Add a driver for the SDX55 APCS clock controller. It is part of the APCS
hardware block, which among other things implements also a combined mux
and half integer divider functionality. The APCS clock controller has 3
parent clocks:
1. Board XO
2. Fixed rate GPLL0
3. A7 PLL
This is required for enabling CPU frequency scaling on SDX55-based
platforms.
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasi...@linaro.org>
---
drivers/clk/qcom/Kconfig | 9 ++
drivers/clk/qcom/Makefile | 1 +
drivers/clk/qcom/apcs-sdx55.c | 149 ++++++++++++++++++++++++++++++++++
3 files changed, 159 insertions(+)
create mode 100644 drivers/clk/qcom/apcs-sdx55.c
diff --git a/drivers/clk/qcom/Kconfig b/drivers/clk/qcom/Kconfig
index d6f4aee4427a..ac43b715bff6 100644
--- a/drivers/clk/qcom/Kconfig
+++ b/drivers/clk/qcom/Kconfig
@@ -54,6 +54,15 @@ config QCOM_CLK_APCC_MSM8996
Say Y if you want to support CPU clock scaling using CPUfreq
drivers for dynamic power management.
+config QCOM_CLK_APCS_SDX55
+ tristate "SDX55 APCS Clock Controller"
+ depends on QCOM_APCS_IPC || COMPILE_TEST
+ help
+ Support for the APCS Clock Controller on SDX55 platform. The
+ APCS is managing the mux and divider which feeds the CPUs.
+ Say Y if you want to support CPU frequency scaling on devices
+ such as SDX55.
+
config QCOM_CLK_RPM
tristate "RPM based Clock Controller"
depends on MFD_QCOM_RPM
diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
index e7e0ac382176..4de926da4b15 100644
--- a/drivers/clk/qcom/Makefile
+++ b/drivers/clk/qcom/Makefile
@@ -47,6 +47,7 @@ obj-$(CONFIG_QCOM_A53PLL) += a53-pll.o
obj-$(CONFIG_QCOM_A7PLL) += a7-pll.o
obj-$(CONFIG_QCOM_CLK_APCS_MSM8916) += apcs-msm8916.o
obj-$(CONFIG_QCOM_CLK_APCC_MSM8996) += clk-cpu-8996.o
+obj-$(CONFIG_QCOM_CLK_APCS_SDX55) += apcs-sdx55.o
obj-$(CONFIG_QCOM_CLK_RPM) += clk-rpm.o
obj-$(CONFIG_QCOM_CLK_RPMH) += clk-rpmh.o
obj-$(CONFIG_QCOM_CLK_SMD_RPM) += clk-smd-rpm.o
diff --git a/drivers/clk/qcom/apcs-sdx55.c b/drivers/clk/qcom/apcs-sdx55.c
new file mode 100644
index 000000000000..e111e124cb7a
--- /dev/null
+++ b/drivers/clk/qcom/apcs-sdx55.c
@@ -0,0 +1,149 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Qualcomm SDX55 APCS clock controller driver
+ *
+ * Copyright (c) 2020, Linaro Limited
+ * Author: Manivannan Sadhasivam <manivannan.sadhasi...@linaro.org>
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/cpu.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#include "clk-regmap.h"
+#include "clk-regmap-mux-div.h"
+
+static const u32 apcs_mux_clk_parent_map[] = { 0, 1, 5 };
+
+static const struct clk_parent_data pdata[] = {
+ { .fw_name = "ref" },
+ { .fw_name = "aux" },
+ { .fw_name = "pll" },
+};
+
+/*
+ * We use the notifier function for switching to a temporary safe configuration
+ * (mux and divider), while the A7 PLL is reconfigured.
+ */
+static int a7cc_notifier_cb(struct notifier_block *nb, unsigned long event,
+ void *data)
+{
+ int ret = 0;
+ struct clk_regmap_mux_div *md = container_of(nb,
+ struct clk_regmap_mux_div,
+ clk_nb);
+ if (event == PRE_RATE_CHANGE)
+ /* set the mux and divider to safe frequency (400mhz) */
+ ret = mux_div_set_src_div(md, 1, 2);
+
+ return notifier_from_errno(ret);
+}
+
+static int qcom_apcs_sdx55_clk_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device *parent = dev->parent;
+ struct device *cpu_dev;
+ struct clk_regmap_mux_div *a7cc;
+ struct regmap *regmap;
+ struct clk_init_data init = { };
+ int ret;
+
+ regmap = dev_get_regmap(parent, NULL);
+ if (!regmap) {
+ dev_err_probe(dev, ret, "Failed to get parent regmap\n");
+ return -ENODEV;
+ }
+
+ a7cc = devm_kzalloc(dev, sizeof(*a7cc), GFP_KERNEL);
+ if (!a7cc)
+ return -ENOMEM;
+
+ init.name = "a7mux";
+ init.parent_data = pdata;
+ init.num_parents = ARRAY_SIZE(pdata);
+ init.ops = &clk_regmap_mux_div_ops;
+
+ a7cc->clkr.hw.init = &init;
+ a7cc->clkr.regmap = regmap;
+ a7cc->reg_offset = 0x8;
+ a7cc->hid_width = 5;
+ a7cc->hid_shift = 0;
+ a7cc->src_width = 3;
+ a7cc->src_shift = 8;
+ a7cc->parent_map = apcs_mux_clk_parent_map;
+
+ a7cc->pclk = devm_clk_get(parent, "pll");
+ if (IS_ERR(a7cc->pclk)) {
+ ret = PTR_ERR(a7cc->pclk);
+ if (ret != -EPROBE_DEFER)
+ dev_err_probe(dev, ret, "Failed to get PLL clk\n");
+ return ret;
+ }
+
+ a7cc->clk_nb.notifier_call = a7cc_notifier_cb;
+ ret = clk_notifier_register(a7cc->pclk, &a7cc->clk_nb);
+ if (ret) {
+ dev_err_probe(dev, ret, "Failed to register clock notifier\n");
+ return ret;
+ }
+
+ ret = devm_clk_register_regmap(dev, &a7cc->clkr);
+ if (ret) {
+ dev_err_probe(dev, ret, "Failed to register regmap clock\n");
+ goto err;
+ }
+
+ ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
+ &a7cc->clkr.hw);
+ if (ret) {
+ dev_err_probe(dev, ret, "Failed to add clock provider\n");
+ goto err;
+ }
+
+ platform_set_drvdata(pdev, a7cc);
+
+ /*
+ * Attach the power domain to cpudev. Since there is no dedicated driver
+ * for CPUs and the SDX55 platform lacks hardware specific CPUFreq
+ * driver, there seems to be no better place to do this. So do it here!
+ */
+ cpu_dev = get_cpu_device(0);
+ dev_pm_domain_attach(cpu_dev, true);
+
+ return 0;
+
+err:
+ clk_notifier_unregister(a7cc->pclk, &a7cc->clk_nb);
+ return ret;
+}
+
+static int qcom_apcs_sdx55_clk_remove(struct platform_device *pdev)
+{
+ struct device *cpu_dev = get_cpu_device(0);
+ struct clk_regmap_mux_div *a7cc = platform_get_drvdata(pdev);
+
+ clk_notifier_unregister(a7cc->pclk, &a7cc->clk_nb);
+ dev_pm_domain_detach(cpu_dev, true);
+
+ return 0;
+}
+
+static struct platform_driver qcom_apcs_sdx55_clk_driver = {
+ .probe = qcom_apcs_sdx55_clk_probe,
+ .remove = qcom_apcs_sdx55_clk_remove,
+ .driver = {
+ .name = "qcom-sdx55-acps-clk",
+ },
+};
+module_platform_driver(qcom_apcs_sdx55_clk_driver);
+
+MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasi...@linaro.org>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Qualcomm SDX55 APCS clock driver");
--
2.25.1
