Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 384 insertions, 0 deletions

diff --git a/drivers/clk/bcm/clk-raspberrypi.c b/drivers/clk/bcm/clk-raspberrypi.c
new file mode 100644
index 000000000..969227e2d
--- /dev/null
+++ b/drivers/clk/bcm/clk-raspberrypi.c
@@ -0,0 +1,384 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Raspberry Pi driver for firmware controlled clocks
+ *
+ * Even though clk-bcm2835 provides an interface to the hardware registers for
+ * the system clocks we've had to factor out 'pllb' as the firmware 'owns' it.
+ * We're not allowed to change it directly as we might race with the
+ * over-temperature and under-voltage protections provided by the firmware.
+ *
+ * Copyright (C) 2019 Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
+ */
+
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include <soc/bcm2835/raspberrypi-firmware.h>
+
+enum rpi_firmware_clk_id {
+	RPI_FIRMWARE_EMMC_CLK_ID = 1,
+	RPI_FIRMWARE_UART_CLK_ID,
+	RPI_FIRMWARE_ARM_CLK_ID,
+	RPI_FIRMWARE_CORE_CLK_ID,
+	RPI_FIRMWARE_V3D_CLK_ID,
+	RPI_FIRMWARE_H264_CLK_ID,
+	RPI_FIRMWARE_ISP_CLK_ID,
+	RPI_FIRMWARE_SDRAM_CLK_ID,
+	RPI_FIRMWARE_PIXEL_CLK_ID,
+	RPI_FIRMWARE_PWM_CLK_ID,
+	RPI_FIRMWARE_HEVC_CLK_ID,
+	RPI_FIRMWARE_EMMC2_CLK_ID,
+	RPI_FIRMWARE_M2MC_CLK_ID,
+	RPI_FIRMWARE_PIXEL_BVB_CLK_ID,
+	RPI_FIRMWARE_NUM_CLK_ID,
+};
+
+static char *rpi_firmware_clk_names[] = {
+	[RPI_FIRMWARE_EMMC_CLK_ID]	= "emmc",
+	[RPI_FIRMWARE_UART_CLK_ID]	= "uart",
+	[RPI_FIRMWARE_ARM_CLK_ID]	= "arm",
+	[RPI_FIRMWARE_CORE_CLK_ID]	= "core",
+	[RPI_FIRMWARE_V3D_CLK_ID]	= "v3d",
+	[RPI_FIRMWARE_H264_CLK_ID]	= "h264",
+	[RPI_FIRMWARE_ISP_CLK_ID]	= "isp",
+	[RPI_FIRMWARE_SDRAM_CLK_ID]	= "sdram",
+	[RPI_FIRMWARE_PIXEL_CLK_ID]	= "pixel",
+	[RPI_FIRMWARE_PWM_CLK_ID]	= "pwm",
+	[RPI_FIRMWARE_HEVC_CLK_ID]	= "hevc",
+	[RPI_FIRMWARE_EMMC2_CLK_ID]	= "emmc2",
+	[RPI_FIRMWARE_M2MC_CLK_ID]	= "m2mc",
+	[RPI_FIRMWARE_PIXEL_BVB_CLK_ID]	= "pixel-bvb",
+};
+
+#define RPI_FIRMWARE_STATE_ENABLE_BIT	BIT(0)
+#define RPI_FIRMWARE_STATE_WAIT_BIT	BIT(1)
+
+struct raspberrypi_clk {
+	struct device *dev;
+	struct rpi_firmware *firmware;
+	struct platform_device *cpufreq;
+};
+
+struct raspberrypi_clk_data {
+	struct clk_hw hw;
+
+	unsigned int id;
+
+	struct raspberrypi_clk *rpi;
+};
+
+/*
+ * Structure of the message passed to Raspberry Pi's firmware in order to
+ * change clock rates. The 'disable_turbo' option is only available to the ARM
+ * clock (pllb) which we enable by default as turbo mode will alter multiple
+ * clocks at once.
+ *
+ * Even though we're able to access the clock registers directly we're bound to
+ * use the firmware interface as the firmware ultimately takes care of
+ * mitigating overheating/undervoltage situations and we would be changing
+ * frequencies behind his back.
+ *
+ * For more information on the firmware interface check:
+ * https://github.com/raspberrypi/firmware/wiki/Mailbox-property-interface
+ */
+struct raspberrypi_firmware_prop {
+	__le32 id;
+	__le32 val;
+	__le32 disable_turbo;
+} __packed;
+
+static int raspberrypi_clock_property(struct rpi_firmware *firmware,
+				      const struct raspberrypi_clk_data *data,
+				      u32 tag, u32 *val)
+{
+	struct raspberrypi_firmware_prop msg = {
+		.id = cpu_to_le32(data->id),
+		.val = cpu_to_le32(*val),
+		.disable_turbo = cpu_to_le32(1),
+	};
+	int ret;
+
+	ret = rpi_firmware_property(firmware, tag, &msg, sizeof(msg));
+	if (ret)
+		return ret;
+
+	*val = le32_to_cpu(msg.val);
+
+	return 0;
+}
+
+static int raspberrypi_fw_is_prepared(struct clk_hw *hw)
+{
+	struct raspberrypi_clk_data *data =
+		container_of(hw, struct raspberrypi_clk_data, hw);
+	struct raspberrypi_clk *rpi = data->rpi;
+	u32 val = 0;
+	int ret;
+
+	ret = raspberrypi_clock_property(rpi->firmware, data,
+					 RPI_FIRMWARE_GET_CLOCK_STATE, &val);
+	if (ret)
+		return 0;
+
+	return !!(val & RPI_FIRMWARE_STATE_ENABLE_BIT);
+}
+
+
+static unsigned long raspberrypi_fw_get_rate(struct clk_hw *hw,
+					     unsigned long parent_rate)
+{
+	struct raspberrypi_clk_data *data =
+		container_of(hw, struct raspberrypi_clk_data, hw);
+	struct raspberrypi_clk *rpi = data->rpi;
+	u32 val = 0;
+	int ret;
+
+	ret = raspberrypi_clock_property(rpi->firmware, data,
+					 RPI_FIRMWARE_GET_CLOCK_RATE, &val);
+	if (ret)
+		return 0;
+
+	return val;
+}
+
+static int raspberrypi_fw_set_rate(struct clk_hw *hw, unsigned long rate,
+				   unsigned long parent_rate)
+{
+	struct raspberrypi_clk_data *data =
+		container_of(hw, struct raspberrypi_clk_data, hw);
+	struct raspberrypi_clk *rpi = data->rpi;
+	u32 _rate = rate;
+	int ret;
+
+	ret = raspberrypi_clock_property(rpi->firmware, data,
+					 RPI_FIRMWARE_SET_CLOCK_RATE, &_rate);
+	if (ret)
+		dev_err_ratelimited(rpi->dev, "Failed to change %s frequency: %d\n",
+				    clk_hw_get_name(hw), ret);
+
+	return ret;
+}
+
+static int raspberrypi_fw_dumb_determine_rate(struct clk_hw *hw,
+					      struct clk_rate_request *req)
+{
+	/*
+	 * The firmware will do the rounding but that isn't part of
+	 * the interface with the firmware, so we just do our best
+	 * here.
+	 */
+	req->rate = clamp(req->rate, req->min_rate, req->max_rate);
+	return 0;
+}
+
+static const struct clk_ops raspberrypi_firmware_clk_ops = {
+	.is_prepared	= raspberrypi_fw_is_prepared,
+	.recalc_rate	= raspberrypi_fw_get_rate,
+	.determine_rate	= raspberrypi_fw_dumb_determine_rate,
+	.set_rate	= raspberrypi_fw_set_rate,
+};
+
+static struct clk_hw *raspberrypi_clk_register(struct raspberrypi_clk *rpi,
+					       unsigned int parent,
+					       unsigned int id)
+{
+	struct raspberrypi_clk_data *data;
+	struct clk_init_data init = {};
+	u32 min_rate, max_rate;
+	int ret;
+
+	data = devm_kzalloc(rpi->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return ERR_PTR(-ENOMEM);
+	data->rpi = rpi;
+	data->id = id;
+
+	init.name = devm_kasprintf(rpi->dev, GFP_KERNEL,
+				   "fw-clk-%s",
+				   rpi_firmware_clk_names[id]);
+	init.ops = &raspberrypi_firmware_clk_ops;
+	init.flags = CLK_GET_RATE_NOCACHE;
+
+	data->hw.init = &init;
+
+	ret = raspberrypi_clock_property(rpi->firmware, data,
+					 RPI_FIRMWARE_GET_MIN_CLOCK_RATE,
+					 &min_rate);
+	if (ret) {
+		dev_err(rpi->dev, "Failed to get clock %d min freq: %d\n",
+			id, ret);
+		return ERR_PTR(ret);
+	}
+
+	ret = raspberrypi_clock_property(rpi->firmware, data,
+					 RPI_FIRMWARE_GET_MAX_CLOCK_RATE,
+					 &max_rate);
+	if (ret) {
+		dev_err(rpi->dev, "Failed to get clock %d max freq: %d\n",
+			id, ret);
+		return ERR_PTR(ret);
+	}
+
+	ret = devm_clk_hw_register(rpi->dev, &data->hw);
+	if (ret)
+		return ERR_PTR(ret);
+
+	clk_hw_set_rate_range(&data->hw, min_rate, max_rate);
+
+	if (id == RPI_FIRMWARE_ARM_CLK_ID) {
+		ret = devm_clk_hw_register_clkdev(rpi->dev, &data->hw,
+						  NULL, "cpu0");
+		if (ret) {
+			dev_err(rpi->dev, "Failed to initialize clkdev\n");
+			return ERR_PTR(ret);
+		}
+	}
+
+	return &data->hw;
+}
+
+struct rpi_firmware_get_clocks_response {
+	u32 parent;
+	u32 id;
+};
+
+static int raspberrypi_discover_clocks(struct raspberrypi_clk *rpi,
+				       struct clk_hw_onecell_data *data)
+{
+	struct rpi_firmware_get_clocks_response *clks;
+	int ret;
+
+	/*
+	 * The firmware doesn't guarantee that the last element of
+	 * RPI_FIRMWARE_GET_CLOCKS is zeroed. So allocate an additional
+	 * zero element as sentinel.
+	 */
+	clks = devm_kcalloc(rpi->dev,
+			    RPI_FIRMWARE_NUM_CLK_ID + 1, sizeof(*clks),
+			    GFP_KERNEL);
+	if (!clks)
+		return -ENOMEM;
+
+	ret = rpi_firmware_property(rpi->firmware, RPI_FIRMWARE_GET_CLOCKS,
+				    clks,
+				    sizeof(*clks) * RPI_FIRMWARE_NUM_CLK_ID);
+	if (ret)
+		return ret;
+
+	while (clks->id) {
+		struct clk_hw *hw;
+
+		switch (clks->id) {
+		case RPI_FIRMWARE_ARM_CLK_ID:
+		case RPI_FIRMWARE_CORE_CLK_ID:
+		case RPI_FIRMWARE_M2MC_CLK_ID:
+		case RPI_FIRMWARE_V3D_CLK_ID:
+		case RPI_FIRMWARE_PIXEL_BVB_CLK_ID:
+			hw = raspberrypi_clk_register(rpi, clks->parent,
+						      clks->id);
+			if (IS_ERR(hw))
+				return PTR_ERR(hw);
+
+			data->hws[clks->id] = hw;
+			data->num = clks->id + 1;
+			fallthrough;
+
+		default:
+			clks++;
+			break;
+		}
+	}
+
+	return 0;
+}
+
+static int raspberrypi_clk_probe(struct platform_device *pdev)
+{
+	struct clk_hw_onecell_data *clk_data;
+	struct device_node *firmware_node;
+	struct device *dev = &pdev->dev;
+	struct rpi_firmware *firmware;
+	struct raspberrypi_clk *rpi;
+	int ret;
+
+	/*
+	 * We can be probed either through the an old-fashioned
+	 * platform device registration or through a DT node that is a
+	 * child of the firmware node. Handle both cases.
+	 */
+	if (dev->of_node)
+		firmware_node = of_get_parent(dev->of_node);
+	else
+		firmware_node = of_find_compatible_node(NULL, NULL,
+							"raspberrypi,bcm2835-firmware");
+	if (!firmware_node) {
+		dev_err(dev, "Missing firmware node\n");
+		return -ENOENT;
+	}
+
+	firmware = rpi_firmware_get(firmware_node);
+	of_node_put(firmware_node);
+	if (!firmware)
+		return -EPROBE_DEFER;
+
+	rpi = devm_kzalloc(dev, sizeof(*rpi), GFP_KERNEL);
+	if (!rpi)
+		return -ENOMEM;
+
+	rpi->dev = dev;
+	rpi->firmware = firmware;
+	platform_set_drvdata(pdev, rpi);
+
+	clk_data = devm_kzalloc(dev, struct_size(clk_data, hws,
+						 RPI_FIRMWARE_NUM_CLK_ID),
+				GFP_KERNEL);
+	if (!clk_data)
+		return -ENOMEM;
+
+	ret = raspberrypi_discover_clocks(rpi, clk_data);
+	if (ret)
+		return ret;
+
+	ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
+					  clk_data);
+	if (ret)
+		return ret;
+
+	rpi->cpufreq = platform_device_register_data(dev, "raspberrypi-cpufreq",
+						     -1, NULL, 0);
+
+	return 0;
+}
+
+static int raspberrypi_clk_remove(struct platform_device *pdev)
+{
+	struct raspberrypi_clk *rpi = platform_get_drvdata(pdev);
+
+	platform_device_unregister(rpi->cpufreq);
+
+	return 0;
+}
+
+static const struct of_device_id raspberrypi_clk_match[] = {
+	{ .compatible = "raspberrypi,firmware-clocks" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, raspberrypi_clk_match);
+
+static struct platform_driver raspberrypi_clk_driver = {
+	.driver = {
+		.name = "raspberrypi-clk",
+		.of_match_table = raspberrypi_clk_match,
+	},
+	.probe          = raspberrypi_clk_probe,
+	.remove		= raspberrypi_clk_remove,
+};
+module_platform_driver(raspberrypi_clk_driver);
+
+MODULE_AUTHOR("Nicolas Saenz Julienne <nsaenzjulienne@suse.de>");
+MODULE_DESCRIPTION("Raspberry Pi firmware clock driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:raspberrypi-clk");