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path: root/drivers/cpufreq/imx-cpufreq-dt.c
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Diffstat (limited to 'drivers/cpufreq/imx-cpufreq-dt.c')
-rw-r--r--drivers/cpufreq/imx-cpufreq-dt.c97
1 files changed, 97 insertions, 0 deletions
diff --git a/drivers/cpufreq/imx-cpufreq-dt.c b/drivers/cpufreq/imx-cpufreq-dt.c
new file mode 100644
index 000000000000..b54fd26ea7df
--- /dev/null
+++ b/drivers/cpufreq/imx-cpufreq-dt.c
@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 NXP
+ */
+
+#include <linux/cpu.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/nvmem-consumer.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_opp.h>
+#include <linux/slab.h>
+
+#define OCOTP_CFG3_SPEED_GRADE_SHIFT 8
+#define OCOTP_CFG3_SPEED_GRADE_MASK (0x3 << 8)
+#define OCOTP_CFG3_MKT_SEGMENT_SHIFT 6
+#define OCOTP_CFG3_MKT_SEGMENT_MASK (0x3 << 6)
+
+/* cpufreq-dt device registered by imx-cpufreq-dt */
+static struct platform_device *cpufreq_dt_pdev;
+static struct opp_table *cpufreq_opp_table;
+
+static int imx_cpufreq_dt_probe(struct platform_device *pdev)
+{
+ struct device *cpu_dev = get_cpu_device(0);
+ u32 cell_value, supported_hw[2];
+ int speed_grade, mkt_segment;
+ int ret;
+
+ ret = nvmem_cell_read_u32(cpu_dev, "speed_grade", &cell_value);
+ if (ret)
+ return ret;
+
+ speed_grade = (cell_value & OCOTP_CFG3_SPEED_GRADE_MASK) >> OCOTP_CFG3_SPEED_GRADE_SHIFT;
+ mkt_segment = (cell_value & OCOTP_CFG3_MKT_SEGMENT_MASK) >> OCOTP_CFG3_MKT_SEGMENT_SHIFT;
+
+ /*
+ * Early samples without fuses written report "0 0" which means
+ * consumer segment and minimum speed grading.
+ *
+ * According to datasheet minimum speed grading is not supported for
+ * consumer parts so clamp to 1 to avoid warning for "no OPPs"
+ *
+ * Applies to 8mq and 8mm.
+ */
+ if (mkt_segment == 0 && speed_grade == 0 && (
+ of_machine_is_compatible("fsl,imx8mm") ||
+ of_machine_is_compatible("fsl,imx8mq")))
+ speed_grade = 1;
+
+ supported_hw[0] = BIT(speed_grade);
+ supported_hw[1] = BIT(mkt_segment);
+ dev_info(&pdev->dev, "cpu speed grade %d mkt segment %d supported-hw %#x %#x\n",
+ speed_grade, mkt_segment, supported_hw[0], supported_hw[1]);
+
+ cpufreq_opp_table = dev_pm_opp_set_supported_hw(cpu_dev, supported_hw, 2);
+ if (IS_ERR(cpufreq_opp_table)) {
+ ret = PTR_ERR(cpufreq_opp_table);
+ dev_err(&pdev->dev, "Failed to set supported opp: %d\n", ret);
+ return ret;
+ }
+
+ cpufreq_dt_pdev = platform_device_register_data(
+ &pdev->dev, "cpufreq-dt", -1, NULL, 0);
+ if (IS_ERR(cpufreq_dt_pdev)) {
+ dev_pm_opp_put_supported_hw(cpufreq_opp_table);
+ ret = PTR_ERR(cpufreq_dt_pdev);
+ dev_err(&pdev->dev, "Failed to register cpufreq-dt: %d\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int imx_cpufreq_dt_remove(struct platform_device *pdev)
+{
+ platform_device_unregister(cpufreq_dt_pdev);
+ dev_pm_opp_put_supported_hw(cpufreq_opp_table);
+
+ return 0;
+}
+
+static struct platform_driver imx_cpufreq_dt_driver = {
+ .probe = imx_cpufreq_dt_probe,
+ .remove = imx_cpufreq_dt_remove,
+ .driver = {
+ .name = "imx-cpufreq-dt",
+ },
+};
+module_platform_driver(imx_cpufreq_dt_driver);
+
+MODULE_ALIAS("platform:imx-cpufreq-dt");
+MODULE_DESCRIPTION("Freescale i.MX cpufreq speed grading driver");
+MODULE_LICENSE("GPL v2");