On Saturday 14 July 2012 05:46 AM, Mike Turquette wrote:
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<mturque...@linaro.org>
---
drivers/cpufreq/omap-cpufreq.c | 154 +++++++++++++++++++++++++---------------
1 file changed, 96 insertions(+), 58 deletions(-)
<snip>
-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;
+ }
}
How are you checking pre and post rate change condition here? Need
switch case for event?
+ return NOTIFY_OK;
+}
+
+static struct notifier_block mpu_clk_volt_scale_nb = {
+ .notifier_call = mpu_clk_volt_scale_handler,
+};
+
+
--
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