linux/drivers/cpufreq/imx6q-cpufreq.c
Fabio Estevam 2b3d58a3ad cpufreq: imx6q: Move speed grading check to cpufreq driver
On some i.MX6 SoCs (like i.MX6SL, i.MX6SX and i.MX6UL) that do not have
speed grading check, opp table will not be created in platform code,
so cpufreq driver prints the following error message:

cpu cpu0: dev_pm_opp_get_opp_count: OPP table not found (-19)

However, this is not really an error in this case because the
imx6q-cpufreq driver first calls dev_pm_opp_get_opp_count()
and if it fails, it means that platform code does not provide
OPP and then dev_pm_opp_of_add_table() will be called.

In order to avoid such confusing error message, move the speed grading
check from platform code to the imx6q-cpufreq driver.

This way the imx6q-cpufreq no longer has to check whether OPP table
is supplied by platform code.

Tested on a i.MX6Q and i.MX6UL based boards.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-10-11 01:56:25 +02:00

478 lines
13 KiB
C

/*
* Copyright (C) 2013 Freescale Semiconductor, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/clk.h>
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/pm_opp.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#define PU_SOC_VOLTAGE_NORMAL 1250000
#define PU_SOC_VOLTAGE_HIGH 1275000
#define FREQ_1P2_GHZ 1200000000
static struct regulator *arm_reg;
static struct regulator *pu_reg;
static struct regulator *soc_reg;
static struct clk *arm_clk;
static struct clk *pll1_sys_clk;
static struct clk *pll1_sw_clk;
static struct clk *step_clk;
static struct clk *pll2_pfd2_396m_clk;
/* clk used by i.MX6UL */
static struct clk *pll2_bus_clk;
static struct clk *secondary_sel_clk;
static struct device *cpu_dev;
static bool free_opp;
static struct cpufreq_frequency_table *freq_table;
static unsigned int transition_latency;
static u32 *imx6_soc_volt;
static u32 soc_opp_count;
static int imx6q_set_target(struct cpufreq_policy *policy, unsigned int index)
{
struct dev_pm_opp *opp;
unsigned long freq_hz, volt, volt_old;
unsigned int old_freq, new_freq;
bool pll1_sys_temp_enabled = false;
int ret;
new_freq = freq_table[index].frequency;
freq_hz = new_freq * 1000;
old_freq = clk_get_rate(arm_clk) / 1000;
opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_hz);
if (IS_ERR(opp)) {
dev_err(cpu_dev, "failed to find OPP for %ld\n", freq_hz);
return PTR_ERR(opp);
}
volt = dev_pm_opp_get_voltage(opp);
dev_pm_opp_put(opp);
volt_old = regulator_get_voltage(arm_reg);
dev_dbg(cpu_dev, "%u MHz, %ld mV --> %u MHz, %ld mV\n",
old_freq / 1000, volt_old / 1000,
new_freq / 1000, volt / 1000);
/* scaling up? scale voltage before frequency */
if (new_freq > old_freq) {
if (!IS_ERR(pu_reg)) {
ret = regulator_set_voltage_tol(pu_reg, imx6_soc_volt[index], 0);
if (ret) {
dev_err(cpu_dev, "failed to scale vddpu up: %d\n", ret);
return ret;
}
}
ret = regulator_set_voltage_tol(soc_reg, imx6_soc_volt[index], 0);
if (ret) {
dev_err(cpu_dev, "failed to scale vddsoc up: %d\n", ret);
return ret;
}
ret = regulator_set_voltage_tol(arm_reg, volt, 0);
if (ret) {
dev_err(cpu_dev,
"failed to scale vddarm up: %d\n", ret);
return ret;
}
}
/*
* The setpoints are selected per PLL/PDF frequencies, so we need to
* reprogram PLL for frequency scaling. The procedure of reprogramming
* PLL1 is as below.
* For i.MX6UL, it has a secondary clk mux, the cpu frequency change
* flow is slightly different from other i.MX6 OSC.
* The cpu frequeny change flow for i.MX6(except i.MX6UL) is as below:
* - Enable pll2_pfd2_396m_clk and reparent pll1_sw_clk to it
* - Reprogram pll1_sys_clk and reparent pll1_sw_clk back to it
* - Disable pll2_pfd2_396m_clk
*/
if (of_machine_is_compatible("fsl,imx6ul") ||
of_machine_is_compatible("fsl,imx6ull")) {
/*
* When changing pll1_sw_clk's parent to pll1_sys_clk,
* CPU may run at higher than 528MHz, this will lead to
* the system unstable if the voltage is lower than the
* voltage of 528MHz, so lower the CPU frequency to one
* half before changing CPU frequency.
*/
clk_set_rate(arm_clk, (old_freq >> 1) * 1000);
clk_set_parent(pll1_sw_clk, pll1_sys_clk);
if (freq_hz > clk_get_rate(pll2_pfd2_396m_clk))
clk_set_parent(secondary_sel_clk, pll2_bus_clk);
else
clk_set_parent(secondary_sel_clk, pll2_pfd2_396m_clk);
clk_set_parent(step_clk, secondary_sel_clk);
clk_set_parent(pll1_sw_clk, step_clk);
} else {
clk_set_parent(step_clk, pll2_pfd2_396m_clk);
clk_set_parent(pll1_sw_clk, step_clk);
if (freq_hz > clk_get_rate(pll2_pfd2_396m_clk)) {
clk_set_rate(pll1_sys_clk, new_freq * 1000);
clk_set_parent(pll1_sw_clk, pll1_sys_clk);
} else {
/* pll1_sys needs to be enabled for divider rate change to work. */
pll1_sys_temp_enabled = true;
clk_prepare_enable(pll1_sys_clk);
}
}
/* Ensure the arm clock divider is what we expect */
ret = clk_set_rate(arm_clk, new_freq * 1000);
if (ret) {
dev_err(cpu_dev, "failed to set clock rate: %d\n", ret);
regulator_set_voltage_tol(arm_reg, volt_old, 0);
return ret;
}
/* PLL1 is only needed until after ARM-PODF is set. */
if (pll1_sys_temp_enabled)
clk_disable_unprepare(pll1_sys_clk);
/* scaling down? scale voltage after frequency */
if (new_freq < old_freq) {
ret = regulator_set_voltage_tol(arm_reg, volt, 0);
if (ret) {
dev_warn(cpu_dev,
"failed to scale vddarm down: %d\n", ret);
ret = 0;
}
ret = regulator_set_voltage_tol(soc_reg, imx6_soc_volt[index], 0);
if (ret) {
dev_warn(cpu_dev, "failed to scale vddsoc down: %d\n", ret);
ret = 0;
}
if (!IS_ERR(pu_reg)) {
ret = regulator_set_voltage_tol(pu_reg, imx6_soc_volt[index], 0);
if (ret) {
dev_warn(cpu_dev, "failed to scale vddpu down: %d\n", ret);
ret = 0;
}
}
}
return 0;
}
static int imx6q_cpufreq_init(struct cpufreq_policy *policy)
{
int ret;
policy->clk = arm_clk;
ret = cpufreq_generic_init(policy, freq_table, transition_latency);
policy->suspend_freq = policy->max;
return ret;
}
static struct cpufreq_driver imx6q_cpufreq_driver = {
.flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK,
.verify = cpufreq_generic_frequency_table_verify,
.target_index = imx6q_set_target,
.get = cpufreq_generic_get,
.init = imx6q_cpufreq_init,
.name = "imx6q-cpufreq",
.attr = cpufreq_generic_attr,
.suspend = cpufreq_generic_suspend,
};
#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 imx6q_opp_check_speed_grading(struct device *dev)
{
struct device_node *np;
void __iomem *base;
u32 val;
np = of_find_compatible_node(NULL, NULL, "fsl,imx6q-ocotp");
if (!np)
return;
base = of_iomap(np, 0);
if (!base) {
dev_err(dev, "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) &&
of_machine_is_compatible("fsl,imx6q"))
if (dev_pm_opp_disable(dev, 1200000000))
dev_warn(dev, "failed to disable 1.2GHz OPP\n");
if (val < OCOTP_CFG3_SPEED_996MHZ)
if (dev_pm_opp_disable(dev, 996000000))
dev_warn(dev, "failed to disable 996MHz OPP\n");
if (of_machine_is_compatible("fsl,imx6q")) {
if (val != OCOTP_CFG3_SPEED_852MHZ)
if (dev_pm_opp_disable(dev, 852000000))
dev_warn(dev, "failed to disable 852MHz OPP\n");
}
iounmap(base);
put_node:
of_node_put(np);
}
static int imx6q_cpufreq_probe(struct platform_device *pdev)
{
struct device_node *np;
struct dev_pm_opp *opp;
unsigned long min_volt, max_volt;
int num, ret;
const struct property *prop;
const __be32 *val;
u32 nr, i, j;
cpu_dev = get_cpu_device(0);
if (!cpu_dev) {
pr_err("failed to get cpu0 device\n");
return -ENODEV;
}
np = of_node_get(cpu_dev->of_node);
if (!np) {
dev_err(cpu_dev, "failed to find cpu0 node\n");
return -ENOENT;
}
arm_clk = clk_get(cpu_dev, "arm");
pll1_sys_clk = clk_get(cpu_dev, "pll1_sys");
pll1_sw_clk = clk_get(cpu_dev, "pll1_sw");
step_clk = clk_get(cpu_dev, "step");
pll2_pfd2_396m_clk = clk_get(cpu_dev, "pll2_pfd2_396m");
if (IS_ERR(arm_clk) || IS_ERR(pll1_sys_clk) || IS_ERR(pll1_sw_clk) ||
IS_ERR(step_clk) || IS_ERR(pll2_pfd2_396m_clk)) {
dev_err(cpu_dev, "failed to get clocks\n");
ret = -ENOENT;
goto put_clk;
}
if (of_machine_is_compatible("fsl,imx6ul") ||
of_machine_is_compatible("fsl,imx6ull")) {
pll2_bus_clk = clk_get(cpu_dev, "pll2_bus");
secondary_sel_clk = clk_get(cpu_dev, "secondary_sel");
if (IS_ERR(pll2_bus_clk) || IS_ERR(secondary_sel_clk)) {
dev_err(cpu_dev, "failed to get clocks specific to imx6ul\n");
ret = -ENOENT;
goto put_clk;
}
}
arm_reg = regulator_get(cpu_dev, "arm");
pu_reg = regulator_get_optional(cpu_dev, "pu");
soc_reg = regulator_get(cpu_dev, "soc");
if (PTR_ERR(arm_reg) == -EPROBE_DEFER ||
PTR_ERR(soc_reg) == -EPROBE_DEFER ||
PTR_ERR(pu_reg) == -EPROBE_DEFER) {
ret = -EPROBE_DEFER;
dev_dbg(cpu_dev, "regulators not ready, defer\n");
goto put_reg;
}
if (IS_ERR(arm_reg) || IS_ERR(soc_reg)) {
dev_err(cpu_dev, "failed to get regulators\n");
ret = -ENOENT;
goto put_reg;
}
ret = dev_pm_opp_of_add_table(cpu_dev);
if (ret < 0) {
dev_err(cpu_dev, "failed to init OPP table: %d\n", ret);
goto put_reg;
}
imx6q_opp_check_speed_grading(cpu_dev);
/* Because we have added the OPPs here, we must free them */
free_opp = true;
num = dev_pm_opp_get_opp_count(cpu_dev);
if (num < 0) {
ret = num;
dev_err(cpu_dev, "no OPP table is found: %d\n", ret);
goto out_free_opp;
}
ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
if (ret) {
dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
goto out_free_opp;
}
/* Make imx6_soc_volt array's size same as arm opp number */
imx6_soc_volt = devm_kzalloc(cpu_dev, sizeof(*imx6_soc_volt) * num, GFP_KERNEL);
if (imx6_soc_volt == NULL) {
ret = -ENOMEM;
goto free_freq_table;
}
prop = of_find_property(np, "fsl,soc-operating-points", NULL);
if (!prop || !prop->value)
goto soc_opp_out;
/*
* Each OPP is a set of tuples consisting of frequency and
* voltage like <freq-kHz vol-uV>.
*/
nr = prop->length / sizeof(u32);
if (nr % 2 || (nr / 2) < num)
goto soc_opp_out;
for (j = 0; j < num; j++) {
val = prop->value;
for (i = 0; i < nr / 2; i++) {
unsigned long freq = be32_to_cpup(val++);
unsigned long volt = be32_to_cpup(val++);
if (freq_table[j].frequency == freq) {
imx6_soc_volt[soc_opp_count++] = volt;
break;
}
}
}
soc_opp_out:
/* use fixed soc opp volt if no valid soc opp info found in dtb */
if (soc_opp_count != num) {
dev_warn(cpu_dev, "can NOT find valid fsl,soc-operating-points property in dtb, use default value!\n");
for (j = 0; j < num; j++)
imx6_soc_volt[j] = PU_SOC_VOLTAGE_NORMAL;
if (freq_table[num - 1].frequency * 1000 == FREQ_1P2_GHZ)
imx6_soc_volt[num - 1] = PU_SOC_VOLTAGE_HIGH;
}
if (of_property_read_u32(np, "clock-latency", &transition_latency))
transition_latency = CPUFREQ_ETERNAL;
/*
* Calculate the ramp time for max voltage change in the
* VDDSOC and VDDPU regulators.
*/
ret = regulator_set_voltage_time(soc_reg, imx6_soc_volt[0], imx6_soc_volt[num - 1]);
if (ret > 0)
transition_latency += ret * 1000;
if (!IS_ERR(pu_reg)) {
ret = regulator_set_voltage_time(pu_reg, imx6_soc_volt[0], imx6_soc_volt[num - 1]);
if (ret > 0)
transition_latency += ret * 1000;
}
/*
* OPP is maintained in order of increasing frequency, and
* freq_table initialised from OPP is therefore sorted in the
* same order.
*/
opp = dev_pm_opp_find_freq_exact(cpu_dev,
freq_table[0].frequency * 1000, true);
min_volt = dev_pm_opp_get_voltage(opp);
dev_pm_opp_put(opp);
opp = dev_pm_opp_find_freq_exact(cpu_dev,
freq_table[--num].frequency * 1000, true);
max_volt = dev_pm_opp_get_voltage(opp);
dev_pm_opp_put(opp);
ret = regulator_set_voltage_time(arm_reg, min_volt, max_volt);
if (ret > 0)
transition_latency += ret * 1000;
ret = cpufreq_register_driver(&imx6q_cpufreq_driver);
if (ret) {
dev_err(cpu_dev, "failed register driver: %d\n", ret);
goto free_freq_table;
}
of_node_put(np);
return 0;
free_freq_table:
dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
out_free_opp:
if (free_opp)
dev_pm_opp_of_remove_table(cpu_dev);
put_reg:
if (!IS_ERR(arm_reg))
regulator_put(arm_reg);
if (!IS_ERR(pu_reg))
regulator_put(pu_reg);
if (!IS_ERR(soc_reg))
regulator_put(soc_reg);
put_clk:
if (!IS_ERR(arm_clk))
clk_put(arm_clk);
if (!IS_ERR(pll1_sys_clk))
clk_put(pll1_sys_clk);
if (!IS_ERR(pll1_sw_clk))
clk_put(pll1_sw_clk);
if (!IS_ERR(step_clk))
clk_put(step_clk);
if (!IS_ERR(pll2_pfd2_396m_clk))
clk_put(pll2_pfd2_396m_clk);
if (!IS_ERR(pll2_bus_clk))
clk_put(pll2_bus_clk);
if (!IS_ERR(secondary_sel_clk))
clk_put(secondary_sel_clk);
of_node_put(np);
return ret;
}
static int imx6q_cpufreq_remove(struct platform_device *pdev)
{
cpufreq_unregister_driver(&imx6q_cpufreq_driver);
dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
if (free_opp)
dev_pm_opp_of_remove_table(cpu_dev);
regulator_put(arm_reg);
if (!IS_ERR(pu_reg))
regulator_put(pu_reg);
regulator_put(soc_reg);
clk_put(arm_clk);
clk_put(pll1_sys_clk);
clk_put(pll1_sw_clk);
clk_put(step_clk);
clk_put(pll2_pfd2_396m_clk);
clk_put(pll2_bus_clk);
clk_put(secondary_sel_clk);
return 0;
}
static struct platform_driver imx6q_cpufreq_platdrv = {
.driver = {
.name = "imx6q-cpufreq",
},
.probe = imx6q_cpufreq_probe,
.remove = imx6q_cpufreq_remove,
};
module_platform_driver(imx6q_cpufreq_platdrv);
MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>");
MODULE_DESCRIPTION("Freescale i.MX6Q cpufreq driver");
MODULE_LICENSE("GPL");