Re: [PATCH 10/12] clk: samsung: Add Exynos850 clock driver stub
From: Andy Shevchenko <hidden>
Date: 2021-07-30 15:12:45
Also in:
linux-arm-kernel, linux-clk, linux-gpio, linux-samsung-soc, linux-serial, lkml
On Fri, Jul 30, 2021 at 5:51 PM Sam Protsenko [off-list ref] wrote:
For now it's just a stub driver to make serial driver work. Later it
make the serial
will be implemented properly. This driver doesn't really change clocks, only registers the UART clock as a fixed-rate clock. Without this clock driver the UART driver won't work, as it's trying to obtain "uart" clock and fails if it's not able to.
From drivers/tty/serial/samsung_tty.c:
8<------------------------------------------------------------------->8
ourport->clk = clk_get(&platdev->dev, "uart");
if (IS_ERR(ourport->clk)) {
pr_err("%s: Controller clock not found\n",
dev_name(&platdev->dev));
ret = PTR_ERR(ourport->clk);
goto err;
}
8<------------------------------------------------------------------->8This is not needed in the commit message.
In order to get functional serial console we have to implement that
get a functional
minimal clock driver with "uart" clock. It's not necessary to actually configure clocks, as those are already configured in bootloader, so kernel can rely on that for now.
80 column limit is broken here to make checkpatch happy, otherwise it swears about incorrect __initconst usage.
Again, no need to be in the commit message, use the comment field for this (after the cutter '---' line below).
quoted hunk ↗ jump to hunk
Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org> --- drivers/clk/samsung/Makefile | 1 + drivers/clk/samsung/clk-exynos850.c | 63 +++++++++++++++++++++++++++++ 2 files changed, 64 insertions(+) create mode 100644 drivers/clk/samsung/clk-exynos850.cdiff --git a/drivers/clk/samsung/Makefile b/drivers/clk/samsung/Makefile index 028b2e27a37e..c46cf11e4d0b 100644 --- a/drivers/clk/samsung/Makefile +++ b/drivers/clk/samsung/Makefile@@ -17,6 +17,7 @@ obj-$(CONFIG_EXYNOS_ARM64_COMMON_CLK) += clk-exynos5433.o obj-$(CONFIG_EXYNOS_AUDSS_CLK_CON) += clk-exynos-audss.o obj-$(CONFIG_EXYNOS_CLKOUT) += clk-exynos-clkout.o obj-$(CONFIG_EXYNOS_ARM64_COMMON_CLK) += clk-exynos7.o +obj-$(CONFIG_EXYNOS_ARM64_COMMON_CLK) += clk-exynos850.o obj-$(CONFIG_S3C2410_COMMON_CLK)+= clk-s3c2410.o obj-$(CONFIG_S3C2410_COMMON_DCLK)+= clk-s3c2410-dclk.o obj-$(CONFIG_S3C2412_COMMON_CLK)+= clk-s3c2412.odiff --git a/drivers/clk/samsung/clk-exynos850.c b/drivers/clk/samsung/clk-exynos850.c new file mode 100644 index 000000000000..3192ec9bb90b --- /dev/null +++ b/drivers/clk/samsung/clk-exynos850.c@@ -0,0 +1,63 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2019 Samsung Electronics Co., Ltd. + * Copyright (C) 2021 Linaro Ltd. + * + * Common Clock Framework support for Exynos850 SoC. + */ + +#include <linux/clk.h> +#include <linux/clkdev.h> +#include <linux/clk-provider.h> +#include <linux/of.h> +#include <linux/of_address.h>
+ blank line?
+#include <dt-bindings/clock/exynos850.h>
+
+#include "clk.h"
+
+/* Fixed rate clocks generated outside the SoC */
+static struct samsung_fixed_rate_clock exynos850_fixed_rate_ext_clks[] __initdata = {
+ FRATE(OSCCLK, "fin_pll", NULL, 0, 26000000),
+};
+
+/*
+ * Model the UART clock as a fixed-rate clock for now, to make serial driver
+ * work. This clock is already configured in the bootloader.
+ */
+static const struct samsung_fixed_rate_clock exynos850_peri_clks[] __initconst = {
+ FRATE(DOUT_UART, "DOUT_UART", NULL, 0, 200000000),
+};
+
+static const struct of_device_id ext_clk_match[] __initconst = {+ { .compatible = "samsung,exynos850-oscclk", .data = (void *)0 },0 is the default for static variables.
+ {},No comma needed for the terminator lines.
+};
+
+void __init exynos850_clk_init(struct device_node *np)
+{
+ void __iomem *reg_base;
+ struct samsung_clk_provider *ctx;+ if (!np)
+ panic("%s: unable to determine soc\n", __func__);Check for the sake of additional code?
+ reg_base = of_iomap(np, 0);
This will fail when np == NULL.
+ if (!reg_base)
+ panic("%s: failed to map registers\n", __func__);
+
+ ctx = samsung_clk_init(np, reg_base, CLK_NR_CLKS);
+ if (!ctx)
+ panic("%s: unable to allocate ctx\n", __func__);
+
+ samsung_clk_of_register_fixed_ext(ctx,
+ exynos850_fixed_rate_ext_clks,
+ ARRAY_SIZE(exynos850_fixed_rate_ext_clks),
+ ext_clk_match);
+
+ samsung_clk_register_fixed_rate(ctx, exynos850_peri_clks,
+ ARRAY_SIZE(exynos850_peri_clks));
+
+ samsung_clk_of_add_provider(np, ctx);
+}
+
+CLK_OF_DECLARE(exynos850_clk, "samsung,exynos850-clock", exynos850_clk_init);-- With Best Regards, Andy Shevchenko