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SubjectRe: [PATCH 2/2] clk: add artpec-6 pll1 clock driver
Date
Hi Lars,

Quoting Lars Persson (2016-02-11 08:01:04)
> The PLL1 clock is a fixed-factor clock with factors derived from boot
> mode pins. This driver is a simple wrapper to register the fixed
> factor clock according to the pin settings.
>
> Signed-off-by: Lars Persson <larper@axis.com>
> ---
> drivers/clk/Makefile | 1 +
> drivers/clk/clk-artpec6.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 71 insertions(+)
> create mode 100644 drivers/clk/clk-artpec6.c
>
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index b038e36..388f0cf 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -17,6 +17,7 @@ endif
>
> # hardware specific clock types
> # please keep this section sorted lexicographically by file/directory path name
> +obj-$(CONFIG_MACH_ARTPEC6) += clk-artpec6.o
> obj-$(CONFIG_MACH_ASM9260) += clk-asm9260.o
> obj-$(CONFIG_COMMON_CLK_AXI_CLKGEN) += clk-axi-clkgen.o
> obj-$(CONFIG_ARCH_AXXIA) += clk-axm5516.o
> diff --git a/drivers/clk/clk-artpec6.c b/drivers/clk/clk-artpec6.c
> new file mode 100644
> index 0000000..3664c44
> --- /dev/null
> +++ b/drivers/clk/clk-artpec6.c

You mentioned having three drivers. Maybe consider putting this in
drivers/clk/axis?

Continuing my questions from patch #1, should this clock be coupled with
other artpec6 clocks sharing the same clock controller?

> @@ -0,0 +1,70 @@
> +/*
> + * ARTPEC-6 clock initialization
> + *
> + * Copyright 2015 Axis Comunications AB.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/clk-provider.h>
> +#include <linux/clkdev.h>
> +#include <linux/io.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +
> +static void __init of_artpec6_pll1_setup(struct device_node *np)
> +{
> + void __iomem *devstat;
> + struct clk *clk;
> + const char *clk_name = np->name;
> + const char *parent_name;
> + u32 pll_mode, pll_m, pll_n;
> +
> + parent_name = of_clk_get_parent_name(np, 0);
> +
> + devstat = of_iomap(np, 0);
> + if (devstat == NULL) {
> + pr_err("error to ioremap DEVSTAT\n");
> + return;
> + }
> +
> + /* DEVSTAT register contains PLL settings */
> + pll_mode = (readl(devstat) >> 6) & 3;
> + iounmap(devstat);
> +
> + /*
> + * pll1 settings are designed for different DDR speeds using a fixed
> + * 50MHz external clock. However, a different external clock could be
> + * used on different boards.
> + * CPU clock is half the DDR clock.
> + */
> + switch (pll_mode) {
> + case 0: /* DDR3-2133 mode */
> + pll_m = 4;
> + pll_n = 85;
> + break;
> + case 1: /* DDR3-1866 mode */
> + pll_m = 6;
> + pll_n = 112;
> + break;
> + case 2: /* DDR3-1600 mode */
> + pll_m = 4;
> + pll_n = 64;
> + break;
> + case 3: /* DDR3-1333 mode */
> + pll_m = 8;
> + pll_n = 106;
> + break;
> + }
> + /* ext_clk is defined in device tree */
> + clk = clk_register_fixed_factor(NULL, clk_name, parent_name, 0,
> + pll_n, pll_m);
> + if (IS_ERR(clk)) {
> + pr_err("%s not registered\n", clk_name);
> + return;
> + }
> + of_clk_add_provider(np, of_clk_src_simple_get, clk);
> +}
> +CLK_OF_DECLARE(artpec6_pll1, "axis,artpec6-pll1-clock", of_artpec6_pll1_setup);

Instead of using CLK_OF_DECLARE can you make this a platform_driver?

Best regards,
Mike

> --
> 2.1.4
>

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