[PATCH v3 08/28] soc: qcom: spm: add support for voltage regulator

Dmitry Baryshkov
2023-07-02T17:43:25Z

The SPM / SAW2 device also provides a voltage regulator functionality
with optional AVS (Adaptive Voltage Scaling) support. The exact register
sequence and voltage ranges differs from device to device.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
drivers/soc/qcom/spm.c | 205 ++++++++++++++++++++++++++++++++++++++++-
include/soc/qcom/spm.h | 9 ++
2 files changed, 212 insertions(+), 2 deletions(-)

diff --git a/drivers/soc/qcom/spm.c b/drivers/soc/qcom/spm.c
index a6cbeb40831b..3c16a7e1710c 100644
--- a/drivers/soc/qcom/spm.c
+++ b/drivers/soc/qcom/spm.c
@@ -9,19 +9,31 @@
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/linear_range.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
+#include <linux/bitfield.h>
#include <linux/err.h>
#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/smp.h>
#include <soc/qcom/spm.h>

+#define FIELD_SET(current, mask, val) \
+ (((current) & ~(mask)) | FIELD_PREP((mask), (val)))
+
#define SPM_CTL_INDEX 0x7f
#define SPM_CTL_INDEX_SHIFT 4
#define SPM_CTL_EN BIT(0)

+#define SPM_1_1_AVS_CTL_AVS_ENABLED BIT(27)
+#define SPM_AVS_CTL_MIN_VLVL (0x3f << 10)
+#define SPM_AVS_CTL_MAX_VLVL (0x3f << 17)
+
enum spm_reg {
SPM_REG_CFG,
SPM_REG_SPM_CTL,
@@ -31,10 +43,12 @@ enum spm_reg {
SPM_REG_PMIC_DATA_1,
SPM_REG_VCTL,
SPM_REG_SEQ_ENTRY,
- SPM_REG_SPM_STS,
+ SPM_REG_STS0,
+ SPM_REG_STS1,
SPM_REG_PMIC_STS,
SPM_REG_AVS_CTL,
SPM_REG_AVS_LIMIT,
+ SPM_REG_RST,
SPM_REG_NR,
};

@@ -171,6 +185,10 @@ static const struct spm_reg_data spm_reg_8226_cpu = {

static const u16 spm_reg_offset_v1_1[SPM_REG_NR] = {
[SPM_REG_CFG] = 0x08,
+ [SPM_REG_STS0] = 0x0c,
+ [SPM_REG_STS1] = 0x10,
+ [SPM_REG_VCTL] = 0x14,
+ [SPM_REG_AVS_CTL] = 0x18,
[SPM_REG_SPM_CTL] = 0x20,
[SPM_REG_PMIC_DLY] = 0x24,
[SPM_REG_PMIC_DATA_0] = 0x28,
@@ -178,7 +196,12 @@ static const u16 spm_reg_offset_v1_1[SPM_REG_NR] = {
[SPM_REG_SEQ_ENTRY] = 0x80,
};

+static void smp_set_vdd_v1_1(void *data);
+
/* SPM register data for 8064 */
+static struct linear_range spm_v1_1_regulator_range =
+ REGULATOR_LINEAR_RANGE(700000, 0, 56, 12500);
+
static const struct spm_reg_data spm_reg_8064_cpu = {
.reg_offset = spm_reg_offset_v1_1,
.spm_cfg = 0x1F,
@@ -189,6 +212,10 @@ static const struct spm_reg_data spm_reg_8064_cpu = {
0x10, 0x54, 0x30, 0x0C, 0x24, 0x30, 0x0F },
.start_index[PM_SLEEP_MODE_STBY] = 0,
.start_index[PM_SLEEP_MODE_SPC] = 2,
+ .set_vdd = smp_set_vdd_v1_1,
+ .range = &spm_v1_1_regulator_range,
+ .init_uV = 1300000,
+ .ramp_delay = 1250,
};

static inline void spm_register_write(struct spm_driver_data *drv,
@@ -240,6 +267,179 @@ void spm_set_low_power_mode(struct spm_driver_data *drv,
spm_register_write_sync(drv, SPM_REG_SPM_CTL, ctl_val);
}

+static int spm_set_voltage_sel(struct regulator_dev *rdev, unsigned int selector)
+{
+ struct spm_driver_data *drv = rdev_get_drvdata(rdev);
+
+ drv->volt_sel = selector;
+
+ /* Always do the SAW register writes on the corresponding CPU */
+ return smp_call_function_single(drv->reg_cpu, drv->reg_data->set_vdd, drv, true);
+}
+
+static int spm_get_voltage_sel(struct regulator_dev *rdev)
+{
+ struct spm_driver_data *drv = rdev_get_drvdata(rdev);
+
+ return drv->volt_sel;
+}
+
+static const struct regulator_ops spm_reg_ops = {
+ .set_voltage_sel = spm_set_voltage_sel,
+ .get_voltage_sel = spm_get_voltage_sel,
+ .list_voltage = regulator_list_voltage_linear_range,
+ .set_voltage_time_sel = regulator_set_voltage_time_sel,
+};
+
+static void smp_set_vdd_v1_1(void *data)
+{
+ struct spm_driver_data *drv = data;
+ unsigned int vlevel = drv->volt_sel;
+ unsigned int vctl, data0, data1, avs_ctl, sts;
+ bool avs_enabled;
+
+ vlevel |= 0x80; /* band */
+
+ avs_ctl = spm_register_read(drv, SPM_REG_AVS_CTL);
+ vctl = spm_register_read(drv, SPM_REG_VCTL);
+ data0 = spm_register_read(drv, SPM_REG_PMIC_DATA_0);
+ data1 = spm_register_read(drv, SPM_REG_PMIC_DATA_1);
+
+ avs_enabled = avs_ctl & SPM_1_1_AVS_CTL_AVS_ENABLED;
+
+ /* If AVS is enabled, switch it off during the voltage change */
+ if (avs_enabled) {
+ avs_ctl &= ~SPM_1_1_AVS_CTL_AVS_ENABLED;
+ spm_register_write(drv, SPM_REG_AVS_CTL, avs_ctl);
+ }
+
+ /* Kick the state machine back to idle */
+ spm_register_write(drv, SPM_REG_RST, 1);
+
+ vctl = FIELD_SET(vctl, 0xff, vlevel);
+ data0 = FIELD_SET(data0, 0xff, vlevel);
+ data1 = FIELD_SET(data1, 0x3f, vlevel);
+ data1 = FIELD_SET(data1, 0x3f << 16, vlevel);
+
+ spm_register_write(drv, SPM_REG_VCTL, vctl);
+ spm_register_write(drv, SPM_REG_PMIC_DATA_0, data0);
+ spm_register_write(drv, SPM_REG_PMIC_DATA_1, data1);
+
+ if (read_poll_timeout_atomic(spm_register_read,
+ sts, sts == vlevel,
+ 1, 200, false,
+ drv, SPM_REG_STS1)) {
+ dev_err_ratelimited(drv->dev, "timeout setting the voltage (%x %x)!\n", sts, vlevel);
+ goto enable_avs;
+ }
+
+ if (avs_enabled) {
+ unsigned int max_avs = vlevel & 0x3f;
+ unsigned int min_avs = max(max_avs, 4U) - 4;
+ avs_ctl = FIELD_SET(avs_ctl, SPM_AVS_CTL_MIN_VLVL, min_avs);
+ avs_ctl = FIELD_SET(avs_ctl, SPM_AVS_CTL_MAX_VLVL, max_avs);
+ spm_register_write(drv, SPM_REG_AVS_CTL, avs_ctl);
+ }
+
+enable_avs:
+ if (avs_enabled) {
+ avs_ctl |= SPM_1_1_AVS_CTL_AVS_ENABLED;
+ spm_register_write(drv, SPM_REG_AVS_CTL, avs_ctl);
+ }
+}
+
+static int spm_get_cpu(struct device *dev)
+{
+ int cpu;
+ bool found;
+
+ for_each_possible_cpu(cpu) {
+ struct device_node *cpu_node, *saw_node;
+
+ 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 == dev->of_node);
+ of_node_put(saw_node);
+ of_node_put(cpu_node);
+
+ if (found)
+ return cpu;
+ }
+
+ /* L2 SPM is not bound to any CPU, tie it to CPU0 */
+
+ return 0;
+}
+
+#ifdef CONFIG_REGULATOR
+static int spm_register_regulator(struct device *dev, struct spm_driver_data *drv)
+{
+ struct regulator_config config = {
+ .dev = dev,
+ .driver_data = drv,
+ };
+ struct regulator_desc *rdesc;
+ struct regulator_dev *rdev;
+ int ret;
+ bool found;
+
+ if (!drv->reg_data->set_vdd)
+ return 0;
+
+ rdesc = devm_kzalloc(dev, sizeof(*rdesc), GFP_KERNEL);
+ if (!rdesc)
+ return -ENOMEM;
+
+ rdesc->name = "spm";
+ rdesc->of_match = of_match_ptr("regulator");
+ rdesc->type = REGULATOR_VOLTAGE;
+ rdesc->owner = THIS_MODULE;
+ rdesc->ops = &spm_reg_ops;
+
+ rdesc->linear_ranges = drv->reg_data->range;
+ rdesc->n_linear_ranges = 1;
+ rdesc->n_voltages = rdesc->linear_ranges[rdesc->n_linear_ranges - 1].max_sel + 1;
+ rdesc->ramp_delay = drv->reg_data->ramp_delay;
+
+ drv->reg_cpu = spm_get_cpu(dev);
+ dev_dbg(dev, "SAW2 bound to CPU %d\n", drv->reg_cpu);
+
+ /*
+ * Program initial voltage, otherwise registration will also try
+ * setting the voltage, which might result in undervolting the CPU.
+ */
+ drv->volt_sel = DIV_ROUND_UP(drv->reg_data->init_uV - rdesc->min_uV,
+ rdesc->uV_step);
+ ret = linear_range_get_selector_high(drv->reg_data->range,
+ drv->reg_data->init_uV,
+ &drv->volt_sel,
+ &found);
+ if (ret) {
+ dev_err(dev, "Initial uV value out of bounds\n");
+ return ret;
+ }
+
+ /* Always do the SAW register writes on the corresponding CPU */
+ smp_call_function_single(drv->reg_cpu, drv->reg_data->set_vdd, drv, true);
+
+ rdev = devm_regulator_register(dev, rdesc, &config);
+ if (IS_ERR(rdev)) {
+ dev_err(dev, "failed to register regulator\n");
+ return PTR_ERR(rdev);
+ }
+
+ return 0;
+}
+#else
+static int spm_register_regulator(struct device *dev, struct spm_driver_data *drv)
+{
+ return 0;
+}
+#endif
+
static const struct of_device_id spm_match_table[] = {
{ .compatible = "qcom,sdm660-gold-saw2-v4.1-l2",
.data = &spm_reg_660_gold_l2 },
@@ -292,6 +492,7 @@ static int spm_dev_probe(struct platform_device *pdev)
return -ENODEV;

drv->reg_data = match_id->data;
+ drv->dev = &pdev->dev;
platform_set_drvdata(pdev, drv);

/* Write the SPM sequences first.. */
@@ -319,7 +520,7 @@ static int spm_dev_probe(struct platform_device *pdev)
if (drv->reg_data->reg_offset[SPM_REG_SPM_CTL])
spm_set_low_power_mode(drv, PM_SLEEP_MODE_STBY);

- return 0;
+ return spm_register_regulator(&pdev->dev, drv);
}

static struct platform_driver spm_driver = {
diff --git a/include/soc/qcom/spm.h b/include/soc/qcom/spm.h
index 4951f9d8b0bd..9859ebe42003 100644
--- a/include/soc/qcom/spm.h
+++ b/include/soc/qcom/spm.h
@@ -30,11 +30,20 @@ struct spm_reg_data {
u32 avs_limit;
u8 seq[MAX_SEQ_DATA];
u8 start_index[PM_SLEEP_MODE_NR];
+
+ smp_call_func_t set_vdd;
+ /* for now we support only a single range */
+ struct linear_range *range;
+ unsigned int ramp_delay;
+ unsigned int init_uV;
};

struct spm_driver_data {
void __iomem *reg_base;
const struct spm_reg_data *reg_data;
+ struct device *dev;
+ unsigned int volt_sel;
+ int reg_cpu;
};

void spm_set_low_power_mode(struct spm_driver_data *drv,
--
2.39.2