[PATCH 3/5] cpufreq: omap: scale regulator from clk notifier

Mike Turquette
2013-02-28T04:51:04Z

This patch moves direct control of the MPU voltage regulator out of the
cpufreq driver .target callback and instead uses the common dvfs clk
rate-change notifier infrastructure.

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).

Signed-off-by: Mike Turquette <mturquette@linaro.org>
---
drivers/cpufreq/omap-cpufreq.c | 82 ++++++++++------------------------------
1 file changed, 20 insertions(+), 62 deletions(-)

diff --git a/drivers/cpufreq/omap-cpufreq.c b/drivers/cpufreq/omap-cpufreq.c
index 1f3417a..6bec1c4 100644
--- a/drivers/cpufreq/omap-cpufreq.c
+++ b/drivers/cpufreq/omap-cpufreq.c
@@ -37,7 +37,7 @@ static struct cpufreq_frequency_table *freq_table;
static atomic_t freq_table_users = ATOMIC_INIT(0);
static struct clk *mpu_clk;
static struct device *mpu_dev;
-static struct regulator *mpu_reg;
+static struct dvfs_info *di;

static int omap_verify_speed(struct cpufreq_policy *policy)
{
@@ -62,10 +62,9 @@ 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__,
@@ -109,50 +108,13 @@ static int omap_target(struct cpufreq_policy *policy,
}
freq = ret;

- 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);

-done:
/* notifiers */
for_each_cpu(i, policy->cpus) {
freqs.cpu = i;
@@ -172,10 +134,6 @@ static int __cpuinit omap_cpu_init(struct cpufreq_policy *policy)
{
int result = 0;

- mpu_clk = clk_get(NULL, "cpufreq_ck");
- if (IS_ERR(mpu_clk))
- return PTR_ERR(mpu_clk);
-
if (policy->cpu >= NR_CPUS) {
result = -EINVAL;
goto fail_ck;
@@ -253,34 +211,34 @@ static struct cpufreq_driver omap_driver = {

static int __init omap_cpufreq_init(void)
{
+ struct dvfs_info_init dii;
+
+ mpu_clk = clk_get(NULL, "cpufreq_ck");
+ if (IS_ERR(mpu_clk))
+ return PTR_ERR(mpu_clk);
+
mpu_dev = get_cpu_device(0);
if (!mpu_dev) {
pr_warning("%s: unable to get the mpu device\n", __func__);
return -EINVAL;
}

- 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;
- } else {
- /*
- * Ensure physical regulator is present.
- * (e.g. could be dummy regulator.)
- */
- if (regulator_get_voltage(mpu_reg) < 0) {
- pr_warn("%s: physical regulator not present for MPU\n",
+ dii.dev = mpu_dev;
+ dii.con_id = "cpufreq_ck";
+ dii.reg_id = "vcc";
+ dii.tol = OPP_TOLERANCE;
+
+ di = dvfs_clk_notifier_register(&dii);
+ if (IS_ERR(di))
+ pr_warning("%s: failed to register dvfs clk notifier\n",
__func__);
- regulator_put(mpu_reg);
- mpu_reg = NULL;
- }
- }

return cpufreq_register_driver(&omap_driver);
}

static void __exit omap_cpufreq_exit(void)
{
+ dvfs_clk_notifier_unregister(di);
cpufreq_unregister_driver(&omap_driver);
}

--
1.7.10.4