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From: Rouven Czerwinski <r.czerwinski@pengutronix.de>
Date: Thu, 13 Dec 2018 07:23:37 +0100
Subject: [PATCH] ARM: rpi: retrieve miniuart clock from firmware
The miniuart uses the core clock as the clock source. This clock is fixed by the
firmware to 250Mhz if enable_uart=1 is set in the config.txt file.
However a user could still choose to overclock the core frequency,
which would result in wrong baudrates computed by barebox.
Retrieve the core clock frequency from the firmware to allow all potential
firmware configurations to work with barebox.
Signed-off-by: Rouven Czerwinski <r.czerwinski@pengutronix.de>
---
arch/arm/boards/raspberry-pi/rpi-common.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/arch/arm/boards/raspberry-pi/rpi-common.c b/arch/arm/boards/raspberry-pi/rpi-common.c
index 887f096f7e4e..f22239c7ccb6 100644
--- a/arch/arm/boards/raspberry-pi/rpi-common.c
+++ b/arch/arm/boards/raspberry-pi/rpi-common.c
@@ -310,6 +310,13 @@ static int rpi_console_clock_init(void)
clkdev_add_physbase(clk, 0x20201000, NULL);
clkdev_add_physbase(clk, 0x3f201000, NULL);
+ clk = rpi_register_firmware_clock(BCM2835_MBOX_CLOCK_ID_CORE,
+ "uart1-8250");
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+
+ clkdev_add_physbase(clk, 0x3f215040, NULL);
+
clk = clk_fixed("bcm2835-cs", 1 * 1000 * 1000);
clk_register_clkdev(clk, NULL, "bcm2835-cs");
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