openwrt/target/linux/bcm27xx/patches-5.4/950-0779-clk-bcm-rpi-Use-CCF-boundaries-instead-of-rolling-ou.patch

From cd72d75cfb216a7ef15ec8649e57b03b4fc48b62 Mon Sep 17 00:00:00 2001
From: Maxime Ripard <maxime@cerno.tech>
Date: Wed, 27 May 2020 11:13:52 +0200
Subject: [PATCH] clk: bcm: rpi: Use CCF boundaries instead of
 rolling our own

The raspberrypi firmware clock driver has a min_rate / max_rate clamping by
storing the info it needs in a private structure.

However, the CCF already provides such a facility, so we can switch to it
to remove the boilerplate.

Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
 drivers/clk/bcm/clk-raspberrypi.c | 49 ++++++++++++++++++++-----------
 1 file changed, 32 insertions(+), 17 deletions(-)

--- a/drivers/clk/bcm/clk-raspberrypi.c
+++ b/drivers/clk/bcm/clk-raspberrypi.c
@@ -57,9 +57,6 @@ struct raspberrypi_clk_data {
 	struct clk_hw hw;
 	unsigned id;
 
-	unsigned long min_rate;
-	unsigned long max_rate;
-
 	struct raspberrypi_clk *rpi;
 };
 
@@ -177,13 +174,11 @@ static int raspberrypi_fw_pll_set_rate(s
 static int raspberrypi_pll_determine_rate(struct clk_hw *hw,
 					  struct clk_rate_request *req)
 {
-	struct raspberrypi_clk_data *data =
-		container_of(hw, struct raspberrypi_clk_data, hw);
 	u64 div, final_rate;
 	u32 ndiv, fdiv;
 
 	/* We can't use req->rate directly as it would overflow */
-	final_rate = clamp(req->rate, data->min_rate, data->max_rate);
+	final_rate = clamp(req->rate, req->min_rate, req->max_rate);
 
 	div = (u64)final_rate << A2W_PLL_FRAC_BITS;
 	do_div(div, req->best_parent_rate);
@@ -254,16 +249,15 @@ static struct clk_hw *raspberrypi_regist
 	dev_info(rpi->dev, "CPU frequency range: min %u, max %u\n",
 		 min_rate, max_rate);
 
-	data->min_rate = min_rate * RPI_FIRMWARE_PLLB_ARM_DIV_RATE;
-	data->max_rate = max_rate * RPI_FIRMWARE_PLLB_ARM_DIV_RATE;
-
 	data->hw.init = &init;
 
 	ret = devm_clk_hw_register(rpi->dev, &data->hw);
-	if (ret)
-		return ERR_PTR(ret);
+	if (!ret)
+		clk_hw_set_rate_range(&data->hw,
+				      min_rate * RPI_FIRMWARE_PLLB_ARM_DIV_RATE,
+				      max_rate * RPI_FIRMWARE_PLLB_ARM_DIV_RATE);
 
-	return &data->hw;
+	return ret;
 }
 
 static struct clk_fixed_factor raspberrypi_clk_pllb_arm = {
@@ -299,22 +293,22 @@ 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)
+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.
 	 */
-	return rate;
+	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,
-	.round_rate	= raspberrypi_fw_dumb_round_rate,
+	.determine_rate	= raspberrypi_fw_dumb_determine_rate,
 	.set_rate	= raspberrypi_fw_set_rate,
 };
 
@@ -324,6 +318,7 @@ static struct clk_hw *raspberrypi_clk_re
 {
 	struct raspberrypi_clk_data *data;
 	struct clk_init_data init = {};
+	u32 min_rate, max_rate;
 	int ret;
 
 	if (id == RPI_FIRMWARE_ARM_CLK_ID) {
@@ -351,10 +346,30 @@ static struct clk_hw *raspberrypi_clk_re
 
 	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 %s min freq: %d\n",
+			init.name, 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 %s max freq: %d\n",
+			init.name, 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);
+
 	return &data->hw;
 }