[PATCH v14 03/10] qcom: spm: Add Subsystem Power Manager driver

Lina Iyer
2014-12-02T17:39:11Z

SPM is a hardware block that controls the peripheral logic surrounding
the application cores (cpu/l$). When the core executes WFI instruction,
the SPM takes over the putting the core in low power state as
configured. The wake up for the SPM is an interrupt at the GIC, which
then completes the rest of low power mode sequence and brings the core
out of low power mode.

The SPM has a set of control registers that configure the SPMs
individually based on the type of the core and the runtime conditions.
SPM is a finite state machine block to which a sequence is provided and
it interprets the bytes and executes them in sequence. Each low power
mode that the core can enter into is provided to the SPM as a sequence.

Configure the SPM to set the core (cpu or L2) into its low power mode,
the index of the first command in the sequence is set in the SPM_CTL
register. When the core executes ARM wfi instruction, it triggers the
SPM state machine to start executing from that index. The SPM state
machine waits until the interrupt occurs and starts executing the rest
of the sequence until it hits the end of the sequence. The end of the
sequence jumps the core out of its low power mode.

Add support for an idle driver to set up the SPM to place the core in
Standby or Standalone power collapse mode when the core is idle.

Based on work by: Mahesh Sivasubramanian <msivasub@codeaurora.org>,
Ai Li <ali@codeaurora.org>, Praveen Chidambaram <pchidamb@codeaurora.org>
Original tree available at -
git://codeaurora.org/quic/la/kernel/msm-3.10.git

Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
---
.../devicetree/bindings/arm/msm/qcom,saw2.txt | 31 +-
drivers/soc/qcom/Kconfig | 8 +
drivers/soc/qcom/Makefile | 1 +
drivers/soc/qcom/spm.c | 338 +++++++++++++++++++++
include/soc/qcom/pm.h | 31 ++
5 files changed, 403 insertions(+), 6 deletions(-)
create mode 100644 drivers/soc/qcom/spm.c
create mode 100644 include/soc/qcom/pm.h

diff --git a/Documentation/devicetree/bindings/arm/msm/qcom,saw2.txt b/Documentation/devicetree/bindings/arm/msm/qcom,saw2.txt
index 1505fb8..690c3c0 100644
--- a/Documentation/devicetree/bindings/arm/msm/qcom,saw2.txt
+++ b/Documentation/devicetree/bindings/arm/msm/qcom,saw2.txt
@@ -2,11 +2,20 @@ SPM AVS Wrapper 2 (SAW2)

The SAW2 is a wrapper around the Subsystem Power Manager (SPM) and the
Adaptive Voltage Scaling (AVS) hardware. The SPM is a programmable
-micro-controller that transitions a piece of hardware (like a processor or
+power-controller that transitions a piece of hardware (like a processor or
subsystem) into and out of low power modes via a direct connection to
the PMIC. It can also be wired up to interact with other processors in the
system, notifying them when a low power state is entered or exited.

+Multiple revisions of the SAW hardware are supported using these Device Nodes.
+SAW2 revisions differ in the register offset and configuration data. Also, the
+same revision of the SAW in different SoCs may have different configuration
+data due the the differences in hardware capabilities. Hence the SoC name, the
+version of the SAW hardware in that SoC and the distinction between cpu (big
+or Little) or cache, may be needed to uniquely identify the SAW register
+configuration and initialization data. The compatible string is used to
+indicate this parameter.
+
PROPERTIES

- compatible:
@@ -14,10 +23,13 @@ PROPERTIES
Value type: <string>
Definition: shall contain "qcom,saw2". A more specific value should be
one of:
- "qcom,saw2-v1"
- "qcom,saw2-v1.1"
- "qcom,saw2-v2"
- "qcom,saw2-v2.1"
+ "qcom,saw2-v1"
+ "qcom,saw2-v1.1"
+ "qcom,saw2-v2"
+ "qcom,saw2-v2.1"
+ "qcom,apq8064-saw2-v1.1-cpu"
+ "qcom,msm8974-saw2-v2.1-cpu"
+ "qcom,apq8084-saw2-v2.1-cpu"

- reg:
Usage: required
@@ -26,10 +38,17 @@ PROPERTIES
the register region. An optional second element specifies
the base address and size of the alias register region.

+- regulator:
+ Usage: optional
+ Value type: boolean
+ Definition: Indicates that this SPM device acts as a regulator device
+ device for the core (CPU or Cache) the SPM is attached
+ to.

Example:

- regulator at 2099000 {
+ power-controller at 2099000 {
compatible = "qcom,saw2";
reg = <0x02099000 0x1000>, <0x02009000 0x1000>;
+ regulator;
};
diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
index 7dcd554..012fb37 100644
--- a/drivers/soc/qcom/Kconfig
+++ b/drivers/soc/qcom/Kconfig
@@ -11,3 +11,11 @@ config QCOM_GSBI

config QCOM_SCM
bool
+
+config QCOM_PM
+ bool "Qualcomm Power Management"
+ depends on ARCH_QCOM
+ help
+ QCOM Platform specific power driver to manage cores and L2 low power
+ modes. It interface with various system drivers to put the cores in
+ low power modes.
diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index 70d52ed..20b329f 100644
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -1,3 +1,4 @@
obj-$(CONFIG_QCOM_GSBI) += qcom_gsbi.o
+obj-$(CONFIG_QCOM_PM) += spm.o
CFLAGS_scm.o :=$(call as-instr,.arch_extension sec,-DREQUIRES_SEC=1)
obj-$(CONFIG_QCOM_SCM) += scm.o scm-boot.o
diff --git a/drivers/soc/qcom/spm.c b/drivers/soc/qcom/spm.c
new file mode 100644
index 0000000..90812c5
--- /dev/null
+++ b/drivers/soc/qcom/spm.c
@@ -0,0 +1,338 @@
+/*
+ * Copyright (c) 2011-2014, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/cpuidle.h>
+#include <linux/cpu_pm.h>
+
+#include <asm/proc-fns.h>
+#include <asm/suspend.h>
+
+#include <soc/qcom/pm.h>
+#include <soc/qcom/pm.h>
+#include <soc/qcom/scm.h>
+#include <soc/qcom/scm-boot.h>
+
+
+#define SCM_CMD_TERMINATE_PC 0x2
+#define SCM_FLUSH_FLAG_MASK 0x3
+#define SCM_L2_ON 0x0
+#define SCM_L2_OFF 0x1
+#define MAX_PMIC_DATA 2
+#define MAX_SEQ_DATA 64
+#define SPM_CTL_INDEX 0x7f
+#define SPM_CTL_INDEX_SHIFT 4
+#define SPM_CTL_EN BIT(0)
+
+enum spm_reg {
+ SPM_REG_CFG,
+ SPM_REG_SPM_CTL,
+ SPM_REG_DLY,
+ SPM_REG_PMIC_DLY,
+ SPM_REG_PMIC_DATA_0,
+ SPM_REG_PMIC_DATA_1,
+ SPM_REG_VCTL,
+ SPM_REG_SEQ_ENTRY,
+ SPM_REG_SPM_STS,
+ SPM_REG_PMIC_STS,
+ SPM_REG_NR,
+};
+
+struct spm_reg_data {
+ const u8 *reg_offset;
+ u32 spm_cfg;
+ u32 spm_dly;
+ u32 pmic_dly;
+ u32 pmic_data[MAX_PMIC_DATA];
+ u8 seq[MAX_SEQ_DATA];
+ u8 start_index[PM_SLEEP_MODE_NR];
+};
+
+struct spm_driver_data {
+ void __iomem *reg_base;
+ const struct spm_reg_data *reg_data;
+};
+
+static const u8 spm_reg_offset_v2_1[SPM_REG_NR] = {
+ [SPM_REG_CFG] = 0x08,
+ [SPM_REG_SPM_CTL] = 0x30,
+ [SPM_REG_DLY] = 0x34,
+ [SPM_REG_SEQ_ENTRY] = 0x80,
+};
+
+/* SPM register data for 8974, 8084 */
+static const struct spm_reg_data spm_reg_8974_8084_cpu = {
+ .reg_offset = spm_reg_offset_v2_1,
+ .spm_cfg = 0x1,
+ .spm_dly = 0x3C102800,
+ .seq = { 0x03, 0x0B, 0x0F, 0x00, 0x20, 0x80, 0x10, 0xE8, 0x5B, 0x03,
+ 0x3B, 0xE8, 0x5B, 0x82, 0x10, 0x0B, 0x30, 0x06, 0x26, 0x30,
+ 0x0F },
+ .start_index[PM_SLEEP_MODE_STBY] = 0,
+ .start_index[PM_SLEEP_MODE_SPC] = 3,
+};
+
+static const u8 spm_reg_offset_v1_1[SPM_REG_NR] = {
+ [SPM_REG_CFG] = 0x08,
+ [SPM_REG_SPM_CTL] = 0x20,
+ [SPM_REG_PMIC_DLY] = 0x24,
+ [SPM_REG_PMIC_DATA_0] = 0x28,
+ [SPM_REG_PMIC_DATA_1] = 0x2C,
+ [SPM_REG_SEQ_ENTRY] = 0x80,
+};
+
+/* SPM register data for 8064 */
+static const struct spm_reg_data spm_reg_8064_cpu = {
+ .reg_offset = spm_reg_offset_v1_1,
+ .spm_cfg = 0x1F,
+ .pmic_dly = 0x02020004,
+ .pmic_data[0] = 0x0084009C,
+ .pmic_data[1] = 0x00A4001C,
+ .seq = { 0x03, 0x0F, 0x00, 0x24, 0x54, 0x10, 0x09, 0x03, 0x01,
+ 0x10, 0x54, 0x30, 0x0C, 0x24, 0x30, 0x0F },
+ .start_index[PM_SLEEP_MODE_STBY] = 0,
+ .start_index[PM_SLEEP_MODE_SPC] = 2,
+};
+
+static DEFINE_PER_CPU_SHARED_ALIGNED(struct spm_driver_data *, cpu_spm_drv);
+
+static inline void spm_register_write(struct spm_driver_data *drv,
+ enum spm_reg reg, u32 val)
+{
+ if (drv->reg_data->reg_offset[reg])
+ writel_relaxed(val, drv->reg_base +
+ drv->reg_data->reg_offset[reg]);
+}
+
+/* Ensure a guaranteed write, before return */
+static inline void spm_register_write_sync(struct spm_driver_data *drv,
+ enum spm_reg reg, u32 val)
+{
+ u32 ret;
+
+ if (!drv->reg_data->reg_offset[reg])
+ return;
+
+ do {
+ writel_relaxed(val, drv->reg_base +
+ drv->reg_data->reg_offset[reg]);
+ ret = readl_relaxed(drv->reg_base +
+ drv->reg_data->reg_offset[reg]);
+ if (ret == val)
+ break;
+ cpu_relax();
+ } while (1);
+}
+
+static inline u32 spm_register_read(struct spm_driver_data *drv,
+ enum spm_reg reg)
+{
+ return readl_relaxed(drv->reg_base + drv->reg_data->reg_offset[reg]);
+}
+
+static void spm_set_low_power_mode(enum pm_sleep_mode mode)
+{
+ struct spm_driver_data *drv = per_cpu(cpu_spm_drv,
+ smp_processor_id());
+ u32 start_index;
+ u32 ctl_val;
+
+ start_index = drv->reg_data->start_index[mode];
+
+ ctl_val = spm_register_read(drv, SPM_REG_SPM_CTL);
+ ctl_val &= ~(SPM_CTL_INDEX << SPM_CTL_INDEX_SHIFT);
+ ctl_val |= start_index << SPM_CTL_INDEX_SHIFT;
+ ctl_val |= SPM_CTL_EN;
+ spm_register_write_sync(drv, SPM_REG_SPM_CTL, ctl_val);
+}
+
+static int qcom_pm_collapse(unsigned long int unused)
+{
+ int ret;
+ u32 flag;
+ int cpu = smp_processor_id();
+
+ ret = scm_set_warm_boot_addr(cpu_resume, cpu);
+ if (ret)
+ return ret;
+
+ flag = SCM_L2_ON & SCM_FLUSH_FLAG_MASK;
+ ret = scm_call_atomic1(SCM_SVC_BOOT, SCM_CMD_TERMINATE_PC, flag);
+
+ /*
+ * Returns here only if there was a pending interrupt and we did not
+ * power down as a result.
+ */
+ return ret;
+}
+
+static int qcom_cpu_standby(void *unused)
+{
+ spm_set_low_power_mode(PM_SLEEP_MODE_STBY);
+ cpu_do_idle();
+
+ return 0;
+}
+
+static int qcom_cpu_spc(void *unused)
+{
+ int ret;
+
+ spm_set_low_power_mode(PM_SLEEP_MODE_STBY);
+ cpu_pm_enter();
+ ret = cpu_suspend(0, qcom_pm_collapse);
+ cpu_pm_exit();
+
+ return ret;
+}
+
+static struct spm_driver_data *spm_get_drv(struct platform_device *pdev,
+ int *spm_cpu)
+{
+ struct spm_driver_data *drv = NULL;
+ struct device_node *cpu_node, *saw_node;
+ int cpu;
+ bool found;
+
+ for_each_possible_cpu(cpu) {
+ cpu_node = of_cpu_device_node_get(cpu);
+ if (!cpu_node)
+ continue;
+ saw_node = of_parse_phandle(cpu_node, "qcom,saw", 0);
+ found = (saw_node == pdev->dev.of_node);
+ of_node_put(saw_node);
+ of_node_put(cpu_node);
+ if (found)
+ break;
+ }
+
+ if (found) {
+ drv = devm_kzalloc(&pdev->dev, sizeof(*drv), GFP_KERNEL);
+ if (drv)
+ *spm_cpu = cpu;
+ }
+
+ return drv;
+}
+
+static const struct of_device_id spm_match_table[] = {
+ { .compatible = "qcom,msm8974-saw2-v2.1-cpu",
+ .data = &spm_reg_8974_8084_cpu },
+ { .compatible = "qcom,apq8084-saw2-v2.1-cpu",
+ .data = &spm_reg_8974_8084_cpu },
+ { .compatible = "qcom,apq8064-saw2-v1.1-cpu",
+ .data = &spm_reg_8064_cpu },
+ { },
+};
+
+static int spm_dev_probe(struct platform_device *pdev)
+{
+ struct spm_driver_data *drv;
+ struct resource *res;
+ const struct of_device_id *match_id;
+ void __iomem *addr;
+ int cpu;
+ struct cpuidle_device *dev;
+
+ drv = spm_get_drv(pdev, &cpu);
+ if (!drv)
+ return -EINVAL;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ drv->reg_base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(drv->reg_base))
+ return PTR_ERR(drv->reg_base);
+
+ match_id = of_match_node(spm_match_table, pdev->dev.of_node);
+ if (!match_id)
+ return -ENODEV;
+
+ drv->reg_data = match_id->data;
+
+ /* Write the SPM sequences first.. */
+ addr = drv->reg_base + drv->reg_data->reg_offset[SPM_REG_SEQ_ENTRY];
+ __iowrite32_copy(addr, drv->reg_data->seq,
+ ARRAY_SIZE(drv->reg_data->seq) / 4);
+
+ /*
+ * ..and then the control registers.
+ * On some SoC if the control registers are written first and if the
+ * CPU was held in reset, the reset signal could trigger the SPM state
+ * machine, before the sequences are completely written.
+ */
+ spm_register_write(drv, SPM_REG_CFG, drv->reg_data->spm_cfg);
+ spm_register_write(drv, SPM_REG_DLY, drv->reg_data->spm_dly);
+ spm_register_write(drv, SPM_REG_PMIC_DLY, drv->reg_data->pmic_dly);
+ spm_register_write(drv, SPM_REG_PMIC_DATA_0,
+ drv->reg_data->pmic_data[0]);
+ spm_register_write(drv, SPM_REG_PMIC_DATA_1,
+ drv->reg_data->pmic_data[1]);
+
+ per_cpu(cpu_spm_drv, cpu) = drv;
+
+ /* Register the cpuidle device for the cpu, we are ready for cpuidle */
+ dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
+ if (!dev)
+ return -ENOMEM;
+
+ dev->cpu = cpu;
+ return cpuidle_register_device(dev);
+}
+
+static struct qcom_cpu_pm_ops lpm_ops = {
+ .standby = qcom_cpu_standby,
+ .spc = qcom_cpu_spc,
+};
+
+static struct platform_device qcom_cpuidle_drv = {
+ .name = "qcom_cpuidle",
+ .id = -1,
+ .dev.platform_data = &lpm_ops,
+};
+
+static struct platform_driver spm_driver = {
+ .probe = spm_dev_probe,
+ .driver = {
+ .name = "saw",
+ .of_match_table = spm_match_table,
+ },
+};
+
+static int __init qcom_spm_init(void)
+{
+ int ret;
+
+ /*
+ * cpuidle driver need to registered before the cpuidle device
+ * for any cpu. Register the device for the the cpuidle driver.
+ */
+ ret = platform_device_register(&qcom_cpuidle_drv);
+ if (ret)
+ return ret;
+
+ return platform_driver_register(&spm_driver);
+}
+module_init(qcom_spm_init);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("SAW power controller driver");
+MODULE_ALIAS("platform:saw");
diff --git a/include/soc/qcom/pm.h b/include/soc/qcom/pm.h
new file mode 100644
index 0000000..d9a56d7
--- /dev/null
+++ b/include/soc/qcom/pm.h
@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2009-2014, The Linux Foundation. All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef __QCOM_PM_H
+#define __QCOM_PM_H
+
+enum pm_sleep_mode {
+ PM_SLEEP_MODE_STBY,
+ PM_SLEEP_MODE_RET,
+ PM_SLEEP_MODE_SPC,
+ PM_SLEEP_MODE_PC,
+ PM_SLEEP_MODE_NR,
+};
+
+struct qcom_cpu_pm_ops {
+ int (*standby)(void *data);
+ int (*spc)(void *data);
+};
+
+#endif /* __QCOM_PM_H */
--
2.1.0