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Message-ID: <1342225001-22962-3-git-send-email-mturquette@linaro.org>
Date: Fri, 13 Jul 2012 17:16:41 -0700
From: Mike Turquette <mturquette@...aro.org>
To: <linux-kernel@...r.kernel.org>
CC: <shawn.guo@...aro.org>, <linus.walleij@...aro.org>,
<rob.herring@...xeda.com>, <pdeschrijver@...dia.com>,
<pgaikwad@...dia.com>, <viresh.kumar@...aro.org>, <rnayak@...com>,
<paul@...an.com>, <broonie@...nsource.wolfsonmicro.com>,
<tglx@...utronix.de>, <ccross@...roid.com>,
<linux-arm-kernel@...ts.infradead.org>,
Mike Turquette <mturquette@...aro.org>
Subject: [PATCH 2/2] [RFC] cpufreq: omap: scale regulator from clk notifier
This patch moves direct control of the MPU voltage regulator out of the
cpufreq driver .target callback and instead puts that logic into a clock
rate change notifier callback.
The same frequency/voltage lookup via the OPP library is present, except
that the calls to regulator_set_voltage are done from the clock
framework instead of cpufreq.
Ideally it would be nice to reduce the .target callback for OMAP's
cpufreq driver to a simple call to clk_set_rate. For now there is still
some other stuff needed there (jiffies per loop, rounding the rate, etc
etc).
Not-signed-off-by: Mike Turquette <mturquette@...aro.org>
---
drivers/cpufreq/omap-cpufreq.c | 154 +++++++++++++++++++++++++---------------
1 file changed, 96 insertions(+), 58 deletions(-)
diff --git a/drivers/cpufreq/omap-cpufreq.c b/drivers/cpufreq/omap-cpufreq.c
index 17fa04d..bf15c49 100644
--- a/drivers/cpufreq/omap-cpufreq.c
+++ b/drivers/cpufreq/omap-cpufreq.c
@@ -80,10 +80,9 @@ static int omap_target(struct cpufreq_policy *policy,
unsigned int relation)
{
unsigned int i;
- int r, ret = 0;
+ int ret = 0;
struct cpufreq_freqs freqs;
- struct opp *opp;
- unsigned long freq, volt = 0, volt_old = 0, tol = 0;
+ unsigned long freq;
if (!freq_table) {
dev_err(mpu_dev, "%s: cpu%d: no freq table!\n", __func__,
@@ -119,47 +118,11 @@ static int omap_target(struct cpufreq_policy *policy,
freq = freqs.new * 1000;
- if (mpu_reg) {
- opp = opp_find_freq_ceil(mpu_dev, &freq);
- if (IS_ERR(opp)) {
- dev_err(mpu_dev, "%s: unable to find MPU OPP for %d\n",
- __func__, freqs.new);
- return -EINVAL;
- }
- volt = opp_get_voltage(opp);
- tol = volt * OPP_TOLERANCE / 100;
- volt_old = regulator_get_voltage(mpu_reg);
- }
-
- dev_dbg(mpu_dev, "cpufreq-omap: %u MHz, %ld mV --> %u MHz, %ld mV\n",
- freqs.old / 1000, volt_old ? volt_old / 1000 : -1,
- freqs.new / 1000, volt ? volt / 1000 : -1);
-
- /* scaling up? scale voltage before frequency */
- if (mpu_reg && (freqs.new > freqs.old)) {
- r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
- if (r < 0) {
- dev_warn(mpu_dev, "%s: unable to scale voltage up.\n",
- __func__);
- freqs.new = freqs.old;
- goto done;
- }
- }
+ dev_dbg(mpu_dev, "cpufreq-omap: %u MHz --> %u MHz\n",
+ freqs.old / 1000, freqs.new / 1000);
ret = clk_set_rate(mpu_clk, freqs.new * 1000);
- /* scaling down? scale voltage after frequency */
- if (mpu_reg && (freqs.new < freqs.old)) {
- r = regulator_set_voltage(mpu_reg, volt - tol, volt + tol);
- if (r < 0) {
- dev_warn(mpu_dev, "%s: unable to scale voltage down.\n",
- __func__);
- ret = clk_set_rate(mpu_clk, freqs.old * 1000);
- freqs.new = freqs.old;
- goto done;
- }
- }
-
freqs.new = omap_getspeed(policy->cpu);
#ifdef CONFIG_SMP
/*
@@ -187,7 +150,6 @@ static int omap_target(struct cpufreq_policy *policy,
freqs.new);
#endif
-done:
/* notifiers */
for_each_cpu(i, policy->cpus) {
freqs.cpu = i;
@@ -207,10 +169,6 @@ static int __cpuinit omap_cpu_init(struct cpufreq_policy *policy)
{
int result = 0;
- mpu_clk = clk_get(NULL, mpu_clk_name);
- if (IS_ERR(mpu_clk))
- return PTR_ERR(mpu_clk);
-
if (policy->cpu >= NR_CPUS) {
result = -EINVAL;
goto fail_ck;
@@ -284,32 +242,74 @@ static struct cpufreq_driver omap_driver = {
.attr = omap_cpufreq_attr,
};
-static int __init omap_cpufreq_init(void)
+static int mpu_clk_volt_scale_handler(struct notifier_block *nb,
+ unsigned long flags, void *data)
{
- if (cpu_is_omap24xx())
- mpu_clk_name = "virt_prcm_set";
- else if (cpu_is_omap34xx())
- mpu_clk_name = "dpll1_ck";
- else if (cpu_is_omap44xx())
- mpu_clk_name = "dpll_mpu_ck";
+ struct clk_notifier_data *cnd = data;
+ unsigned long tol;
+ int ret, volt_new, volt_old;
+ struct opp *opp;
- if (!mpu_clk_name) {
- pr_err("%s: unsupported Silicon?\n", __func__);
- return -EINVAL;
+ volt_old = regulator_get_voltage(mpu_reg);
+ opp = opp_find_freq_exact(mpu_dev, cnd->new_rate, true);
+ volt_new = opp_get_voltage(opp);
+
+ tol = volt_new * OPP_TOLERANCE / 100;
+
+ /* scaling up? scale voltage before frequency */
+ if (cnd->new_rate > cnd->old_rate) {
+ dev_dbg(mpu_dev, "cpufreq-omap: %d mV --> %d mV\n",
+ volt_old, volt_new);
+
+ ret = regulator_set_voltage(mpu_reg, volt_new - tol, volt_new + tol);
+
+ if (ret < 0) {
+ dev_warn(mpu_dev, "%s: unable to scale voltage up.\n",
+ __func__);
+ return NOTIFY_BAD;
+ }
+ }
+
+ /* scaling down? scale voltage after frequency */
+ if (cnd->new_rate < cnd->old_rate) {
+ dev_dbg(mpu_dev, "cpufreq-omap: %d mV --> %d mV\n",
+ volt_old, volt_new);
+
+ ret = regulator_set_voltage(mpu_reg, volt_new - tol, volt_new + tol);
+
+ if (ret< 0) {
+ dev_warn(mpu_dev, "%s: unable to scale voltage down.\n",
+ __func__);
+ return NOTIFY_BAD;
+ }
}
+ return NOTIFY_OK;
+}
+
+static struct notifier_block mpu_clk_volt_scale_nb = {
+ .notifier_call = mpu_clk_volt_scale_handler,
+};
+
+static int __init omap_regulator_init(void)
+{
+ int ret = 0;
+
mpu_dev = omap_device_get_by_hwmod_name("mpu");
if (!mpu_dev) {
pr_warning("%s: unable to get the mpu device\n", __func__);
- return -EINVAL;
+ ret = -EINVAL;
+ goto out;
}
mpu_reg = regulator_get(mpu_dev, "vcc");
if (IS_ERR(mpu_reg)) {
pr_warning("%s: unable to get MPU regulator\n", __func__);
mpu_reg = NULL;
+ ret = -ENODEV;
+ goto out;
} else {
- /*
+ /*
* Ensure physical regulator is present.
* (e.g. could be dummy regulator.)
*/
@@ -318,9 +318,47 @@ static int __init omap_cpufreq_init(void)
__func__);
regulator_put(mpu_reg);
mpu_reg = NULL;
+ ret = -ENODEV;
+ goto out;
}
}
+out:
+ return ret;
+}
+
+static int __init omap_cpufreq_init(void)
+{
+ int ret;
+
+ if (cpu_is_omap24xx())
+ mpu_clk_name = "virt_prcm_set";
+ else if (cpu_is_omap34xx())
+ mpu_clk_name = "dpll1_ck";
+ else if (cpu_is_omap44xx())
+ mpu_clk_name = "dpll_mpu_ck";
+
+ if (!mpu_clk_name) {
+ pr_err("%s: unsupported Silicon?\n", __func__);
+ return -EINVAL;
+ }
+
+ mpu_clk = clk_get(NULL, mpu_clk_name);
+ if (IS_ERR(mpu_clk))
+ return PTR_ERR(mpu_clk);
+
+ ret = omap_regulator_init();
+ if (ret) {
+ pr_err("%s: failed to get mpu regulator\n", __func__);
+ pr_err("%s: skipping clk notifier registration\n", __func__);
+ goto out;
+ }
+
+ ret = clk_notifier_register(mpu_clk, &mpu_clk_volt_scale_nb);
+ if (ret)
+ pr_err("%s: failed to register clk notifier\n", __func__);
+
+out:
return cpufreq_register_driver(&omap_driver);
}
--
1.7.9.5
--
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