Re: [PATCH 2/2] clk: rockchip: Add support for the mmc clock phases using the framework
From: Heiko Stübner
Date: Fri Nov 14 2014 - 18:39:56 EST
Hi,
Am Freitag, 14. November 2014, 14:52:54 schrieb Alexandru M Stan:
> The drive and sample phases are generated by dividing an upstream parent
> clock by 2, this allows us to adjust the phase by 90 deg.
>
> There's also an option to have up to 255 delay elements (40-80 picoseconds
> long). This driver uses those elements (under the assumption that they're
> 60ps long) to generate a rough 45deg (which might be from 33deg to 66deg)
> setting.
>
> Suggested-by: Heiko Stuebner <heiko@xxxxxxxxx>
> Signed-off-by: Alexandru M Stan <amstan@xxxxxxxxxxxx>
apart from the dangling #define DEBUG below, this looks good to me.
But I'd like to get a go ahead from Mike for this bigger chunk of new code.
> ---
> drivers/clk/rockchip/Makefile | 1 +
> drivers/clk/rockchip/clk-mmc-phase.c | 150
> +++++++++++++++++++++++++++++++++++ drivers/clk/rockchip/clk-rk3288.c |
> 12 +++
> drivers/clk/rockchip/clk.c | 8 ++
> drivers/clk/rockchip/clk.h | 23 ++++++
> 5 files changed, 194 insertions(+)
> create mode 100644 drivers/clk/rockchip/clk-mmc-phase.c
>
> diff --git a/drivers/clk/rockchip/Makefile b/drivers/clk/rockchip/Makefile
> index bd8514d..2714097 100644
> --- a/drivers/clk/rockchip/Makefile
> +++ b/drivers/clk/rockchip/Makefile
> @@ -6,6 +6,7 @@ obj-y += clk-rockchip.o
> obj-y += clk.o
> obj-y += clk-pll.o
> obj-y += clk-cpu.o
> +obj-y += clk-mmc-phase.o
> obj-$(CONFIG_RESET_CONTROLLER) += softrst.o
>
> obj-y += clk-rk3188.o
> diff --git a/drivers/clk/rockchip/clk-mmc-phase.c
> b/drivers/clk/rockchip/clk-mmc-phase.c new file mode 100644
> index 0000000..5c1532a
> --- /dev/null
> +++ b/drivers/clk/rockchip/clk-mmc-phase.c
> @@ -0,0 +1,150 @@
> +/*
> + * Copyright 2014 Google, Inc
> + * Author: Alexandru M Stan <amstan@xxxxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#define DEBUG
should not be here
Heiko
> +#include <linux/slab.h>
> +#include <linux/clk-provider.h>
> +#include "clk.h"
> +
> +struct rockchip_mmc_clock_phase {
> + struct clk_hw hw;
> + void __iomem *reg;
> + int id;
> + int shift;
> +};
> +
> +#define to_phase(_hw) container_of(_hw, struct rockchip_mmc_clock_phase,
> hw) +
> +static unsigned long rockchip_mmc_recalc(struct clk_hw *hw,
> + unsigned long parent_rate)
> +{
> + return parent_rate / 2;
> +}
> +
> +#define ROCKCHIP_MMC_DELAY_SEL BIT(10)
> +#define ROCKCHIP_MMC_DEGREE_MASK 0x3
> +#define ROCKCHIP_MMC_DELAYNUM_OFFSET 2
> +#define ROCKCHIP_MMC_DELAYNUM_MASK (0xff << ROCKCHIP_MMC_DELAYNUM_OFFSET)
> +
> +#define PSECS_PER_SEC 1000000000000LL
> +
> +/*
> + * Each fine delay is between 40ps-80ps. Assume each fine delay is 60ps to
> + * simplify calculations. So 45degs could be anywhere between 33deg and
> 66deg. + */
> +#define DELAY_ELEMENT_PSEC 60
> +
> +static int rockchip_mmc_get_phase(struct clk_hw *hw)
> +{
> + struct rockchip_mmc_clock_phase *phase = to_phase(hw);
> + unsigned long rate = clk_get_rate(hw->clk);
> + u32 raw_value;
> + u16 degrees;
> + u8 delay_num = 0;
> +
> + raw_value = readl(phase->reg) >> (phase->shift);
> +
> + degrees = (raw_value & ROCKCHIP_MMC_DEGREE_MASK) * 90;
> +
> + if (raw_value & ROCKCHIP_MMC_DELAY_SEL) {
> + /* degrees/delaynum * 10000 */
> + unsigned long factor = (DELAY_ELEMENT_PSEC / 10) * 36 *
> + (rate / 1000000);
> +
> + delay_num = (raw_value & ROCKCHIP_MMC_DELAYNUM_MASK);
> + delay_num >>= ROCKCHIP_MMC_DELAYNUM_OFFSET;
> + degrees += delay_num * factor / 10000;
> + }
> +
> + return degrees % 360;
> +}
> +
> +static int rockchip_mmc_set_phase(struct clk_hw *hw, int degrees)
> +{
> + struct rockchip_mmc_clock_phase *phase = to_phase(hw);
> + unsigned long rate = clk_get_rate(hw->clk);
> + u8 nineties, is_fortyfive;
> + u8 delay_num = 0;
> + u32 raw_value;
> +
> + degrees -= degrees % 45;
> +
> + nineties = degrees / 90;
> + is_fortyfive = (degrees % 90) == 45;
> +
> + if (is_fortyfive) {
> + u64 delay;
> +
> + delay = PSECS_PER_SEC;
> + do_div(delay, rate);
> + do_div(delay, 360 / 45);
> + do_div(delay, DELAY_ELEMENT_PSEC);
> +
> + delay_num = (u8) min(delay, 255ULL);
> + }
> +
> + raw_value = ROCKCHIP_MMC_DELAY_SEL;
> + raw_value |= delay_num << ROCKCHIP_MMC_DELAYNUM_OFFSET;
> + raw_value |= nineties;
> + writel(HIWORD_UPDATE(raw_value, 0xffff, phase->shift), phase->reg);
> +
> + pr_debug("%s->set_phase(%d) delay_nums=%u reg[0x%p]=0x%x
> actual_degrees=%d\n", + __clk_get_name(hw->clk), degrees, delay_num,
> + phase->reg, raw_value>>phase->shift,
> + rockchip_mmc_get_phase(hw)
> + );
> +
> + return 0;
> +}
> +
> +static const struct clk_ops rockchip_phase_clk_ops = {
> + .recalc_rate = rockchip_mmc_recalc,
> + .get_phase = rockchip_mmc_get_phase,
> + .set_phase = rockchip_mmc_set_phase,
> +};
> +
> +struct clk *rockchip_clk_register_mmc_phase(const char *name,
> + const char **parent_names, u8 num_parents,
> + void __iomem *reg, int shift)
> +{
> + struct clk_init_data init;
> + struct rockchip_mmc_clock_phase *phase;
> + struct clk *clk;
> +
> + phase = kmalloc(sizeof(*phase), GFP_KERNEL);
> + if (!phase)
> + return NULL;
> +
> + init.num_parents = num_parents;
> + init.parent_names = parent_names;
> + init.ops = &rockchip_phase_clk_ops;
> +
> + phase->hw.init = &init;
> + phase->reg = reg;
> + phase->shift = shift;
> +
> + if (name)
> + init.name = name;
> +
> + clk = clk_register(NULL, &phase->hw);
> + if (IS_ERR(clk))
> + goto err_free;
> +
> + return clk;
> +
> +err_free:
> + kfree(phase);
> + return NULL;
> +}
> diff --git a/drivers/clk/rockchip/clk-rk3288.c
> b/drivers/clk/rockchip/clk-rk3288.c index 2327829..273d28a 100644
> --- a/drivers/clk/rockchip/clk-rk3288.c
> +++ b/drivers/clk/rockchip/clk-rk3288.c
> @@ -483,6 +483,18 @@ static struct rockchip_clk_branch rk3288_clk_branches[]
> __initdata = { RK3288_CLKSEL_CON(12), 14, 2, MFLAGS, 8, 6, DFLAGS,
> RK3288_CLKGATE_CON(13), 3, GFLAGS),
>
> + MMC_PHASE(SCLK_SDMMC_DRV_PHASE, "sdmmc_drv", "sclk_sdmmc",
> RK3288_SDMMC_CON0, 1), + MMC_PHASE(SCLK_SDMMC_SAMPLE_PHASE, "sdmmc_sample",
> "sclk_sdmmc", RK3288_SDMMC_CON1, 0), +
> + MMC_PHASE(SCLK_SDIO0_DRV_PHASE, "sdio0_drv", "sclk_sdio0",
> RK3288_SDIO0_CON0, 1), + MMC_PHASE(SCLK_SDIO0_SAMPLE_PHASE, "sdio0_sample",
> "sclk_sdio0", RK3288_SDIO0_CON1, 0), +
> + MMC_PHASE(SCLK_SDIO1_DRV_PHASE, "sdio1_drv", "sclk_sdio1",
> RK3288_SDIO1_CON0, 1), + MMC_PHASE(SCLK_SDIO1_SAMPLE_PHASE, "sdio1_sample",
> "sclk_sdio1", RK3288_SDIO1_CON1, 0), +
> + MMC_PHASE(SCLK_EMMC_DRV_PHASE, "emmc_drv", "sclk_emmc",
> RK3288_EMMC_CON0, 1), + MMC_PHASE(SCLK_EMMC_SAMPLE_PHASE, "emmc_sample",
> "sclk_emmc", RK3288_EMMC_CON1, 0), +
> COMPOSITE(0, "sclk_tspout", mux_tspout_p, 0,
> RK3288_CLKSEL_CON(35), 14, 2, MFLAGS, 8, 5, DFLAGS,
> RK3288_CLKGATE_CON(4), 11, GFLAGS),
> diff --git a/drivers/clk/rockchip/clk.c b/drivers/clk/rockchip/clk.c
> index 1e68bff..3149905 100644
> --- a/drivers/clk/rockchip/clk.c
> +++ b/drivers/clk/rockchip/clk.c
> @@ -279,6 +279,14 @@ void __init rockchip_clk_register_branches(
> list->gate_offset, list->gate_shift,
> list->gate_flags, flags, &clk_lock);
> break;
> + case branch_mmc_phase:
> + clk = rockchip_clk_register_mmc_phase(
> + list->name,
> + list->parent_names, list->num_parents,
> + reg_base + list->muxdiv_offset,
> + list->div_shift
> + );
> + break;
> }
>
> /* none of the cases above matched */
> diff --git a/drivers/clk/rockchip/clk.h b/drivers/clk/rockchip/clk.h
> index ca009ab..9ff5e2e 100644
> --- a/drivers/clk/rockchip/clk.h
> +++ b/drivers/clk/rockchip/clk.h
> @@ -48,6 +48,14 @@
> #define RK3288_GLB_SRST_SND 0x1b4
> #define RK3288_SOFTRST_CON(x) (x * 0x4 + 0x1b8)
> #define RK3288_MISC_CON 0x1e8
> +#define RK3288_SDMMC_CON0 0x200
> +#define RK3288_SDMMC_CON1 0x204
> +#define RK3288_SDIO0_CON0 0x208
> +#define RK3288_SDIO0_CON1 0x20c
> +#define RK3288_SDIO1_CON0 0x210
> +#define RK3288_SDIO1_CON1 0x214
> +#define RK3288_EMMC_CON0 0x218
> +#define RK3288_EMMC_CON1 0x21c
>
> enum rockchip_pll_type {
> pll_rk3066,
> @@ -152,6 +160,10 @@ struct clk *rockchip_clk_register_cpuclk(const char
> *name, const struct rockchip_cpuclk_rate_table *rates,
> int nrates, void __iomem *reg_base, spinlock_t *lock);
>
> +struct clk *rockchip_clk_register_mmc_phase(const char *name,
> + const char **parent_names, u8 num_parents,
> + void __iomem *reg, int shift);
> +
> #define PNAME(x) static const char *x[] __initconst
>
> enum rockchip_clk_branch_type {
> @@ -160,6 +172,7 @@ enum rockchip_clk_branch_type {
> branch_divider,
> branch_fraction_divider,
> branch_gate,
> + branch_mmc_phase,
> };
>
> struct rockchip_clk_branch {
> @@ -352,6 +365,16 @@ struct rockchip_clk_branch {
> .gate_flags = gf, \
> }
>
> +#define MMC_PHASE(_id, cname, pname, offset, shift) \
> + { \
> + .id = _id, \
> + .branch_type = branch_mmc_phase, \
> + .name = cname, \
> + .parent_names = (const char *[]){ pname }, \
> + .num_parents = 1, \
> + .muxdiv_offset = offset, \
> + .div_shift = shift, \
> + }
>
> void rockchip_clk_init(struct device_node *np, void __iomem *base,
> unsigned long nr_clks);
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