--- /dev/null
+From 54276fe20c0735dd18d298891b71b664ea54962d Mon Sep 17 00:00:00 2001
+From: Maxime Ripard <maxime@cerno.tech>
+Date: Mon, 10 Feb 2020 14:06:09 +0100
+Subject: [PATCH] clk: bcm: rpi: Discover the firmware clocks
+
+The RaspberryPi4 firmware actually exposes more clocks than are currently
+handled by the driver and we will need to change some of them directly
+based on the pixel rate for the display related clocks, or the load for the
+GPU.
+
+This rate change can have a number of side-effects, including adjusting the
+various PLL voltages or the PLL parents. The firmware will also update
+those clocks by itself for example if the SoC runs too hot.
+
+In order to make Linux play as nice as possible with those constraints, it
+makes sense to rely on the firmware clocks as much as possible.
+
+Fortunately,t he firmware has an interface to discover the clocks it
+exposes.
+
+Let's use it to discover, register the clocks in the clocks framework and
+then expose them through the device tree for consumers to use them.
+
+Cc: Michael Turquette <mturquette@baylibre.com>
+Cc: Stephen Boyd <sboyd@kernel.org>
+Cc: linux-clk@vger.kernel.org
+Signed-off-by: Maxime Ripard <maxime@cerno.tech>
+---
+ drivers/clk/bcm/clk-raspberrypi.c | 104 ++++++++++++++++++---
+ include/soc/bcm2835/raspberrypi-firmware.h | 5 +
+ 2 files changed, 97 insertions(+), 12 deletions(-)
+
+--- a/drivers/clk/bcm/clk-raspberrypi.c
++++ b/drivers/clk/bcm/clk-raspberrypi.c
+@@ -285,6 +285,95 @@ static struct clk_hw *raspberrypi_regist
+ return &raspberrypi_clk_pllb_arm.hw;
+ }
+
++static long raspberrypi_fw_dumb_round_rate(struct clk_hw *hw,
++ unsigned long rate,
++ unsigned long *parent_rate)
++{
++ /*
++ * The firmware will do the rounding but that isn't part of
++ * the interface with the firmware, so we just do our best
++ * here.
++ */
++ return rate;
++}
++
++static const struct clk_ops raspberrypi_firmware_clk_ops = {
++ .is_prepared = raspberrypi_fw_is_prepared,
++ .recalc_rate = raspberrypi_fw_get_rate,
++ .round_rate = raspberrypi_fw_dumb_round_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 = {};
++ int ret;
++
++ if (id == RPI_FIRMWARE_ARM_CLK_ID) {
++ struct clk_hw *hw;
++
++ hw = raspberrypi_register_pllb(rpi);
++ if (IS_ERR(hw)) {
++ dev_err(rpi->dev, "Failed to initialize pllb, %ld\n",
++ PTR_ERR(hw));
++ return hw;
++ }
++
++ return raspberrypi_register_pllb_arm(rpi);
++ }
++
++ 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-%u", id);
++ init.ops = &raspberrypi_firmware_clk_ops;
++ init.flags = CLK_GET_RATE_NOCACHE;
++
++ data->hw.init = &init;
++
++ ret = devm_clk_hw_register(rpi->dev, &data->hw);
++ if (ret)
++ return ERR_PTR(ret);
++
++ return &data->hw;
++}
++
++static int raspberrypi_discover_clocks(struct raspberrypi_clk *rpi,
++ struct clk_hw_onecell_data *data)
++{
++ struct rpi_firmware_get_clocks_response *clks;
++ int ret;
++
++ clks = devm_kcalloc(rpi->dev, sizeof(*clks), NUM_FW_CLKS, GFP_KERNEL);
++ if (!clks)
++ return -ENOMEM;
++
++ ret = rpi_firmware_property(rpi->firmware, RPI_FIRMWARE_GET_CLOCKS,
++ clks, sizeof(*clks) * NUM_FW_CLKS);
++ if (ret)
++ return ret;
++
++ while (clks->id) {
++ struct clk_hw *hw;
++
++ 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;
++ clks++;
++ }
++
++ return 0;
++}
++
+ static int raspberrypi_clk_probe(struct platform_device *pdev)
+ {
+ struct clk_hw_onecell_data *clk_data;
+@@ -292,7 +381,6 @@ static int raspberrypi_clk_probe(struct
+ struct device *dev = &pdev->dev;
+ struct rpi_firmware *firmware;
+ struct raspberrypi_clk *rpi;
+- struct clk_hw *hw;
+ int ret;
+
+ firmware_node = of_parse_phandle(dev->of_node, "raspberrypi,firmware", 0);
+@@ -318,17 +406,9 @@ static int raspberrypi_clk_probe(struct
+ if (!clk_data)
+ return -ENOMEM;
+
+- hw = raspberrypi_register_pllb(rpi);
+- if (IS_ERR(hw)) {
+- dev_err(dev, "Failed to initialize pllb, %ld\n", PTR_ERR(hw));
+- return PTR_ERR(hw);
+- }
+-
+- hw = raspberrypi_register_pllb_arm(rpi);
+- if (IS_ERR(hw))
+- return PTR_ERR(hw);
+- clk_data->hws[RPI_FIRMWARE_ARM_CLK_ID] = hw;
+- clk_data->num = RPI_FIRMWARE_ARM_CLK_ID + 1;
++ 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);
+--- a/include/soc/bcm2835/raspberrypi-firmware.h
++++ b/include/soc/bcm2835/raspberrypi-firmware.h
+@@ -160,6 +160,11 @@ enum rpi_firmware_property_tag {
+
+ #define GET_DISPLAY_SETTINGS_PAYLOAD_SIZE 64
+
++struct rpi_firmware_get_clocks_response {
++ __le32 parent;
++ __le32 id;
++};
++
+ #if IS_ENABLED(CONFIG_RASPBERRYPI_FIRMWARE)
+ int rpi_firmware_property(struct rpi_firmware *fw,
+ u32 tag, void *data, size_t len);
projects / openwrt / staging / luka.git / blobdiff