spm_drv, cpu) = drv;
return 0;
}
static struct platform_driver spm_driver = {
.probe = spm_dev_probe,
.driver = {
.name = "saw",
.of_match_table = spm_match_table,
},
};
module_platform_driver(spm_driver);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("SAW power controller driver");
MODULE_ALIAS("platform:saw");