On Tue, Oct 29, 2013 at 03:55:11PM +0100, Laurent Pinchart wrote:
> The R8A7790 has several clocks that are too custom to be supported in a
> generic driver. Those clocks can be divided in two categories:
>
> - Fixed rate clocks with multiplier and divisor set according to boot
> mode configuration
>
> - Custom divider clocks with SoC-specific divider values
>
> This driver supports both.
>
> Signed-off-by: Laurent Pinchart <[email protected]>
> ---
> .../bindings/clock/renesas,r8a7790-cpg-clocks.txt | 26 +++
> drivers/clk/shmobile/Makefile | 1 +
> drivers/clk/shmobile/clk-r8a7790.c | 176
> +++++++++++++++++++++
> include/dt-bindings/clock/r8a7790-clock.h | 10 ++
> include/linux/clk/shmobile.h | 19 +++
> 5 files changed, 232 insertions(+)
> create mode 100644
> Documentation/devicetree/bindings/clock/renesas,r8a7790-cpg-clocks.txt
> create mode 100644 drivers/clk/shmobile/clk-r8a7790.c
> create mode 100644 include/linux/clk/shmobile.h
>
> diff --git
> a/Documentation/devicetree/bindings/clock/renesas,r8a7790-cpg-clocks.txt
> b/Documentation/devicetree/bindings/clock/renesas,r8a7790-cpg-clocks.txt
> new file mode 100644
> index 0000000..d889917
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/renesas,r8a7790-cpg-clocks.txt
> @@ -0,0 +1,26 @@
> +* Renesas R8A7790 Clock Pulse Generator (CPG)
> +
> +The CPG generates core clocks for the R8A7790. It includes three PLLs and
> +several fixed ratio dividers.
> +
> +Required Properties:
> +
> + - compatible: Must be "renesas,r8a7790-cpg-clocks"
> + - reg: Base address and length of the memory resource used by the CPG
> + - clocks: Reference to the parent clock
> + - #clock-cells: Must be 1
> + - clock-output-names: The name of the clocks, must be "main", "pll1",
s/The name/The names/
> + "pll3", "lb", "qspi", "sdh", "sd0", "sd1".
> +
> +
> +Example
> +-------
> +
> + cpg_clocks: cpg_clocks {
> + compatible = "renesas,r8a7790-cpg-clocks";
> + reg = <0 0xe6150000 0 0x1000>;
> + clocks = <&extal_clk>;
> + #clock-cells = <1>;
> + clock-output-names = "main", "pll1", "pll3", "lb",
> + "qspi", "sdh", "sd0", "sd1";
> + };
I wonder if it makes sense to craft a more generic bindings document.
I am currently working on clock support for the r8a7779 (H1) based
on this patch series and I expect the bindings to end up being
more or less the same.
I expect there to be similar support to be added for many other renesas SoCs
over time.
> diff --git a/drivers/clk/shmobile/Makefile b/drivers/clk/shmobile/Makefile
> index 3275c78..949f29e 100644
> --- a/drivers/clk/shmobile/Makefile
> +++ b/drivers/clk/shmobile/Makefile
> @@ -1,4 +1,5 @@
> obj-$(CONFIG_ARCH_EMEV2) += clk-emev2.o
> +obj-$(CONFIG_ARCH_R8A7790) += clk-r8a7790.o
> obj-$(CONFIG_ARCH_SHMOBILE_MULTI) += clk-div6.o
> obj-$(CONFIG_ARCH_SHMOBILE_MULTI) += clk-mstp.o
>
> diff --git a/drivers/clk/shmobile/clk-r8a7790.c
> b/drivers/clk/shmobile/clk-r8a7790.c
> new file mode 100644
> index 0000000..2e76638
> --- /dev/null
> +++ b/drivers/clk/shmobile/clk-r8a7790.c
> @@ -0,0 +1,176 @@
> +/*
> + * r8a7790 Core CPG Clocks
> + *
> + * Copyright (C) 2013 Ideas On Board SPRL
> + *
> + * Contact: Laurent Pinchart <[email protected]>
> + *
> + * 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; version 2 of the License.
> + */
> +
> +#include <linux/clk-provider.h>
> +#include <linux/clkdev.h>
> +#include <linux/clk/shmobile.h>
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/spinlock.h>
> +
> +#include <dt-bindings/clock/r8a7790-clock.h>
> +
> +#define CPG_NUM_CLOCKS (R8A7790_CLK_SD1 + 1)
Perhaps R8A7790_NUM_CLOCKS in r8a7790-clock.h would be nicer.
> +
> +struct r8a7790_cpg {
> + struct clk_onecell_data data;
> + spinlock_t lock;
> + void __iomem *reg;
> +};
> +
> +/*
> + * MD EXTAL PLL0 PLL1 PLL3
> + * 14 13 19 (MHz) *1 *1
> + *---------------------------------------------------
> + * 0 0 0 15 x 1 x172/2 x208/2 x106
> + * 0 0 1 15 x 1 x172/2 x208/2 x88
> + * 0 1 0 20 x 1 x130/2 x156/2 x80
> + * 0 1 1 20 x 1 x130/2 x156/2 x66
> + * 1 0 0 26 / 2 x200/2 x240/2 x122
> + * 1 0 1 26 / 2 x200/2 x240/2 x102
> + * 1 1 0 30 / 2 x172/2 x208/2 x106
> + * 1 1 1 30 / 2 x172/2 x208/2 x88
> + *
> + * *1 : Table 7.6 indicates VCO ouput (PLLx = VCO/2)
> + */
> +#define CPG_PLL_CONFIG_INDEX(md) ((((md) & BIT(14)) >> 12) | \
> + (((md) & BIT(13)) >> 12) | \
> + (((md) & BIT(19)) >> 19))
> +struct cpg_pll_config {
> + unsigned int extal_div;
> + unsigned int pll1_mult;
> + unsigned int pll3_mult;
> +};
> +
> +static const struct cpg_pll_config cpg_pll_configs[8] = {
> + { 1, 208, 106 }, { 1, 208, 88 }, { 1, 156, 80 }, { 1, 156, 66 },
> + { 2, 240, 122 }, { 2, 240, 102 }, { 2, 208, 106 }, { 2, 208, 88 },
> +};
> +
> +/* SDHI divisors */
> +static const struct clk_div_table cpg_sdh_div_table[] = {
> + { 0, 2 }, { 1, 3 }, { 2, 4 }, { 3, 6 },
> + { 4, 8 }, { 5, 12 }, { 6, 16 }, { 7, 18 },
> + { 8, 24 }, { 10, 36 }, { 11, 48 }, { 0, 0 },
> +};
> +
> +static const struct clk_div_table cpg_sd01_div_table[] = {
> + { 5, 12 }, { 6, 16 }, { 7, 18 }, { 8, 24 },
> + { 10, 36 }, { 11, 48 }, { 12, 10 }, { 0, 0 },
> +};
Can any or all of the above three constants be __initconst?
> +
> +static u32 cpg_mode __initdata;
> +
> +#define CPG_SDCKCR 0x00000074
> +
> +static void __init r8a7790_cpg_clocks_init(struct device_node *np)
> +{
> + const struct cpg_pll_config *config;
> + struct r8a7790_cpg *cpg;
> + struct clk **clks;
> + unsigned int i;
> +
> + cpg = kzalloc(sizeof(*cpg), GFP_KERNEL);
Nit: s/sizeof(*cpg)/sizeof *cpg/, sizeof is an operator.
> + clks = kzalloc(CPG_NUM_CLOCKS * sizeof(*clks), GFP_KERNEL);
> + if (cpg == NULL || clks == NULL) {
> + kfree(clks);
> + kfree(cpg);
> + pr_err("%s: failed to allocate cpg\n", __func__);
> + return;
> + }
> +
> + spin_lock_init(&cpg->lock);
> +
> + cpg->data.clks = clks;
> + cpg->data.clk_num = CPG_NUM_CLOCKS;
> +
> + cpg->reg = of_iomap(np, 0);
> + if (WARN_ON(cpg->reg == NULL)) {
> + kfree(cpg->data.clks);
> + kfree(cpg);
> + return;
> + }
Perhaps this error checking could be merged with that of cpg and clks?
> +
> + config = &cpg_pll_configs[CPG_PLL_CONFIG_INDEX(cpg_mode)];
> +
> + for (i = 0; i < CPG_NUM_CLOCKS; ++i) {
> + const struct clk_div_table *table = NULL;
> + const char *parent_name = "main";
> + const char *name;
> + unsigned int shift;
> + unsigned int mult = 1;
> + unsigned int div = 1;
> + struct clk *clk;
> +
> + of_property_read_string_index(np, "clock-output-names", i,
> + &name);
> +
> + switch (i) {
> + case R8A7790_CLK_MAIN:
> + parent_name = of_clk_get_parent_name(np, 0);
> + div = config->extal_div;
> + break;
> + case R8A7790_CLK_PLL1:
> + mult = config->pll1_mult / 2;
> + break;
> + case R8A7790_CLK_PLL3:
> + mult = config->pll3_mult;
> + break;
> + case R8A7790_CLK_LB:
> + div = cpg_mode & BIT(18) ? 36 : 24;
> + break;
> + case R8A7790_CLK_QSPI:
> + div = (cpg_mode & (BIT(3) | BIT(2) | BIT(1))) == BIT(2)
> + ? 16 : 20;
> + break;
> + case R8A7790_CLK_SDH:
> + table = cpg_sdh_div_table;
> + shift = 8;
> + break;
> + case R8A7790_CLK_SD0:
> + table = cpg_sd01_div_table;
> + shift = 4;
> + break;
> + case R8A7790_CLK_SD1:
> + table = cpg_sd01_div_table;
> + shift = 0;
> + break;
> + }
I wonder if it would be good to and skip the portions below if the switch
statement hits a default: case.
Also, if i was an enum type then I think the C compiler would warn
about any missing cases. That might be nice too.
> +
> + if (!table)
> + clk = clk_register_fixed_factor(NULL, name, parent_name,
> + 0, mult, div);
> + else
> + clk = clk_register_divider_table(NULL, name,
> + parent_name, 0,
> + cpg->reg + CPG_SDCKCR,
> + shift, 4, 0, table,
> + &cpg->lock);
> +
> + if (IS_ERR(clk))
> + pr_err("%s: failed to register %s %s clock (%ld)\n",
> + __func__, np->name, name, PTR_ERR(clk));
> + }
> +
> + of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);
> +}
> +CLK_OF_DECLARE(r8a7790_cpg_clks, "renesas,r8a7790-cpg-clocks",
> + r8a7790_cpg_clocks_init);
> +
> +void __init r8a7790_clocks_init(u32 mode)
> +{
> + cpg_mode = mode;
> +
> + of_clk_init(NULL);
> +}
> diff --git a/include/dt-bindings/clock/r8a7790-clock.h
> b/include/dt-bindings/clock/r8a7790-clock.h
> index 19f2b48..f0ed742 100644
> --- a/include/dt-bindings/clock/r8a7790-clock.h
> +++ b/include/dt-bindings/clock/r8a7790-clock.h
> @@ -10,6 +10,16 @@
> #ifndef __DT_BINDINGS_CLOCK_R8A7790_H__
> #define __DT_BINDINGS_CLOCK_R8A7790_H__
>
> +/* CPG */
> +#define R8A7790_CLK_MAIN 0
> +#define R8A7790_CLK_PLL1 1
> +#define R8A7790_CLK_PLL3 2
> +#define R8A7790_CLK_LB 3
> +#define R8A7790_CLK_QSPI 4
> +#define R8A7790_CLK_SDH 5
> +#define R8A7790_CLK_SD0 6
> +#define R8A7790_CLK_SD1 7
> +
> /* MSTP1 */
> #define R8A7790_CLK_CMT0 20
>
> diff --git a/include/linux/clk/shmobile.h b/include/linux/clk/shmobile.h
> new file mode 100644
> index 0000000..b090855
> --- /dev/null
> +++ b/include/linux/clk/shmobile.h
> @@ -0,0 +1,19 @@
> +/*
> + * Copyright 2013 Ideas On Board SPRL
> + *
> + * Contact: Laurent Pinchart <[email protected]>
> + *
> + * 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.
> + */
> +
> +#ifndef __LINUX_CLK_SHMOBILE_H_
> +#define __LINUX_CLK_SHMOBILE_H_
> +
> +#include <linux/types.h>
> +
> +void r8a7790_clocks_init(u32 mode);
> +
> +#endif
> --
> 1.8.1.5
>
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