openwrt/target/linux/bcm27xx/patches-5.4/950-0032-amba_pl011-Round-input-clock-up.patch
Hauke Mehrtens c6ddf8d502 kernel: bump 5.4 to 5.4.179
Many changes were done in drivers/pinctrl/bcm/pinctrl-bcm2835.c between
5.4.171 and 5.4.179.
The following 3 patches do not apply any more:
* target/linux/bcm27xx/patches-5.4/950-0316-pinctrl-bcm2835-Add-support-for-BCM2711-pull-up-func.patch
  This was already integrated in kernel v5.4-rc1, it was never needed.

* target/linux/bcm27xx/patches-5.4/950-0328-Revert-pinctrl-bcm2835-Pass-irqchip-when-adding-gpio.patch
* target/linux/bcm27xx/patches-5.4/950-0362-pinctrl-bcm2835-Change-init-order-for-gpio-hogs.patch
I think these were done to fix the problem which was really fixed in
commit 75278f1aff5e ("pinctrl: bcm2835: Change init order for gpio
hogs") from v5.4.175

target/linux/generic/backport-5.4/716-v5.5-net-sfp-move-fwnode-parsing-into-sfp-bus-layer.patch
Move fwnode_device_is_available to the same position as in kernel 5.10.

target/linux/layerscape/patches-5.4/302-dts-0083-arm64-ls1028a-qds-correct-bus-of-rtc.patch
Applied in commit 65816c1034769e714edb70f59a33bc5472d9e55f ("arm64: dts:
ls1028a-qds: move rtc node to the correct i2c bus")

Compile-tested: lantiq/xrx200, bcm27xx/bcm2710
Run-tested: lantiq/xrx200

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
2022-02-12 19:41:39 +01:00

87 lines
2.5 KiB
Diff

From 409f4b56de7611d703790c54a70fad9a6e2bb161 Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.org>
Date: Wed, 1 Mar 2017 16:07:39 +0000
Subject: [PATCH] amba_pl011: Round input clock up
The UART clock is initialised to be as close to the requested
frequency as possible without exceeding it. Now that there is a
clock manager that returns the actual frequencies, an expected
48MHz clock is reported as 47999625. If the requested baudrate
== requested clock/16, there is no headroom and the slight
reduction in actual clock rate results in failure.
Detect cases where it looks like a "round" clock was chosen and
adjust the reported clock to match that "round" value. As the
code comment says:
/*
* If increasing a clock by less than 0.1% changes it
* from ..999.. to ..000.., round up.
*/
Signed-off-by: Phil Elwell <phil@raspberrypi.org>
---
drivers/tty/serial/amba-pl011.c | 23 +++++++++++++++++++++--
1 file changed, 21 insertions(+), 2 deletions(-)
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -1653,6 +1653,23 @@ static void pl011_put_poll_char(struct u
#endif /* CONFIG_CONSOLE_POLL */
+unsigned long pl011_clk_round(unsigned long clk)
+{
+ unsigned long scaler;
+
+ /*
+ * If increasing a clock by less than 0.1% changes it
+ * from ..999.. to ..000.., round up.
+ */
+ scaler = 1;
+ while (scaler * 100000 < clk)
+ scaler *= 10;
+ if ((clk + scaler - 1)/scaler % 1000 == 0)
+ clk = (clk/scaler + 1) * scaler;
+
+ return clk;
+}
+
static int pl011_hwinit(struct uart_port *port)
{
struct uart_amba_port *uap =
@@ -1669,7 +1686,7 @@ static int pl011_hwinit(struct uart_port
if (retval)
return retval;
- uap->port.uartclk = clk_get_rate(uap->clk);
+ uap->port.uartclk = pl011_clk_round(clk_get_rate(uap->clk));
/* Clear pending error and receive interrupts */
pl011_write(UART011_OEIS | UART011_BEIS | UART011_PEIS |
@@ -2303,7 +2320,7 @@ static int pl011_console_setup(struct co
plat->init();
}
- uap->port.uartclk = clk_get_rate(uap->clk);
+ uap->port.uartclk = pl011_clk_round(clk_get_rate(uap->clk));
if (uap->vendor->fixed_options) {
baud = uap->fixed_baud;
@@ -2488,6 +2505,7 @@ static struct uart_driver amba_reg = {
.cons = AMBA_CONSOLE,
};
+#if 0
static int pl011_probe_dt_alias(int index, struct device *dev)
{
struct device_node *np;
@@ -2519,6 +2537,7 @@ static int pl011_probe_dt_alias(int inde
return ret;
}
+#endif
/* unregisters the driver also if no more ports are left */
static void pl011_unregister_port(struct uart_amba_port *uap)