[PATCH v7 2/2] clk: qcom: Add support for RPM Clocks

Georgi Djakov
2016-02-23T16:13:19Z

This adds initial support for clocks controlled by the Resource
Power Manager (RPM) processor on some Qualcomm SoCs, which use
the qcom_rpm driver to communicate with RPM.
Such platforms are apq8064 and msm8960.

Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
---
.../devicetree/bindings/clock/qcom,rpmcc.txt | 1 +
drivers/clk/qcom/Kconfig | 13 +
drivers/clk/qcom/Makefile | 1 +
drivers/clk/qcom/clk-rpm.c | 474 ++++++++++++++++++++
include/dt-bindings/clock/qcom,rpmcc.h | 24 +
5 files changed, 513 insertions(+)
create mode 100644 drivers/clk/qcom/clk-rpm.c

diff --git a/Documentation/devicetree/bindings/clock/qcom,rpmcc.txt b/Documentation/devicetree/bindings/clock/qcom,rpmcc.txt
index e3e13226d798..87d3714b956a 100644
--- a/Documentation/devicetree/bindings/clock/qcom,rpmcc.txt
+++ b/Documentation/devicetree/bindings/clock/qcom,rpmcc.txt
@@ -11,6 +11,7 @@ Required properties :
compatible "qcom,rpmcc" should be also included.

"qcom,rpmcc-msm8916", "qcom,rpmcc"
+ "qcom,rpmcc-apq8064", "qcom,rpmcc"

- #clock-cells : shall contain 1

diff --git a/drivers/clk/qcom/Kconfig b/drivers/clk/qcom/Kconfig
index 5963d36f0c45..8321e523e515 100644
--- a/drivers/clk/qcom/Kconfig
+++ b/drivers/clk/qcom/Kconfig
@@ -12,6 +12,19 @@ config COMMON_CLK_QCOM
select REGMAP_MMIO
select RESET_CONTROLLER

+config QCOM_CLK_RPM
+ tristate "RPM based Clock Controller"
+ depends on COMMON_CLK_QCOM && MFD_QCOM_RPM
+ select QCOM_RPMCC
+ help
+ The RPM (Resource Power Manager) is a dedicated hardware engine for
+ managing the shared SoC resources in order to keep the lowest power
+ profile. It communicates with other hardware subsystems via shared
+ memory and accepts clock requests, aggregates the requests and turns
+ the clocks on/off or scales them on demand.
+ Say Y if you want to support the clocks exposed by the RPM on
+ platforms such as apq8064, msm8660, msm8960 etc.
+
config QCOM_CLK_SMD_RPM
tristate "RPM over SMD based Clock Controller"
depends on COMMON_CLK_QCOM && QCOM_SMD_RPM
diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
index 5f4673b7b03a..5a1fc45b12cf 100644
--- a/drivers/clk/qcom/Makefile
+++ b/drivers/clk/qcom/Makefile
@@ -25,4 +25,5 @@ obj-$(CONFIG_MSM_GCC_8996) += gcc-msm8996.o
obj-$(CONFIG_MSM_MMCC_8960) += mmcc-msm8960.o
obj-$(CONFIG_MSM_MMCC_8974) += mmcc-msm8974.o
obj-$(CONFIG_MSM_MMCC_8996) += mmcc-msm8996.o
+obj-$(CONFIG_QCOM_CLK_RPM) += clk-rpm.o
obj-$(CONFIG_QCOM_CLK_SMD_RPM) += clk-smd-rpm.o
diff --git a/drivers/clk/qcom/clk-rpm.c b/drivers/clk/qcom/clk-rpm.c
new file mode 100644
index 000000000000..715c0a5d34ca
--- /dev/null
+++ b/drivers/clk/qcom/clk-rpm.c
@@ -0,0 +1,474 @@
+/*
+ * Copyright (c) 2016, Linaro Limited
+ * Copyright (c) 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.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/mfd/qcom_rpm.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+
+#include <dt-bindings/mfd/qcom-rpm.h>
+#include <dt-bindings/clock/qcom,rpmcc.h>
+
+#define QCOM_RPM_MISC_CLK_TYPE 0x306b6c63
+#define QCOM_RPM_SCALING_ENABLE_ID 0x2
+
+#define DEFINE_CLK_RPM(_platform, _name, _active, r_id) \
+ static struct clk_rpm _platform##_##_active; \
+ static struct clk_rpm _platform##_##_name = { \
+ .rpm_clk_id = (r_id), \
+ .peer = &_platform##_##_active, \
+ .rate = INT_MAX, \
+ .hw.init = &(struct clk_init_data){ \
+ .ops = &clk_rpm_ops, \
+ .name = #_name, \
+ .parent_names = (const char *[]){ "pxo_board" }, \
+ .num_parents = 1, \
+ }, \
+ }; \
+ static struct clk_rpm _platform##_##_active = { \
+ .rpm_clk_id = (r_id), \
+ .peer = &_platform##_##_name, \
+ .active_only = true, \
+ .rate = INT_MAX, \
+ .hw.init = &(struct clk_init_data){ \
+ .ops = &clk_rpm_ops, \
+ .name = #_active, \
+ .parent_names = (const char *[]){ "pxo_board" }, \
+ .num_parents = 1, \
+ }, \
+ }
+
+#define DEFINE_CLK_RPM_PXO_BRANCH(_platform, _name, _active, r_id, r) \
+ static struct clk_rpm _platform##_##_active; \
+ static struct clk_rpm _platform##_##_name = { \
+ .rpm_clk_id = (r_id), \
+ .active_only = true, \
+ .peer = &_platform##_##_active, \
+ .rate = (r), \
+ .branch = true, \
+ .hw.init = &(struct clk_init_data){ \
+ .ops = &clk_rpm_branch_ops, \
+ .name = #_name, \
+ .parent_names = (const char *[]){ "pxo_board" }, \
+ .num_parents = 1, \
+ }, \
+ }; \
+ static struct clk_rpm _platform##_##_active = { \
+ .rpm_clk_id = (r_id), \
+ .peer = &_platform##_##_name, \
+ .rate = (r), \
+ .branch = true, \
+ .hw.init = &(struct clk_init_data){ \
+ .ops = &clk_rpm_branch_ops, \
+ .name = #_active, \
+ .parent_names = (const char *[]){ "pxo_board" }, \
+ .num_parents = 1, \
+ }, \
+ }
+
+#define DEFINE_CLK_RPM_CXO_BRANCH(_platform, _name, _active, r_id, r) \
+ static struct clk_rpm _platform##_##_active; \
+ static struct clk_rpm _platform##_##_name = { \
+ .rpm_clk_id = (r_id), \
+ .peer = &_platform##_##_active, \
+ .rate = (r), \
+ .branch = true, \
+ .hw.init = &(struct clk_init_data){ \
+ .ops = &clk_rpm_branch_ops, \
+ .name = #_name, \
+ .parent_names = (const char *[]){ "cxo_board" }, \
+ .num_parents = 1, \
+ }, \
+ }; \
+ static struct clk_rpm _platform##_##_active = { \
+ .rpm_clk_id = (r_id), \
+ .active_only = true, \
+ .peer = &_platform##_##_name, \
+ .rate = (r), \
+ .branch = true, \
+ .hw.init = &(struct clk_init_data){ \
+ .ops = &clk_rpm_branch_ops, \
+ .name = #_active, \
+ .parent_names = (const char *[]){ "cxo_board" }, \
+ .num_parents = 1, \
+ }, \
+ }
+
+#define to_clk_rpm(_hw) container_of(_hw, struct clk_rpm, hw)
+
+struct clk_rpm {
+ const int rpm_clk_id;
+ const bool active_only;
+ unsigned long rate;
+ bool enabled;
+ bool branch;
+ struct clk_rpm *peer;
+ struct clk_hw hw;
+ struct qcom_rpm *rpm;
+};
+
+struct rpm_cc {
+ struct qcom_rpm *rpm;
+ struct clk_onecell_data data;
+ struct clk *clks[];
+};
+
+struct rpm_clk_desc {
+ struct clk_rpm **clks;
+ size_t num_clks;
+};
+
+static DEFINE_MUTEX(rpm_clk_lock);
+
+static int clk_rpm_set_rate_active(struct clk_rpm *r, unsigned long rate)
+{
+ u32 value = DIV_ROUND_UP(rate, 1000); /* to kHz */
+
+ return qcom_rpm_write(r->rpm, QCOM_RPM_ACTIVE_STATE,
+ r->rpm_clk_id, &value, 1);
+}
+
+static int clk_rpm_set_rate_sleep(struct clk_rpm *r, unsigned long rate)
+{
+ u32 value = DIV_ROUND_UP(rate, 1000); /* to kHz */
+
+ return qcom_rpm_write(r->rpm, QCOM_RPM_SLEEP_STATE,
+ r->rpm_clk_id, &value, 1);
+}
+
+static void to_active_sleep(struct clk_rpm *r, unsigned long rate,
+ unsigned long *active, unsigned long *sleep)
+{
+ *active = rate;
+
+ /*
+ * Active-only clocks don't care what the rate is during sleep. So,
+ * they vote for zero.
+ */
+ if (r->active_only)
+ *sleep = 0;
+ else
+ *sleep = *active;
+}
+
+static int clk_rpm_prepare(struct clk_hw *hw)
+{
+ struct clk_rpm *r = to_clk_rpm(hw);
+ struct clk_rpm *peer = r->peer;
+ unsigned long this_rate = 0, this_sleep_rate = 0;
+ unsigned long peer_rate = 0, peer_sleep_rate = 0;
+ unsigned long active_rate, sleep_rate;
+ int ret = 0;
+
+ mutex_lock(&rpm_clk_lock);
+
+ /* Don't send requests to the RPM if the rate has not been set. */
+ if (!r->rate)
+ goto out;
+
+ to_active_sleep(r, r->rate, &this_rate, &this_sleep_rate);
+
+ /* Take peer clock's rate into account only if it's enabled. */
+ if (peer->enabled)
+ to_active_sleep(peer, peer->rate,
+ &peer_rate, &peer_sleep_rate);
+
+ active_rate = max(this_rate, peer_rate);
+
+ if (r->branch)
+ active_rate = !!active_rate;
+
+ ret = clk_rpm_set_rate_active(r, active_rate);
+ if (ret)
+ goto out;
+
+ sleep_rate = max(this_sleep_rate, peer_sleep_rate);
+ if (r->branch)
+ sleep_rate = !!sleep_rate;
+
+ ret = clk_rpm_set_rate_sleep(r, sleep_rate);
+ if (ret)
+ /* Undo the active set vote and restore it */
+ ret = clk_rpm_set_rate_active(r, peer_rate);
+
+out:
+ if (!ret)
+ r->enabled = true;
+
+ mutex_unlock(&rpm_clk_lock);
+
+ return ret;
+}
+
+static void clk_rpm_unprepare(struct clk_hw *hw)
+{
+ struct clk_rpm *r = to_clk_rpm(hw);
+ struct clk_rpm *peer = r->peer;
+ unsigned long peer_rate = 0, peer_sleep_rate = 0;
+ unsigned long active_rate, sleep_rate;
+ int ret;
+
+ mutex_lock(&rpm_clk_lock);
+
+ if (!r->rate)
+ goto out;
+
+ /* Take peer clock's rate into account only if it's enabled. */
+ if (peer->enabled)
+ to_active_sleep(peer, peer->rate, &peer_rate,
+ &peer_sleep_rate);
+
+ active_rate = r->branch ? !!peer_rate : peer_rate;
+ ret = clk_rpm_set_rate_active(r, active_rate);
+ if (ret)
+ goto out;
+
+ sleep_rate = r->branch ? !!peer_sleep_rate : peer_sleep_rate;
+ ret = clk_rpm_set_rate_sleep(r, sleep_rate);
+ if (ret)
+ goto out;
+
+ r->enabled = false;
+
+out:
+ mutex_unlock(&rpm_clk_lock);
+}
+
+static int clk_rpm_set_rate(struct clk_hw *hw,
+ unsigned long rate, unsigned long parent_rate)
+{
+ struct clk_rpm *r = to_clk_rpm(hw);
+ struct clk_rpm *peer = r->peer;
+ unsigned long active_rate, sleep_rate;
+ unsigned long this_rate = 0, this_sleep_rate = 0;
+ unsigned long peer_rate = 0, peer_sleep_rate = 0;
+ int ret = 0;
+
+ mutex_lock(&rpm_clk_lock);
+
+ if (!r->enabled)
+ goto out;
+
+ to_active_sleep(r, rate, &this_rate, &this_sleep_rate);
+
+ /* Take peer clock's rate into account only if it's enabled. */
+ if (peer->enabled)
+ to_active_sleep(peer, peer->rate,
+ &peer_rate, &peer_sleep_rate);
+
+ active_rate = max(this_rate, peer_rate);
+ ret = clk_rpm_set_rate_active(r, active_rate);
+ if (ret)
+ goto out;
+
+ sleep_rate = max(this_sleep_rate, peer_sleep_rate);
+ ret = clk_rpm_set_rate_sleep(r, sleep_rate);
+ if (ret)
+ goto out;
+
+ r->rate = rate;
+
+out:
+ mutex_unlock(&rpm_clk_lock);
+
+ return ret;
+}
+
+static long clk_rpm_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ /*
+ * RPM handles rate rounding and we don't have a way to
+ * know what the rate will be, so just return whatever
+ * rate is requested.
+ */
+ return rate;
+}
+
+static unsigned long clk_rpm_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_rpm *r = to_clk_rpm(hw);
+
+ /*
+ * RPM handles rate rounding and we don't have a way to
+ * know what the rate will be, so just return whatever
+ * rate was set.
+ */
+ return r->rate;
+}
+
+static const struct clk_ops clk_rpm_ops = {
+ .prepare = clk_rpm_prepare,
+ .unprepare = clk_rpm_unprepare,
+ .set_rate = clk_rpm_set_rate,
+ .round_rate = clk_rpm_round_rate,
+ .recalc_rate = clk_rpm_recalc_rate,
+};
+
+static const struct clk_ops clk_rpm_branch_ops = {
+ .prepare = clk_rpm_prepare,
+ .unprepare = clk_rpm_unprepare,
+ .round_rate = clk_rpm_round_rate,
+ .recalc_rate = clk_rpm_recalc_rate,
+};
+
+/* apq8064 */
+DEFINE_CLK_RPM_PXO_BRANCH(apq8064, pxo, pxo_a_clk, QCOM_RPM_PXO_CLK, 27000000);
+DEFINE_CLK_RPM_CXO_BRANCH(apq8064, cxo, cxo_a_clk, QCOM_RPM_CXO_CLK, 19200000);
+DEFINE_CLK_RPM(apq8064, afab_clk, afab_a_clk, QCOM_RPM_APPS_FABRIC_CLK);
+DEFINE_CLK_RPM(apq8064, cfpb_clk, cfpb_a_clk, QCOM_RPM_CFPB_CLK);
+DEFINE_CLK_RPM(apq8064, daytona_clk, daytona_a_clk, QCOM_RPM_DAYTONA_FABRIC_CLK);
+DEFINE_CLK_RPM(apq8064, ebi1_clk, ebi1_a_clk, QCOM_RPM_EBI1_CLK);
+DEFINE_CLK_RPM(apq8064, mmfab_clk, mmfab_a_clk, QCOM_RPM_MM_FABRIC_CLK);
+DEFINE_CLK_RPM(apq8064, mmfpb_clk, mmfpb_a_clk, QCOM_RPM_MMFPB_CLK);
+DEFINE_CLK_RPM(apq8064, sfab_clk, sfab_a_clk, QCOM_RPM_SYS_FABRIC_CLK);
+DEFINE_CLK_RPM(apq8064, sfpb_clk, sfpb_a_clk, QCOM_RPM_SFPB_CLK);
+DEFINE_CLK_RPM(apq8064, qdss_clk, qdss_a_clk, QCOM_RPM_QDSS_CLK);
+
+static struct clk_rpm *apq8064_clks[] = {
+ [RPM_PXO_CLK] = &apq8064_pxo,
+ [RPM_PXO_A_CLK] = &apq8064_pxo_a_clk,
+ [RPM_CXO_CLK] = &apq8064_cxo,
+ [RPM_CXO_A_CLK] = &apq8064_cxo_a_clk,
+ [RPM_APPS_FABRIC_CLK] = &apq8064_afab_clk,
+ [RPM_APPS_FABRIC_A_CLK] = &apq8064_afab_a_clk,
+ [RPM_CFPB_CLK] = &apq8064_cfpb_clk,
+ [RPM_CFPB_A_CLK] = &apq8064_cfpb_a_clk,
+ [RPM_DAYTONA_FABRIC_CLK] = &apq8064_daytona_clk,
+ [RPM_DAYTONA_FABRIC_A_CLK] = &apq8064_daytona_a_clk,
+ [RPM_EBI1_CLK] = &apq8064_ebi1_clk,
+ [RPM_EBI1_A_CLK] = &apq8064_ebi1_a_clk,
+ [RPM_MM_FABRIC_CLK] = &apq8064_mmfab_clk,
+ [RPM_MM_FABRIC_A_CLK] = &apq8064_mmfab_a_clk,
+ [RPM_MMFPB_CLK] = &apq8064_mmfpb_clk,
+ [RPM_MMFPB_A_CLK] = &apq8064_mmfpb_a_clk,
+ [RPM_SYS_FABRIC_CLK] = &apq8064_sfab_clk,
+ [RPM_SYS_FABRIC_A_CLK] = &apq8064_sfab_a_clk,
+ [RPM_SFPB_CLK] = &apq8064_sfpb_clk,
+ [RPM_SFPB_A_CLK] = &apq8064_sfpb_a_clk,
+ [RPM_QDSS_CLK] = &apq8064_qdss_clk,
+ [RPM_QDSS_A_CLK] = &apq8064_qdss_a_clk,
+};
+
+static const struct rpm_clk_desc rpm_clk_apq8064 = {
+ .clks = apq8064_clks,
+ .num_clks = ARRAY_SIZE(apq8064_clks),
+};
+
+static const struct of_device_id rpm_clk_match_table[] = {
+ { .compatible = "qcom,rpmcc-apq8064", .data = &rpm_clk_apq8064},
+ { }
+};
+MODULE_DEVICE_TABLE(of, rpm_clk_match_table);
+
+static int rpm_clk_probe(struct platform_device *pdev)
+{
+ struct clk **clks;
+ struct clk *clk;
+ struct rpm_cc *rcc;
+ struct clk_onecell_data *data;
+ int ret;
+ size_t num_clks, i;
+ struct qcom_rpm *rpm;
+ struct clk_rpm **rpm_clks;
+ const struct rpm_clk_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;
+
+ rpm_clks = desc->clks;
+ num_clks = desc->num_clks;
+
+ rcc = devm_kzalloc(&pdev->dev, sizeof(*rcc) + sizeof(*clks) * num_clks,
+ GFP_KERNEL);
+ if (!rcc)
+ return -ENOMEM;
+
+ clks = rcc->clks;
+ data = &rcc->data;
+ data->clks = clks;
+ data->clk_num = num_clks;
+
+ for (i = 0; i < num_clks; i++) {
+ if (!rpm_clks[i]) {
+ clks[i] = ERR_PTR(-ENOENT);
+ continue;
+ }
+
+ rpm_clks[i]->rpm = rpm;
+ clk = devm_clk_register(&pdev->dev, &rpm_clks[i]->hw);
+ if (IS_ERR(clk)) {
+ ret = PTR_ERR(clk);
+ goto err;
+ }
+
+ clks[i] = clk;
+ }
+
+ ret = of_clk_add_provider(pdev->dev.of_node, of_clk_src_onecell_get,
+ data);
+ if (ret)
+ goto err;
+
+ return 0;
+err:
+ dev_err(&pdev->dev, "Error registering RPM Clock driver (%d)\n", ret);
+ return ret;
+}
+
+static int rpm_clk_remove(struct platform_device *pdev)
+{
+ of_clk_del_provider(pdev->dev.of_node);
+ return 0;
+}
+
+static struct platform_driver rpm_clk_driver = {
+ .driver = {
+ .name = "qcom-clk-rpm",
+ .of_match_table = rpm_clk_match_table,
+ },
+ .probe = rpm_clk_probe,
+ .remove = rpm_clk_remove,
+};
+
+static int __init rpm_clk_init(void)
+{
+ return platform_driver_register(&rpm_clk_driver);
+}
+core_initcall(rpm_clk_init);
+
+static void __exit rpm_clk_exit(void)
+{
+ platform_driver_unregister(&rpm_clk_driver);
+}
+module_exit(rpm_clk_exit);
+
+MODULE_DESCRIPTION("Qualcomm RPM Clock Controller Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:qcom-clk-rpm");
diff --git a/include/dt-bindings/clock/qcom,rpmcc.h b/include/dt-bindings/clock/qcom,rpmcc.h
index 7800ab465d48..f6fd33372257 100644
--- a/include/dt-bindings/clock/qcom,rpmcc.h
+++ b/include/dt-bindings/clock/qcom,rpmcc.h
@@ -14,6 +14,30 @@
#ifndef _DT_BINDINGS_CLK_MSM_RPMCC_H
#define _DT_BINDINGS_CLK_MSM_RPMCC_H

+/* apq8064 */
+#define RPM_PXO_CLK 0
+#define RPM_PXO_A_CLK 1
+#define RPM_CXO_CLK 2
+#define RPM_CXO_A_CLK 3
+#define RPM_APPS_FABRIC_CLK 4
+#define RPM_APPS_FABRIC_A_CLK 5
+#define RPM_CFPB_CLK 6
+#define RPM_CFPB_A_CLK 7
+#define RPM_QDSS_CLK 8
+#define RPM_QDSS_A_CLK 9
+#define RPM_DAYTONA_FABRIC_CLK 10
+#define RPM_DAYTONA_FABRIC_A_CLK 11
+#define RPM_EBI1_CLK 12
+#define RPM_EBI1_A_CLK 13
+#define RPM_MM_FABRIC_CLK 14
+#define RPM_MM_FABRIC_A_CLK 15
+#define RPM_MMFPB_CLK 16
+#define RPM_MMFPB_A_CLK 17
+#define RPM_SYS_FABRIC_CLK 18
+#define RPM_SYS_FABRIC_A_CLK 19
+#define RPM_SFPB_CLK 20
+#define RPM_SFPB_A_CLK 21
+
/* msm8916 */
#define RPM_XO_CLK_SRC 0
#define RPM_XO_A_CLK_SRC 1