soc: qcom: rpmpd: Add a Power domain driver to model corners

The Power domains for corners just pass the performance state set by the
consumers to the RPM (Remote Power manager) which then takes care
of setting the appropriate voltage on the corresponding rails to
meet the performance needs.

We add all power domain data needed on msm8996 here. This driver can easily
be extended by adding data for other qualcomm SoCs as well.

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>

drivers/soc/qcom/Kconfig

@@ -98,6 +98,15 @@ config QCOM_RPMH
 	  of hardware components aggregate requests for these resources and
 	  help apply the aggregated state on the resource.
 
+config QCOM_RPMPD
+	bool "Qualcomm RPM Power domain driver"
+	depends on MFD_QCOM_RPM && QCOM_SMD_RPM
+	help
+	  QCOM RPM Power domain driver to support power-domains with
+	  performance states. The driver communicates a performance state
+	  value to RPM which then translates it into corresponding voltage
+	  for the voltage rail.
+
 config QCOM_SMEM
 	tristate "Qualcomm Shared Memory Manager (SMEM)"
 	depends on ARCH_QCOM || COMPILE_TEST

drivers/soc/qcom/Makefile

@@ -21,3 +21,4 @@ obj-$(CONFIG_QCOM_WCNSS_CTRL) += wcnss_ctrl.o
 obj-$(CONFIG_QCOM_APR) += apr.o
 obj-$(CONFIG_QCOM_LLCC) += llcc-slice.o
 obj-$(CONFIG_QCOM_SDM845_LLCC) += llcc-sdm845.o
+obj-$(CONFIG_QCOM_RPMPD) += rpmpd.o

drivers/soc/qcom/rpmpd.c

@@ -0,0 +1,282 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2017-2018, The Linux Foundation. All rights reserved. */
+
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mutex.h>
+#include <linux/pm_domain.h>
+#include <linux/mfd/qcom_rpm.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/soc/qcom/smd-rpm.h>
+
+#include <dt-bindings/mfd/qcom-rpm.h>
+#include <dt-bindings/power/qcom-rpmpd.h>
+
+#define domain_to_rpmpd(domain) container_of(domain, struct rpmpd, pd)
+
+/* Resource types */
+#define RPMPD_SMPA 0x61706d73
+#define RPMPD_LDOA 0x616f646c
+
+/* Operation Keys */
+#define KEY_CORNER		0x6e726f63 /* corn */
+#define KEY_ENABLE		0x6e657773 /* swen */
+#define KEY_FLOOR_CORNER	0x636676   /* vfc */
+
+#define DEFINE_RPMPD_CORNER_SMPA(_platform, _name, _active, r_id)		\
+	static struct rpmpd _platform##_##_active;			\
+	static struct rpmpd _platform##_##_name = {			\
+		.pd = {	.name = #_name,	},				\
+		.peer = &_platform##_##_active,				\
+		.res_type = RPMPD_SMPA,					\
+		.res_id = r_id,						\
+		.key = KEY_CORNER,					\
+	};								\
+	static struct rpmpd _platform##_##_active = {			\
+		.pd = { .name = #_active, },				\
+		.peer = &_platform##_##_name,				\
+		.active_only = true,					\
+		.res_type = RPMPD_SMPA,					\
+		.res_id = r_id,						\
+		.key = KEY_CORNER,					\
+	}
+
+#define DEFINE_RPMPD_CORNER_LDOA(_platform, _name, r_id)			\
+	static struct rpmpd _platform##_##_name = {			\
+		.pd = { .name = #_name, },				\
+		.res_type = RPMPD_LDOA,					\
+		.res_id = r_id,						\
+		.key = KEY_CORNER,					\
+	}
+
+#define DEFINE_RPMPD_VFC(_platform, _name, r_id, r_type)		\
+	static struct rpmpd _platform##_##_name = {			\
+		.pd = { .name = #_name, },				\
+		.res_type = r_type,					\
+		.res_id = r_id,						\
+		.key = KEY_FLOOR_CORNER,				\
+	}
+
+#define DEFINE_RPMPD_VFC_SMPA(_platform, _name, r_id)			\
+	DEFINE_RPMPD_VFC(_platform, _name, r_id, RPMPD_SMPA)
+
+#define DEFINE_RPMPD_VFC_LDOA(_platform, _name, r_id)			\
+	DEFINE_RPMPD_VFC(_platform, _name, r_id, RPMPD_LDOA)
+
+struct rpmpd_req {
+	__le32 key;
+	__le32 nbytes;
+	__le32 value;
+};
+
+struct rpmpd {
+	struct generic_pm_domain pd;
+	struct rpmpd *peer;
+	const bool active_only;
+	unsigned int corner;
+	bool enabled;
+	const char *res_name;
+	const int res_type;
+	const int res_id;
+	struct qcom_smd_rpm *rpm;
+	__le32 key;
+};
+
+struct rpmpd_desc {
+	struct rpmpd **rpmpds;
+	size_t num_pds;
+};
+
+static DEFINE_MUTEX(rpmpd_lock);
+
+/* msm8996 RPM Power domains */
+DEFINE_RPMPD_CORNER_SMPA(msm8996, vddcx, vddcx_ao, 1);
+DEFINE_RPMPD_CORNER_SMPA(msm8996, vddmx, vddmx_ao, 2);
+DEFINE_RPMPD_CORNER_LDOA(msm8996, vddsscx, 26);
+
+DEFINE_RPMPD_VFC_SMPA(msm8996, vddcx_vfc, 1);
+DEFINE_RPMPD_VFC_LDOA(msm8996, vddsscx_vfc, 26);
+
+static struct rpmpd *msm8996_rpmpds[] = {
+	[MSM8996_VDDCX] =	&msm8996_vddcx,
+	[MSM8996_VDDCX_AO] =	&msm8996_vddcx_ao,
+	[MSM8996_VDDCX_VFC] =	&msm8996_vddcx_vfc,
+	[MSM8996_VDDMX] =	&msm8996_vddmx,
+	[MSM8996_VDDMX_AO] =	&msm8996_vddmx_ao,
+	[MSM8996_VDDSSCX] =	&msm8996_vddsscx,
+	[MSM8996_VDDSSCX_VFC] =	&msm8996_vddsscx_vfc,
+};
+
+static const struct rpmpd_desc msm8996_desc = {
+	.rpmpds = msm8996_rpmpds,
+	.num_pds = ARRAY_SIZE(msm8996_rpmpds),
+};
+
+static const struct of_device_id rpmpd_match_table[] = {
+	{ .compatible = "qcom,msm8996-rpmpd", .data = &msm8996_desc },
+	{ }
+};
+
+static int rpmpd_send_enable(struct rpmpd *pd, bool enable)
+{
+	struct rpmpd_req req = {
+		.key = KEY_ENABLE,
+		.nbytes = cpu_to_le32(sizeof(u32)),
+		.value = cpu_to_le32(enable),
+	};
+
+	return qcom_rpm_smd_write(pd->rpm, QCOM_RPM_ACTIVE_STATE, pd->res_type,
+				  pd->res_id, &req, sizeof(req));
+}
+
+static int rpmpd_send_corner(struct rpmpd *pd, int state, unsigned int corner)
+{
+	struct rpmpd_req req = {
+		.key = pd->key,
+		.nbytes = cpu_to_le32(sizeof(u32)),
+		.value = cpu_to_le32(corner),
+	};
+
+	return qcom_rpm_smd_write(pd->rpm, state, pd->res_type, pd->res_id,
+				  &req, sizeof(req));
+};
+
+static void to_active_sleep(struct rpmpd *pd, unsigned int corner,
+			    unsigned int *active, unsigned int *sleep)
+{
+	*active = corner;
+
+	if (pd->active_only)
+		*sleep = 0;
+	else
+		*sleep = *active;
+}
+
+static int rpmpd_aggregate_corner(struct rpmpd *pd)
+{
+	int ret;
+	struct rpmpd *peer = pd->peer;
+	unsigned int active_corner, sleep_corner;
+	unsigned int this_active_corner = 0, this_sleep_corner = 0;
+	unsigned int peer_active_corner = 0, peer_sleep_corner = 0;
+
+	to_active_sleep(pd, pd->corner, &this_active_corner, &this_sleep_corner);
+
+	if (peer && peer->enabled)
+		to_active_sleep(peer, peer->corner, &peer_active_corner,
+				&peer_sleep_corner);
+
+	active_corner = max(this_active_corner, peer_active_corner);
+
+	ret = rpmpd_send_corner(pd, QCOM_RPM_ACTIVE_STATE, active_corner);
+	if (ret)
+		return ret;
+
+	sleep_corner = max(this_sleep_corner, peer_sleep_corner);
+
+	return rpmpd_send_corner(pd, QCOM_RPM_SLEEP_STATE, sleep_corner);
+}
+
+static int rpmpd_power_on(struct generic_pm_domain *domain)
+{
+	int ret;
+	struct rpmpd *pd = domain_to_rpmpd(domain);
+
+	mutex_lock(&rpmpd_lock);
+
+	ret = rpmpd_send_enable(pd, true);
+	if (ret)
+		goto out;
+
+	pd->enabled = true;
+
+	if (pd->corner)
+		ret = rpmpd_aggregate_corner(pd);
+
+out:
+	mutex_unlock(&rpmpd_lock);
+
+	return ret;
+}
+
+static int rpmpd_power_off(struct generic_pm_domain *domain)
+{
+	int ret;
+	struct rpmpd *pd = domain_to_rpmpd(domain);
+
+	mutex_lock(&rpmpd_lock);
+
+	ret = rpmpd_send_enable(pd, false);
+	if (!ret)
+		pd->enabled = false;
+
+	mutex_unlock(&rpmpd_lock);
+
+	return ret;
+}
+
+static int rpmpd_probe(struct platform_device *pdev)
+{
+	int i;
+	size_t num;
+	struct genpd_onecell_data *data;
+	struct qcom_smd_rpm *rpm;
+	struct rpmpd **rpmpds;
+	const struct rpmpd_desc *desc;
+
+	rpm = dev_get_drvdata(pdev->dev.parent);
+	if (!rpm) {
+		dev_err(&pdev->dev, "Unable to retrieve handle to RPM\n");
+		return -ENODEV;
+	}
+
+	desc = of_device_get_match_data(&pdev->dev);
+	if (!desc)
+		return -EINVAL;
+
+	rpmpds = desc->rpmpds;
+	num = desc->num_pds;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->domains = devm_kcalloc(&pdev->dev, num, sizeof(*data->domains),
+				     GFP_KERNEL);
+	data->num_domains = num;
+
+	for (i = 0; i < num; i++) {
+		if (!rpmpds[i]) {
+			dev_warn(&pdev->dev, "rpmpds[] with empty entry at index=%d\n",
+				 i);
+			continue;
+		}
+
+		rpmpds[i]->rpm = rpm;
+		rpmpds[i]->pd.power_off = rpmpd_power_off;
+		rpmpds[i]->pd.power_on = rpmpd_power_on;
+		pm_genpd_init(&rpmpds[i]->pd, NULL, true);
+
+		data->domains[i] = &rpmpds[i]->pd;
+	}
+
+	return of_genpd_add_provider_onecell(pdev->dev.of_node, data);
+}
+
+static struct platform_driver rpmpd_driver = {
+	.driver = {
+		.name = "qcom-rpmpd",
+		.of_match_table = rpmpd_match_table,
+		.suppress_bind_attrs = true,
+	},
+	.probe = rpmpd_probe,
+};
+
+static int __init rpmpd_init(void)
+{
+	return platform_driver_register(&rpmpd_driver);
+}
+core_initcall(rpmpd_init);