clk: qcom: Add support for RPM Clocks

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>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

1 files changed, 489 insertions, 0 deletions

diff --git a/drivers/clk/qcom/clk-rpm.c b/drivers/clk/qcom/clk-rpm.c
new file mode 100644
index 000000000000..1950a9572624
--- /dev/null
+++ b/drivers/clk/qcom/clk-rpm.c
@@ -0,0 +1,489 @@
+/*
+ * 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_hw_onecell_data data;
+	struct clk_hw *hws[];
+};
+
+struct rpm_clk_desc {
+	struct clk_rpm **clks;
+	size_t num_clks;
+};
+
+static DEFINE_MUTEX(rpm_clk_lock);
+
+static int clk_rpm_handoff(struct clk_rpm *r)
+{
+	int ret;
+	u32 value = INT_MAX;
+
+	ret = qcom_rpm_write(r->rpm, QCOM_RPM_ACTIVE_STATE,
+			     r->rpm_clk_id, &value, 1);
+	if (ret)
+		return ret;
+	ret = qcom_rpm_write(r->rpm, QCOM_RPM_SLEEP_STATE,
+			     r->rpm_clk_id, &value, 1);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+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(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_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_hw **hws;
+	struct rpm_cc *rcc;
+	struct clk_hw_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(*hws) * num_clks,
+			   GFP_KERNEL);
+	if (!rcc)
+		return -ENOMEM;
+
+	hws = rcc->hws;
+	data = &rcc->data;
+	data->num = num_clks;
+
+	for (i = 0; i < num_clks; i++) {
+		if (!rpm_clks[i])
+			continue;
+
+		rpm_clks[i]->rpm = rpm;
+
+		ret = clk_rpm_handoff(rpm_clks[i]);
+		if (ret)
+			goto err;
+	}
+
+	for (i = 0; i < num_clks; i++) {
+		if (!rpm_clks[i]) {
+			data->hws[i] = ERR_PTR(-ENOENT);
+			continue;
+		}
+
+		ret = devm_clk_hw_register(&pdev->dev, &rpm_clks[i]->hw);
+		if (ret)
+			goto err;
+	}
+
+	ret = of_clk_add_hw_provider(pdev->dev.of_node, of_clk_hw_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");