| Message ID | 1394105552-9744-2-git-send-email-wsa@the-dreams.de (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
Hi Wolfram, Thank you for the patch. On Thursday 06 March 2014 12:32:21 Wolfram Sang wrote: > From: Wolfram Sang <wsa@sang-engineering.com> > > Signed-off-by: Wolfram Sang <wsa@sang-engineering.com> > --- > > Changes since V1: > * added docs > * preparation for usb_x1 support by documenting two input clocks > * static-consted frqcr_tab > * bail out if num_clks == 0 > * cosmetic fixes > > Mike: if you are fine with this driver, it would be good if you could apply > it. Then, we can deal with the orthogonal dependencies in mach-shmobile > seperately and know that the driver is already in place when the rest gets > resolved. Thanks! > > .../bindings/clock/renesas,rz-cpg-clocks.txt | 29 ++++++ > drivers/clk/shmobile/Makefile | 1 + > drivers/clk/shmobile/clk-rz.c | 113 ++++++++++++++++++ > 3 files changed, 143 insertions(+) > create mode 100644 > Documentation/devicetree/bindings/clock/renesas,rz-cpg-clocks.txt create > mode 100644 drivers/clk/shmobile/clk-rz.c > > diff --git > a/Documentation/devicetree/bindings/clock/renesas,rz-cpg-clocks.txt > b/Documentation/devicetree/bindings/clock/renesas,rz-cpg-clocks.txt new > file mode 100644 > index 000000000000..c8e8821f08f6 > --- /dev/null > +++ b/Documentation/devicetree/bindings/clock/renesas,rz-cpg-clocks.txt > @@ -0,0 +1,29 @@ > +* Renesas RZ Clock Pulse Generator (CPG) > + > +The CPG generates core clocks for the RZ SoCs. It includes the PLL, > variable +CPU and GPU clocks, and several fixed ratio dividers. > + > +Required Properties: > + > + - compatible: Must be one of > + - "renesas,r7s72100-cpg-clocks" for the r7s72100 CPG > + - "renesas,rz-cpg-clocks" for the generic RZ CPG > + - reg: Base address and length of the memory resource used by the CPG > + - clocks: References to possible parent clocks. Order must match clock > modes > + in the datasheet. I believe the order should be documented explicitly instead of referring to the datasheet. > + - #clock-cells: Must be 1 > + - clock-output-names: The names of the clocks. Supported clocks are > "pll", > + "i", and "g" > + > + > +Example > +------- > + > + cpg_clocks: cpg_clocks@fcfe0000 { > + #clock-cells = <1>; > + compatible = "renesas,r7s72100-cpg-clocks", > + "renesas,rz-cpg-clocks"; > + reg = <0xfcfe0000 0x18>; > + clocks = <&extal_clk>, <&usb_x1_clk>; > + clock-output-names = "pll", "i", "g"; > + }; > diff --git a/drivers/clk/shmobile/Makefile b/drivers/clk/shmobile/Makefile > index 9ecef140dba7..5404cb931ebf 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_R7S72100) += clk-rz.o > obj-$(CONFIG_ARCH_R8A7790) += clk-rcar-gen2.o > obj-$(CONFIG_ARCH_R8A7791) += clk-rcar-gen2.o > obj-$(CONFIG_ARCH_SHMOBILE_MULTI) += clk-div6.o > diff --git a/drivers/clk/shmobile/clk-rz.c b/drivers/clk/shmobile/clk-rz.c > new file mode 100644 > index 000000000000..2901db3ac5d3 > --- /dev/null > +++ b/drivers/clk/shmobile/clk-rz.c > @@ -0,0 +1,113 @@ > +/* > + * rz Core CPG Clocks > + * > + * Copyright (C) 2013 Ideas On Board SPRL > + * Copyright (C) 2014 Wolfram Sang, Sang Engineering > <wsa@sang-engineering.com> + * > + * 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/init.h> > +#include <linux/kernel.h> > +#include <linux/of.h> > +#include <linux/of_address.h> > +#include <linux/slab.h> > + > +struct rz_cpg { > + struct clk_onecell_data data; > + void __iomem *reg; > +}; > + > +#define CPG_FRQCR 0x10 > +#define CPG_FRQCR2 0x14 > + > +/* > --------------------------------------------------------------------------- > -- + * Initialization > + */ > + > +static struct clk * __init > +rz_cpg_register_clock(struct device_node *np, struct rz_cpg *cpg, const > char *name) > +{ > + u32 val; > + unsigned mult; > + static const unsigned frqcr_tab[4] = { 3, 2, 0, 1 }; > + > + if (strcmp(name, "pll") == 0) { > + /* FIXME: cpg_mode should be read from GPIO. But no GPIO support yet > */ > + unsigned cpg_mode = 0; /* hardcoded to EXTAL for now */ > + const char *parent_name = of_clk_get_parent_name(np, cpg_mode); > + > + mult = cpg_mode ? (32 / 4) : 30; > + > + return clk_register_fixed_factor(NULL, name, parent_name, 0, mult, > 1); > + } > + > + /* FIXME:"i" and "g" are variable clocks with non-integer dividers (e.g. > 2/3) > + * and the constraint that always g <= i. To get the rz platform started, > + * let them run at fixed current speed and implement the details later. > + */ > + if (strcmp(name, "i") == 0) > + val = (clk_readl(cpg->reg + CPG_FRQCR) >> 8) & 3; > + else if (strcmp(name, "g") == 0) > + val = clk_readl(cpg->reg + CPG_FRQCR2) & 3; > + else > + return ERR_PTR(-EINVAL); > + > + mult = frqcr_tab[val]; > + return clk_register_fixed_factor(NULL, name, "pll", 0, mult, 3); > +} > + > +static void __init rz_cpg_clocks_init(struct device_node *np) > +{ > + struct rz_cpg *cpg; > + struct clk **clks; > + unsigned i; > + int num_clks; > + > + num_clks = of_property_count_strings(np, "clock-output-names"); > + if (WARN(num_clks <= 0, "can't count CPG clocks\n")) > + goto out; You can return directly instead of goto out. > + > + cpg = kzalloc(sizeof(*cpg), GFP_KERNEL); > + if (WARN(!cpg, "out of memory!\n")) kmalloc() warns already when it can't allocate memory, so you can remove the warning here. > + goto out; You can return directly here too. > + > + clks = kzalloc(num_clks * sizeof(*clks), GFP_KERNEL); > + if (WARN(!clks, "out of memory!\n")) You can remove this warning too. > + goto free_cpg; > + > + cpg->data.clks = clks; > + cpg->data.clk_num = num_clks; > + > + cpg->reg = of_iomap(np, 0); > + if (WARN(!cpg->reg, "can't remap CPG registers!\n")) > + goto free_clks; > + > + for (i = 0; i < num_clks; ++i) { > + const char *name; > + struct clk *clk; > + > + of_property_read_string_index(np, "clock-output-names", i, &name); > + > + clk = rz_cpg_register_clock(np, cpg, name); > + if (IS_ERR(clk)) > + pr_err("%s: failed to register %s %s clock (%ld)\n", > + __func__, np->name, name, PTR_ERR(clk)); > + else > + cpg->data.clks[i] = clk; > + } > + > + of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data); > + return; > + > +free_clks: > + kfree(clks); > +free_cpg: > + kfree(cpg); > +out: > + return; No need for an explicit return. > +} > +CLK_OF_DECLARE(rz_cpg_clks, "renesas,rz-cpg-clocks", rz_cpg_clocks_init);
> > + - clocks: References to possible parent clocks. Order must match clock > > modes > > + in the datasheet. > > I believe the order should be documented explicitly instead of referring to > the datasheet. I wanted to keep it generic in case future SoCs want to use the driver. > > + num_clks = of_property_count_strings(np, "clock-output-names"); > > + if (WARN(num_clks <= 0, "can't count CPG clocks\n")) > > + goto out; > > You can return directly instead of goto out. I personally don't prefer the mixture of goto and direct return. Please say if you insist on that.
Hi Wolfram, On Thu, Mar 6, 2014 at 2:06 PM, Wolfram Sang <wsa@the-dreams.de> wrote: >> > + num_clks = of_property_count_strings(np, "clock-output-names"); >> > + if (WARN(num_clks <= 0, "can't count CPG clocks\n")) >> > + goto out; >> >> You can return directly instead of goto out. > > I personally don't prefer the mixture of goto and direct return. Please > say if you insist on that. Here it's not really a mix: there is a strict separation between cases where cleanup/error handling is done and case where it's not. So it serves as a clue for the reader, who doesn't have to scroll down to see that no cleanup/error handling is done later. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-sh" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/devicetree/bindings/clock/renesas,rz-cpg-clocks.txt b/Documentation/devicetree/bindings/clock/renesas,rz-cpg-clocks.txt new file mode 100644 index 000000000000..c8e8821f08f6 --- /dev/null +++ b/Documentation/devicetree/bindings/clock/renesas,rz-cpg-clocks.txt @@ -0,0 +1,29 @@ +* Renesas RZ Clock Pulse Generator (CPG) + +The CPG generates core clocks for the RZ SoCs. It includes the PLL, variable +CPU and GPU clocks, and several fixed ratio dividers. + +Required Properties: + + - compatible: Must be one of + - "renesas,r7s72100-cpg-clocks" for the r7s72100 CPG + - "renesas,rz-cpg-clocks" for the generic RZ CPG + - reg: Base address and length of the memory resource used by the CPG + - clocks: References to possible parent clocks. Order must match clock modes + in the datasheet. + - #clock-cells: Must be 1 + - clock-output-names: The names of the clocks. Supported clocks are "pll", + "i", and "g" + + +Example +------- + + cpg_clocks: cpg_clocks@fcfe0000 { + #clock-cells = <1>; + compatible = "renesas,r7s72100-cpg-clocks", + "renesas,rz-cpg-clocks"; + reg = <0xfcfe0000 0x18>; + clocks = <&extal_clk>, <&usb_x1_clk>; + clock-output-names = "pll", "i", "g"; + }; diff --git a/drivers/clk/shmobile/Makefile b/drivers/clk/shmobile/Makefile index 9ecef140dba7..5404cb931ebf 100644 --- a/drivers/clk/shmobile/Makefile +++ b/drivers/clk/shmobile/Makefile @@ -1,4 +1,5 @@ obj-$(CONFIG_ARCH_EMEV2) += clk-emev2.o +obj-$(CONFIG_ARCH_R7S72100) += clk-rz.o obj-$(CONFIG_ARCH_R8A7790) += clk-rcar-gen2.o obj-$(CONFIG_ARCH_R8A7791) += clk-rcar-gen2.o obj-$(CONFIG_ARCH_SHMOBILE_MULTI) += clk-div6.o diff --git a/drivers/clk/shmobile/clk-rz.c b/drivers/clk/shmobile/clk-rz.c new file mode 100644 index 000000000000..2901db3ac5d3 --- /dev/null +++ b/drivers/clk/shmobile/clk-rz.c @@ -0,0 +1,113 @@ +/* + * rz Core CPG Clocks + * + * Copyright (C) 2013 Ideas On Board SPRL + * Copyright (C) 2014 Wolfram Sang, Sang Engineering <wsa@sang-engineering.com> + * + * 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/init.h> +#include <linux/kernel.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/slab.h> + +struct rz_cpg { + struct clk_onecell_data data; + void __iomem *reg; +}; + +#define CPG_FRQCR 0x10 +#define CPG_FRQCR2 0x14 + +/* ----------------------------------------------------------------------------- + * Initialization + */ + +static struct clk * __init +rz_cpg_register_clock(struct device_node *np, struct rz_cpg *cpg, const char *name) +{ + u32 val; + unsigned mult; + static const unsigned frqcr_tab[4] = { 3, 2, 0, 1 }; + + if (strcmp(name, "pll") == 0) { + /* FIXME: cpg_mode should be read from GPIO. But no GPIO support yet */ + unsigned cpg_mode = 0; /* hardcoded to EXTAL for now */ + const char *parent_name = of_clk_get_parent_name(np, cpg_mode); + + mult = cpg_mode ? (32 / 4) : 30; + + return clk_register_fixed_factor(NULL, name, parent_name, 0, mult, 1); + } + + /* FIXME:"i" and "g" are variable clocks with non-integer dividers (e.g. 2/3) + * and the constraint that always g <= i. To get the rz platform started, + * let them run at fixed current speed and implement the details later. + */ + if (strcmp(name, "i") == 0) + val = (clk_readl(cpg->reg + CPG_FRQCR) >> 8) & 3; + else if (strcmp(name, "g") == 0) + val = clk_readl(cpg->reg + CPG_FRQCR2) & 3; + else + return ERR_PTR(-EINVAL); + + mult = frqcr_tab[val]; + return clk_register_fixed_factor(NULL, name, "pll", 0, mult, 3); +} + +static void __init rz_cpg_clocks_init(struct device_node *np) +{ + struct rz_cpg *cpg; + struct clk **clks; + unsigned i; + int num_clks; + + num_clks = of_property_count_strings(np, "clock-output-names"); + if (WARN(num_clks <= 0, "can't count CPG clocks\n")) + goto out; + + cpg = kzalloc(sizeof(*cpg), GFP_KERNEL); + if (WARN(!cpg, "out of memory!\n")) + goto out; + + clks = kzalloc(num_clks * sizeof(*clks), GFP_KERNEL); + if (WARN(!clks, "out of memory!\n")) + goto free_cpg; + + cpg->data.clks = clks; + cpg->data.clk_num = num_clks; + + cpg->reg = of_iomap(np, 0); + if (WARN(!cpg->reg, "can't remap CPG registers!\n")) + goto free_clks; + + for (i = 0; i < num_clks; ++i) { + const char *name; + struct clk *clk; + + of_property_read_string_index(np, "clock-output-names", i, &name); + + clk = rz_cpg_register_clock(np, cpg, name); + if (IS_ERR(clk)) + pr_err("%s: failed to register %s %s clock (%ld)\n", + __func__, np->name, name, PTR_ERR(clk)); + else + cpg->data.clks[i] = clk; + } + + of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data); + return; + +free_clks: + kfree(clks); +free_cpg: + kfree(cpg); +out: + return; +} +CLK_OF_DECLARE(rz_cpg_clks, "renesas,rz-cpg-clocks", rz_cpg_clocks_init);