Thread (25 messages) 25 messages, 8 authors, 2013-04-02
STALE4815d

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

From: Mike Turquette <hidden>
Date: 2013-02-28 04:51:04
Also in: lkml
Subsystem: cpu frequency scaling framework, the rest · Maintainers: "Rafael J. Wysocki", Viresh Kumar, Linus Torvalds

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 <redacted>
---
 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
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