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path: root/drivers/devfreq/event/exynos-nocp.c
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Diffstat (limited to 'drivers/devfreq/event/exynos-nocp.c')
-rw-r--r--drivers/devfreq/event/exynos-nocp.c304
1 files changed, 304 insertions, 0 deletions
diff --git a/drivers/devfreq/event/exynos-nocp.c b/drivers/devfreq/event/exynos-nocp.c
new file mode 100644
index 000000000000..6b6a5f310486
--- /dev/null
+++ b/drivers/devfreq/event/exynos-nocp.c
@@ -0,0 +1,304 @@
+/*
+ * exynos-nocp.c - EXYNOS NoC (Network On Chip) Probe support
+ *
+ * Copyright (c) 2016 Samsung Electronics Co., Ltd.
+ * Author : Chanwoo Choi <cw00.choi@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/devfreq-event.h>
+#include <linux/kernel.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include "exynos-nocp.h"
+
+struct exynos_nocp {
+ struct devfreq_event_dev *edev;
+ struct devfreq_event_desc desc;
+
+ struct device *dev;
+
+ struct regmap *regmap;
+ struct clk *clk;
+};
+
+/*
+ * The devfreq-event ops structure for nocp probe.
+ */
+static int exynos_nocp_set_event(struct devfreq_event_dev *edev)
+{
+ struct exynos_nocp *nocp = devfreq_event_get_drvdata(edev);
+ int ret;
+
+ /* Disable NoC probe */
+ ret = regmap_update_bits(nocp->regmap, NOCP_MAIN_CTL,
+ NOCP_MAIN_CTL_STATEN_MASK, 0);
+ if (ret < 0) {
+ dev_err(nocp->dev, "failed to disable the NoC probe device\n");
+ return ret;
+ }
+
+ /* Set a statistics dump period to 0 */
+ ret = regmap_write(nocp->regmap, NOCP_STAT_PERIOD, 0x0);
+ if (ret < 0)
+ goto out;
+
+ /* Set the IntEvent fields of *_SRC */
+ ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_0_SRC,
+ NOCP_CNT_SRC_INTEVENT_MASK,
+ NOCP_CNT_SRC_INTEVENT_BYTE_MASK);
+ if (ret < 0)
+ goto out;
+
+ ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_1_SRC,
+ NOCP_CNT_SRC_INTEVENT_MASK,
+ NOCP_CNT_SRC_INTEVENT_CHAIN_MASK);
+ if (ret < 0)
+ goto out;
+
+ ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_2_SRC,
+ NOCP_CNT_SRC_INTEVENT_MASK,
+ NOCP_CNT_SRC_INTEVENT_CYCLE_MASK);
+ if (ret < 0)
+ goto out;
+
+ ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_3_SRC,
+ NOCP_CNT_SRC_INTEVENT_MASK,
+ NOCP_CNT_SRC_INTEVENT_CHAIN_MASK);
+ if (ret < 0)
+ goto out;
+
+
+ /* Set an alarm with a max/min value of 0 to generate StatALARM */
+ ret = regmap_write(nocp->regmap, NOCP_STAT_ALARM_MIN, 0x0);
+ if (ret < 0)
+ goto out;
+
+ ret = regmap_write(nocp->regmap, NOCP_STAT_ALARM_MAX, 0x0);
+ if (ret < 0)
+ goto out;
+
+ /* Set AlarmMode */
+ ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_0_ALARM_MODE,
+ NOCP_CNT_ALARM_MODE_MASK,
+ NOCP_CNT_ALARM_MODE_MIN_MAX_MASK);
+ if (ret < 0)
+ goto out;
+
+ ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_1_ALARM_MODE,
+ NOCP_CNT_ALARM_MODE_MASK,
+ NOCP_CNT_ALARM_MODE_MIN_MAX_MASK);
+ if (ret < 0)
+ goto out;
+
+ ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_2_ALARM_MODE,
+ NOCP_CNT_ALARM_MODE_MASK,
+ NOCP_CNT_ALARM_MODE_MIN_MAX_MASK);
+ if (ret < 0)
+ goto out;
+
+ ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_3_ALARM_MODE,
+ NOCP_CNT_ALARM_MODE_MASK,
+ NOCP_CNT_ALARM_MODE_MIN_MAX_MASK);
+ if (ret < 0)
+ goto out;
+
+ /* Enable the measurements by setting AlarmEn and StatEn */
+ ret = regmap_update_bits(nocp->regmap, NOCP_MAIN_CTL,
+ NOCP_MAIN_CTL_STATEN_MASK | NOCP_MAIN_CTL_ALARMEN_MASK,
+ NOCP_MAIN_CTL_STATEN_MASK | NOCP_MAIN_CTL_ALARMEN_MASK);
+ if (ret < 0)
+ goto out;
+
+ /* Set GlobalEN */
+ ret = regmap_update_bits(nocp->regmap, NOCP_CFG_CTL,
+ NOCP_CFG_CTL_GLOBALEN_MASK,
+ NOCP_CFG_CTL_GLOBALEN_MASK);
+ if (ret < 0)
+ goto out;
+
+ /* Enable NoC probe */
+ ret = regmap_update_bits(nocp->regmap, NOCP_MAIN_CTL,
+ NOCP_MAIN_CTL_STATEN_MASK,
+ NOCP_MAIN_CTL_STATEN_MASK);
+ if (ret < 0)
+ goto out;
+
+ return 0;
+
+out:
+ /* Reset NoC probe */
+ if (regmap_update_bits(nocp->regmap, NOCP_MAIN_CTL,
+ NOCP_MAIN_CTL_STATEN_MASK, 0)) {
+ dev_err(nocp->dev, "Failed to reset NoC probe device\n");
+ }
+
+ return ret;
+}
+
+static int exynos_nocp_get_event(struct devfreq_event_dev *edev,
+ struct devfreq_event_data *edata)
+{
+ struct exynos_nocp *nocp = devfreq_event_get_drvdata(edev);
+ unsigned int counter[4];
+ int ret;
+
+ /* Read cycle count */
+ ret = regmap_read(nocp->regmap, NOCP_COUNTERS_0_VAL, &counter[0]);
+ if (ret < 0)
+ goto out;
+
+ ret = regmap_read(nocp->regmap, NOCP_COUNTERS_1_VAL, &counter[1]);
+ if (ret < 0)
+ goto out;
+
+ ret = regmap_read(nocp->regmap, NOCP_COUNTERS_2_VAL, &counter[2]);
+ if (ret < 0)
+ goto out;
+
+ ret = regmap_read(nocp->regmap, NOCP_COUNTERS_3_VAL, &counter[3]);
+ if (ret < 0)
+ goto out;
+
+ edata->load_count = ((counter[1] << 16) | counter[0]);
+ edata->total_count = ((counter[3] << 16) | counter[2]);
+
+ dev_dbg(&edev->dev, "%s (event: %ld/%ld)\n", edev->desc->name,
+ edata->load_count, edata->total_count);
+
+ return 0;
+
+out:
+ edata->load_count = 0;
+ edata->total_count = 0;
+
+ dev_err(nocp->dev, "Failed to read the counter of NoC probe device\n");
+
+ return ret;
+}
+
+static const struct devfreq_event_ops exynos_nocp_ops = {
+ .set_event = exynos_nocp_set_event,
+ .get_event = exynos_nocp_get_event,
+};
+
+static const struct of_device_id exynos_nocp_id_match[] = {
+ { .compatible = "samsung,exynos5420-nocp", },
+ { /* sentinel */ },
+};
+
+static struct regmap_config exynos_nocp_regmap_config = {
+ .reg_bits = 32,
+ .val_bits = 32,
+ .reg_stride = 4,
+ .max_register = NOCP_COUNTERS_3_VAL,
+};
+
+static int exynos_nocp_parse_dt(struct platform_device *pdev,
+ struct exynos_nocp *nocp)
+{
+ struct device *dev = nocp->dev;
+ struct device_node *np = dev->of_node;
+ struct resource *res;
+ void __iomem *base;
+
+ if (!np) {
+ dev_err(dev, "failed to find devicetree node\n");
+ return -EINVAL;
+ }
+
+ nocp->clk = devm_clk_get(dev, "nocp");
+ if (IS_ERR(nocp->clk))
+ nocp->clk = NULL;
+
+ /* Maps the memory mapped IO to control nocp register */
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (IS_ERR(res))
+ return PTR_ERR(res);
+
+ base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ exynos_nocp_regmap_config.max_register = resource_size(res) - 4;
+
+ nocp->regmap = devm_regmap_init_mmio(dev, base,
+ &exynos_nocp_regmap_config);
+ if (IS_ERR(nocp->regmap)) {
+ dev_err(dev, "failed to initialize regmap\n");
+ return PTR_ERR(nocp->regmap);
+ }
+
+ return 0;
+}
+
+static int exynos_nocp_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct exynos_nocp *nocp;
+ int ret;
+
+ nocp = devm_kzalloc(&pdev->dev, sizeof(*nocp), GFP_KERNEL);
+ if (!nocp)
+ return -ENOMEM;
+
+ nocp->dev = &pdev->dev;
+
+ /* Parse dt data to get resource */
+ ret = exynos_nocp_parse_dt(pdev, nocp);
+ if (ret < 0) {
+ dev_err(&pdev->dev,
+ "failed to parse devicetree for resource\n");
+ return ret;
+ }
+
+ /* Add devfreq-event device to measure the bandwidth of NoC */
+ nocp->desc.ops = &exynos_nocp_ops;
+ nocp->desc.driver_data = nocp;
+ nocp->desc.name = np->full_name;
+ nocp->edev = devm_devfreq_event_add_edev(&pdev->dev, &nocp->desc);
+ if (IS_ERR(nocp->edev)) {
+ dev_err(&pdev->dev,
+ "failed to add devfreq-event device\n");
+ return PTR_ERR(nocp->edev);
+ }
+ platform_set_drvdata(pdev, nocp);
+
+ clk_prepare_enable(nocp->clk);
+
+ pr_info("exynos-nocp: new NoC Probe device registered: %s\n",
+ dev_name(dev));
+
+ return 0;
+}
+
+static int exynos_nocp_remove(struct platform_device *pdev)
+{
+ struct exynos_nocp *nocp = platform_get_drvdata(pdev);
+
+ clk_disable_unprepare(nocp->clk);
+
+ return 0;
+}
+
+static struct platform_driver exynos_nocp_driver = {
+ .probe = exynos_nocp_probe,
+ .remove = exynos_nocp_remove,
+ .driver = {
+ .name = "exynos-nocp",
+ .of_match_table = exynos_nocp_id_match,
+ },
+};
+module_platform_driver(exynos_nocp_driver);
+
+MODULE_DESCRIPTION("Exynos NoC (Network on Chip) Probe driver");
+MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
+MODULE_LICENSE("GPL");