RPMH based targets require that the next wake-up timer value needs
to be programmed to PDC (Power Domain Controller) which has its
own timer and is in an always on power domain. PDC wakes-up
the RSC and sets up the resources back in active state before the
processor is woken up by a timer interrupt.
Signed-off-by: Raju P.L.S.S.S.N <rplsssn@xxxxxxxxxxxxxx>
---
drivers/soc/qcom/Kconfig | 9 ++
drivers/soc/qcom/Makefile | 1 +
drivers/soc/qcom/rpmh-pdc-timer.c | 181 ++++++++++++++++++++++++++++++
3 files changed, 191 insertions(+)
create mode 100644 drivers/soc/qcom/rpmh-pdc-timer.c
diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
index 684cb51694d1..d04724ea5490 100644
--- a/drivers/soc/qcom/Kconfig
+++ b/drivers/soc/qcom/Kconfig
@@ -103,6 +103,15 @@ config QCOM_RPMH
of hardware components aggregate requests for these resources and
help apply the aggregated state on the resource.
+config QCOM_RPMH_PDC_TIMER
+ bool "Qualcomm PDC Timer for RPM-Hardened based SoCs"
+ depends on CPU_PM
+ help
+ Support for QCOM platform next wakeup timer programming when
+ application processor enters SoC level deepest low power mode.
+ The wakeup is programmed to PDC (Power Domain Controller)
+ timer which is in always on power domain.
+
config QCOM_SMEM
tristate "Qualcomm Shared Memory Manager (SMEM)"
depends on ARCH_QCOM || COMPILE_TEST
diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index f25b54cd6cf8..2ddb7e4f9098 100644
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -12,6 +12,7 @@ obj-$(CONFIG_QCOM_RMTFS_MEM) += rmtfs_mem.o
obj-$(CONFIG_QCOM_RPMH) += qcom_rpmh.o
qcom_rpmh-y += rpmh-rsc.o
qcom_rpmh-y += rpmh.o
+obj-$(CONFIG_QCOM_RPMH_PDC_TIMER) += rpmh-pdc-timer.o
obj-$(CONFIG_QCOM_SMD_RPM) += smd-rpm.o
obj-$(CONFIG_QCOM_SMEM) += smem.o
obj-$(CONFIG_QCOM_SMEM_STATE) += smem_state.o
diff --git a/drivers/soc/qcom/rpmh-pdc-timer.c b/drivers/soc/qcom/rpmh-pdc-timer.c
new file mode 100644
index 000000000000..108ea4a2df89
--- /dev/null
+++ b/drivers/soc/qcom/rpmh-pdc-timer.c
@@ -0,0 +1,181 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/cpu_pm.h>
+#include <linux/kernel.h>
+#include <linux/ktime.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/tick.h>
+#include <asm/arch_timer.h>
+
+#include <soc/qcom/rpmh.h>
+
+#define ARCH_TIMER_HZ (19200000)
+#define PDC_TIME_VALID_SHIFT 31
+#define PDC_TIME_UPPER_MASK 0xFFFFFF
+
+static struct regmap *rsc_regmap;
+static resource_size_t cmd0_data_offset;
+static resource_size_t cmd1_data_offset;
+static uint64_t pdc_wakeup = ~0ULL;
+static raw_spinlock_t pdc_wakeup_lock;
+
+/* convert micro sec to ticks or clock cycles
+ *
+ * time in cycles = (time in sec) * Freq
+ * = (time in sec) * 19200000
+ *
+ * However, while converting micro sec to sec,
+ * there is a possibility of round of errors.
+ * So round of errors are minimized by finding
+ * nano sec.
+ */
+static uint64_t us_to_cycles(uint64_t time_us)
+{
+ uint64_t sec, nsec, time_cycles;
+
+ sec = time_us;
+ do_div(sec, USEC_PER_SEC);
+ nsec = time_us - sec * USEC_PER_SEC;
+
+ if (nsec > 0) {
+ nsec = nsec * NSEC_PER_USEC;
+ do_div(nsec, NSEC_PER_SEC);
+ }
+
+ sec += nsec;
+
+ time_cycles = (u64)sec * ARCH_TIMER_HZ;
+
+ return time_cycles;
+}
+
+/*
+ * Find next wakeup of a cpu and convert into
+ * cycles.
+ */
+static uint64_t get_next_wakeup_cycles(int cpu)
+{
+ ktime_t next_wakeup;
+ uint64_t next_wakeup_cycles;
+
+ next_wakeup = tick_nohz_get_next_wakeup(cpu);
+
+ /*
+ * Find the relative wakeup from current time
+ * in kernel time scale
+ */
+ next_wakeup = ktime_sub(next_wakeup, ktime_get());
+
+ next_wakeup_cycles = us_to_cycles(ktime_to_us(next_wakeup));
+
+ /*
+ * Add current time in arch timer scale.
+ * This is needed as PDC match value is programmed
+ * with absolute value, not the relative value
+ * from current time
+ */
+ next_wakeup_cycles += arch_counter_get_cntvct();
+
+ return next_wakeup_cycles;
+}
+
+static void setup_pdc_wakeup_timer(uint64_t wakeup_cycles)
+{
+ u32 data0, data1;
+
+ data0 = (wakeup_cycles >> 32) & PDC_TIME_UPPER_MASK;
+ data0 |= 1 << PDC_TIME_VALID_SHIFT;
+ data1 = (wakeup_cycles & 0xFFFFFFFF);
+
+ regmap_write(rsc_regmap, cmd0_data_offset, data0);
+ regmap_write(rsc_regmap, cmd1_data_offset, data1);
+
+}
+
+static int cpu_pm_notifier(struct notifier_block *b,
+ unsigned long cmd, void *v)
+{
+ uint64_t cpu_next_wakeup;
+
+ switch (cmd) {
+ case CPU_PM_ENTER:
+ cpu_next_wakeup = get_next_wakeup_cycles(smp_processor_id());
+ raw_spin_lock(&pdc_wakeup_lock);
+ /*
+ * If PDC wakeup is expired or
+ * If current cpu next wakeup is early,
+ * program the same to pdc wakeup
+ */
+ if ((pdc_wakeup < arch_counter_get_cntvct()) ||
+ (cpu_next_wakeup < pdc_wakeup)) {
+ pdc_wakeup = cpu_next_wakeup;
+ setup_pdc_wakeup_timer(pdc_wakeup);
+ }
+ raw_spin_unlock(&pdc_wakeup_lock);
+ break;
+ default:
+ return NOTIFY_DONE;
+ }
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block cpu_pm_notifier_block = {
+ .notifier_call = cpu_pm_notifier,
+ .priority = -1, /* Should be last in the order of notifications */
+};
+
+static int pdc_timer_probe(struct platform_device *pdev)
+{
+ struct device *pdc_timer_dev = &pdev->dev;
+ struct resource *res = NULL;
+
+ if (IS_ERR_OR_NULL(pdc_timer_dev)) {
+ pr_err("%s fail\n", __func__);
+ return PTR_ERR(pdc_timer_dev);
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ pr_err("res not found\n");
+ return -ENODEV;
+ }
+ cmd0_data_offset = res->start;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+ if (!res) {
+ pr_err("res not found\n");
+ return -ENODEV;
+ }
+ cmd1_data_offset = res->start;
+
+ rsc_regmap = dev_get_regmap(pdc_timer_dev->parent, NULL);
+ if (!rsc_regmap) {
+ pr_err("regmap for parent is not found\n");
+ return -ENODEV;
+ }
+
+ raw_spin_lock_init(&pdc_wakeup_lock);
+ cpu_pm_register_notifier(&cpu_pm_notifier_block);
+
+ return 0;
+}
+
+static const struct of_device_id pdc_timer_drv_match[] = {
+ { .compatible = "qcom,pdc-timer", },
+ { }
+};
+
+static struct platform_driver pdc_timer_driver = {
+ .probe = pdc_timer_probe,
+ .driver = {
+ .name = KBUILD_MODNAME,
+ .of_match_table = pdc_timer_drv_match,
+ },
+};
+builtin_platform_driver(pdc_timer_driver);
--
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