bcm27xx: import latest patches from the RPi foundation

bcm2708: boot tested on RPi B+ v1.2
bcm2709: boot tested on RPi 3B v1.2 and RPi 4B v1.1 4G
bcm2710: boot tested on RPi 3B v1.2
bcm2711: boot tested on RPi 4B v1.1 4G

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

1 files changed, 173 insertions, 0 deletions

diff --git a/target/linux/bcm27xx/patches-5.4/950-0525-clk-bcm-rpi-Discover-the-firmware-clocks.patch b/target/linux/bcm27xx/patches-5.4/950-0525-clk-bcm-rpi-Discover-the-firmware-clocks.patch
new file mode 100644
index 0000000000..eaa4a81141
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.4/950-0525-clk-bcm-rpi-Discover-the-firmware-clocks.patch
@@ -0,0 +1,173 @@
+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);