Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751227Ab3JSX4D (ORCPT ); Sat, 19 Oct 2013 19:56:03 -0400 Received: from smtp161.dfw.emailsrvr.com ([67.192.241.161]:42732 "EHLO smtp161.dfw.emailsrvr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750919Ab3JSX4A (ORCPT ); Sat, 19 Oct 2013 19:56:00 -0400 From: Mark Langsdorf To: linux-kernel@vger.kernel.org, cpufreq@vger.kernel.org, linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Mark Langsdorf Subject: [PATCH] cpufreq, highbank: enable ECME thermal notifications Date: Sat, 19 Oct 2013 18:54:49 -0500 Message-Id: <1382226889-11062-1-git-send-email-mark.langsdorf@calxeda.com> X-Mailer: git-send-email 1.8.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5070 Lines: 173 The ECME sends thermal messages with a maximum and minimum allowed frequency when the SoC status reaches certain trip points known to the ECME. Use a notifier function to capture those messages and pass them to a work-queued function that can trigger a policy re-evaluation by cpufreq, capping the allowable frequencies. The core of the policy adjusting code was taken from drivers/thermal/cpu_cooling.c. Signed-off-by: Mark Langsdorf --- drivers/cpufreq/highbank-cpufreq.c | 117 +++++++++++++++++++++++++++++++++++++ 1 file changed, 117 insertions(+) diff --git a/drivers/cpufreq/highbank-cpufreq.c b/drivers/cpufreq/highbank-cpufreq.c index b61b5a3..f0521d3 100644 --- a/drivers/cpufreq/highbank-cpufreq.c +++ b/drivers/cpufreq/highbank-cpufreq.c @@ -17,15 +17,32 @@ #include #include #include +#include #include #include #include #include +#include +#include #define HB_CPUFREQ_CHANGE_NOTE 0x80000001 +#define HB_CPUFREQ_HEALTH_NOTE 0x00001001 +#define HB_CPUFREQ_TPS_REPORT 1 #define HB_CPUFREQ_IPC_LEN 7 #define HB_CPUFREQ_VOLT_RETRIES 15 +#define NOTIFY_INVALID NULL + +struct hb_notify_device { + unsigned long max_freq; + unsigned long min_freq; + unsigned long thermal_state; + struct cpumask *allowed_cpus; +}; + +static struct hb_notify_device hb_records, *notify_device = NOTIFY_INVALID; +static struct work_struct hb_thermal_wq; + static int hb_voltage_change(unsigned int freq) { u32 msg[HB_CPUFREQ_IPC_LEN] = {HB_CPUFREQ_CHANGE_NOTE, freq / 1000000}; @@ -33,6 +50,89 @@ static int hb_voltage_change(unsigned int freq) return pl320_ipc_transmit(msg); } +static int hb_thermal_cpufreq_notify(struct notifier_block *nb, + unsigned long event, void *data) +{ + struct cpufreq_policy *policy = data; + unsigned long max_freq = 0, min_freq = 0; + + if (event != CPUFREQ_ADJUST || notify_device == NOTIFY_INVALID) + return 0; + + if (cpumask_test_cpu(policy->cpu, notify_device->allowed_cpus)) { + max_freq = notify_device->max_freq; + min_freq = notify_device->min_freq; + } + + /* Never exceed user_policy.max */ + if (max_freq > policy->user_policy.max) + max_freq = policy->user_policy.max; + if (min_freq < policy->user_policy.min) + min_freq = policy->user_policy.min; + + if ((policy->max != max_freq) || (policy->min != min_freq)) + cpufreq_verify_within_limits(policy, min_freq, max_freq); + + return 0; +} + +static struct notifier_block hb_thermal_cpufreq_nb = { + .notifier_call = hb_thermal_cpufreq_notify, +}; + +/* + * We can't call cpufreq_adjust_policy from inside a notifier, so + * do it from inside a workqueue + */ +static void hb_thermal_wq_task(struct work_struct *work) +{ + unsigned int cpuid; + struct cpumask *mask = hb_records.allowed_cpus; + + notify_device = &hb_records; + + for_each_cpu(cpuid, mask) { + struct cpufreq_policy policy; + if (cpufreq_get_policy(&policy, cpuid) == 0) { + cpufreq_update_policy(cpuid); + break; + } + } + notify_device = NOTIFY_INVALID; +} + +static int hb_thermal_tps_notify(struct notifier_block *nb, + unsigned long action, void *mailbox) +{ + unsigned long *data = (unsigned long *) mailbox; + + if ((action != HB_CPUFREQ_HEALTH_NOTE) && + (data[0] != HB_CPUFREQ_TPS_REPORT)) + return 0; + + /* + * If we're already at this thermal state, or if ECME isn't + * sending frequency data, there's nothing to do + */ + if ((hb_records.thermal_state == data[1]) || !data[2] || !data[3]) + return NOTIFY_DONE; + + hb_records.thermal_state = data[1]; + hb_records.min_freq = data[2]; + hb_records.max_freq = data[3]; + notify_device = &hb_records; + + schedule_work(&hb_thermal_wq); + + pr_warn("ECME TPS event: frequencies limited to %lu-%lu MHz\n", + hb_records.min_freq, hb_records.max_freq); + return NOTIFY_DONE; +} + +static struct notifier_block hb_thermal_tps_nb = { + .notifier_call = hb_thermal_tps_notify, +}; + static int hb_cpufreq_clk_notify(struct notifier_block *nb, unsigned long action, void *hclk) { @@ -100,6 +200,23 @@ static int hb_cpufreq_driver_init(void) goto out_put_node; } + /* + * Set up thermal state notifications from ECME, but continue + * running even if they don't work. + */ + ret = pl320_ipc_register_notifier(&hb_thermal_tps_nb); + if (!ret) { + ret = cpufreq_register_notifier(&hb_thermal_cpufreq_nb, + CPUFREQ_POLICY_NOTIFIER); + if (ret) + pl320_ipc_unregister_notifier(&hb_thermal_tps_nb); + else { + hb_records.allowed_cpus = (struct cpumask *) + cpu_possible_mask; + INIT_WORK(&hb_thermal_wq, hb_thermal_wq_task); + } + } + /* Instantiate cpufreq-cpu0 */ platform_device_register_full(&devinfo); -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/