Add SDPM clock monitor driver, which will register for clock rate
change notification and write the clock rate into SDPM CSR register.
Signed-off-by: Ram Chandrasekar <rkumbako@xxxxxxxxxxxxxx>
Signed-off-by: Manaf Meethalavalappu Pallikunhi <manafm@xxxxxxxxxxxxxx>
---
drivers/soc/qcom/Kconfig | 8 ++
drivers/soc/qcom/Makefile | 1 +
drivers/soc/qcom/sdpm_clk_monitor.c | 217 ++++++++++++++++++++++++++++++++++++
3 files changed, 226 insertions(+)
create mode 100644 drivers/soc/qcom/sdpm_clk_monitor.c
diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
index 9464ff4..1f04d69 100644
--- a/drivers/soc/qcom/Kconfig
+++ b/drivers/soc/qcom/Kconfig
@@ -237,4 +237,12 @@ config QCOM_APR
used by audio driver to configure QDSP6
ASM, ADM and AFE modules.
+config QCOM_SDPM_CLOCK_MONITOR
+ tristate "Qualcomm SDPM Clock Monitor"
+ depends on COMMON_CLK
+ help
+ This enables the Qualcomm SDPM Clock Monitor. This driver can register
+ for different clock rate change notifications and write the clock
+ rate into the SDPM CSR register. This driver will receive the clock
+ list and the CSR details from devicetree.
endmenu
diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index d658a10..4eef767 100644
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -29,3 +29,4 @@ obj-$(CONFIG_QCOM_RPMPD) += rpmpd.o
obj-$(CONFIG_QCOM_KRYO_L2_ACCESSORS) += kryo-l2-accessors.o
obj-$(CONFIG_QCOM_LLCC_PERFMON) += llcc_perfmon.o
obj-$(CONFIG_QCOM_MEMORY_DUMP_V2) += memory_dump_v2.o
+obj-$(CONFIG_QCOM_SDPM_CLOCK_MONITOR) += sdpm_clk_monitor.o
diff --git a/drivers/soc/qcom/sdpm_clk_monitor.c b/drivers/soc/qcom/sdpm_clk_monitor.c
new file mode 100644
index 00000000..1aee119
--- /dev/null
+++ b/drivers/soc/qcom/sdpm_clk_monitor.c
@@ -0,0 +1,217 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2021, The Linux Foundation. All rights reserved.
+ */
+
+#define pr_fmt(fmt) "%s " fmt, KBUILD_MODNAME
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define SDPM_DRIVER "sdpm-clk-monitor"
+#define CSR_MAX_VAL 7
+#define CSR_OFFSET 0xF00
+#define FREQ_HZ_TO_MHZ(f) DIV_ROUND_UP((f), 1000000)
+#define SDPM_CSR_OFFSET(id) (CSR_OFFSET + (id * 4))
+
+struct sdpm_clk_instance;
+struct sdpm_clk_data {
+ struct list_head sdpm_node;
+ struct notifier_block clk_rate_nb;
+ struct clk *clk;
+ const char *clock_name;
+ uint32_t csr_id;
+ struct sdpm_clk_instance *sdpm_inst;
+};
+
+struct sdpm_clk_instance {
+ struct device *dev;
+ void __iomem *regmap;
+ struct list_head sdpm_instances;
+};
+
+static void sdpm_csr_write(struct sdpm_clk_data *sdpm_data,
+ unsigned long clk_rate)
+{
+ struct sdpm_clk_instance *sdpm_inst = sdpm_data->sdpm_inst;
+
+ writel_relaxed(clk_rate, sdpm_inst->regmap +
+ SDPM_CSR_OFFSET(sdpm_data->csr_id));
+ dev_dbg(sdpm_inst->dev, "clock:%s offset:0x%x frequency:%u\n",
+ sdpm_data->clock_name,
+ SDPM_CSR_OFFSET(sdpm_data->csr_id),
+ clk_rate);
+}
+
+static int sdpm_clock_notifier(struct notifier_block *nb,
+ unsigned long event, void *data)
+{
+ struct clk_notifier_data *ndata = data;
+ struct sdpm_clk_data *sdpm_data = container_of(nb,
+ struct sdpm_clk_data, clk_rate_nb);
+
+ dev_dbg(sdpm_data->sdpm_inst->dev, "clock:%s event:%lu\n",
+ sdpm_data->clock_name, event);
+ switch (event) {
+ case PRE_RATE_CHANGE:
+ if (ndata->new_rate > ndata->old_rate)
+ sdpm_csr_write(sdpm_data,
+ FREQ_HZ_TO_MHZ(ndata->new_rate));
+ return NOTIFY_DONE;
+ case POST_RATE_CHANGE:
+ if (ndata->new_rate < ndata->old_rate)
+ sdpm_csr_write(sdpm_data,
+ FREQ_HZ_TO_MHZ(ndata->new_rate));
+ return NOTIFY_DONE;
+ case ABORT_RATE_CHANGE:
+ if (ndata->new_rate > ndata->old_rate)
+ sdpm_csr_write(sdpm_data,
+ FREQ_HZ_TO_MHZ(ndata->old_rate));
+ return NOTIFY_DONE;
+ default:
+ return NOTIFY_DONE;
+ }
+}
+
+static int sdpm_clk_device_remove(struct platform_device *pdev)
+{
+ struct sdpm_clk_instance *sdpm_inst =
+ (struct sdpm_clk_instance *)dev_get_drvdata(&pdev->dev);
+ struct sdpm_clk_data *sdpm_data = NULL, *next = NULL;
+
+ list_for_each_entry_safe(sdpm_data, next,
+ &sdpm_inst->sdpm_instances, sdpm_node) {
+ clk_notifier_unregister(sdpm_data->clk,
+ &sdpm_data->clk_rate_nb);
+ list_del(&sdpm_data->sdpm_node);
+ }
+
+ return 0;
+}
+
+static int sdpm_clk_device_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *dev_node = dev->of_node;
+ int ret = 0, idx = 0, clk_ct = 0, csr = 0, csr_ct = 0;
+ struct sdpm_clk_instance *sdpm_inst = NULL;
+ struct sdpm_clk_data *sdpm_data = NULL;
+ struct resource *res;
+
+ sdpm_inst = devm_kzalloc(dev, sizeof(*sdpm_inst), GFP_KERNEL);
+ if (!sdpm_inst)
+ return -ENOMEM;
+ sdpm_inst->dev = dev;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(dev, "Couldn't get MEM resource\n");
+ return -EINVAL;
+ }
+ dev_dbg(dev, "sdpm@0x%x size:%d\n", res->start,
+ resource_size(res));
+ dev_set_drvdata(dev, sdpm_inst);
+
+ sdpm_inst->regmap = devm_ioremap_resource(dev, res);
+ if (!sdpm_inst->regmap) {
+ dev_err(dev, "Couldn't get regmap\n");
+ return -EINVAL;
+ }
+
+ ret = of_property_count_strings(dev_node, "clock-names");
+ if (ret <= 0) {
+ dev_err(dev, "Couldn't get clock names. %d\n", ret);
+ return ret;
+ }
+ clk_ct = ret;
+ ret = of_property_count_u32_elems(dev_node, "csr-id");
+ if (ret <= 0) {
+ dev_err(dev, "Couldn't get csr ID array. %d\n", ret);
+ return ret;
+ }
+ csr_ct = ret;
+
+ if (csr_ct != clk_ct) {
+ dev_err(dev, "Invalid csr:%d and clk:%d count.\n", csr_ct,
+ clk_ct);
+ return -EINVAL;
+ }
+
+ INIT_LIST_HEAD(&sdpm_inst->sdpm_instances);
+
+ for (idx = 0; idx < clk_ct; idx++) {
+
+ sdpm_data = devm_kzalloc(dev, sizeof(*sdpm_data), GFP_KERNEL);
+ if (!sdpm_data) {
+ ret = -ENOMEM;
+ goto clk_err_exit;
+ }
+
+ ret = of_property_read_string_index(dev_node, "clock-names",
+ idx, &sdpm_data->clock_name);
+ if (ret < 0) {
+ dev_err(dev, "Couldn't get clk name index:%d. %d\n",
+ idx, ret);
+ goto clk_err_exit;
+ }
+
+ sdpm_data->clk = devm_clk_get(dev, sdpm_data->clock_name);
+ if (IS_ERR(sdpm_data->clk)) {
+ ret = PTR_ERR(sdpm_data->clk);
+ goto clk_err_exit;
+ }
+
+ ret = of_property_read_u32_index(dev_node, "csr-id", idx, &csr);
+ if (ret < 0) {
+ dev_err(dev, "Couldn't get CSR for index:%d. %d\n",
+ idx, ret);
+ goto clk_err_exit;
+ }
+
+ if (ret > CSR_MAX_VAL) {
+ dev_err(dev, "Invalid CSR %d\n", csr);
+ ret = -EINVAL;
+ goto clk_err_exit;
+ }
+
+ dev_dbg(dev, "SDPM clock:%s csr:%d initialized\n",
+ sdpm_data->clock_name, csr);
+ sdpm_data->csr_id = csr;
+ sdpm_data->sdpm_inst = sdpm_inst;
+ sdpm_data->clk_rate_nb.notifier_call = sdpm_clock_notifier;
+ sdpm_csr_write(sdpm_data,
+ FREQ_HZ_TO_MHZ(clk_get_rate(sdpm_data->clk)));
+ clk_notifier_register(sdpm_data->clk, &sdpm_data->clk_rate_nb);
+ list_add(&sdpm_data->sdpm_node, &sdpm_inst->sdpm_instances);
+ }
+
+ return 0;
+
+clk_err_exit:
+ sdpm_clk_device_remove(pdev);
+
+ return ret;
+}
+
+static const struct of_device_id sdpm_clk_device_match[] = {
+ {.compatible = "qcom,sdpm"},
+ {}
+};
+
+static struct platform_driver sdpm_clk_device_driver = {
+ .probe = sdpm_clk_device_probe,
+ .remove = sdpm_clk_device_remove,
+ .driver = {
+ .name = SDPM_DRIVER,
+ .of_match_table = sdpm_clk_device_match,
+ },
+};
+module_platform_driver(sdpm_clk_device_driver);
+
+MODULE_DESCRIPTION("Qualcomm Technologies, Inc. SDPM Clock Monitor Driver");
+MODULE_LICENSE("GPL v2");
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
