Re: RE: [PATCH v3] clk: add PowerPC corenet clock driver support
From: Mike Turquette
Date: Tue Apr 16 2013 - 18:27:33 EST
Quoting Tang Yuantian-B29983 (2013-04-15 23:59:34)
> Hi Mike,
>
> I really appreciate if you can spend some times to review this patch.
>
Yauntian,
Thanks for submitting this patch. I have frozen the changes I plan to
submit for 3.10, with the exception of any last-minute fixes. I'll take
a closer look at this after the merge window.
Regards,
Mike
> Thanks,
> Yuantian
>
>
> > -----Original Message-----
> > From: Tang Yuantian-B29983
> > Sent: 2013å4æ9æ 16:46
> > To: mturquette@xxxxxxxxxx
> > Cc: linus.walleij@xxxxxxxxxx; viresh.kumar@xxxxxxxxxx;
> > shawn.guo@xxxxxxxxxx; ulf.hansson@xxxxxxxxxx; linux-
> > kernel@xxxxxxxxxxxxxxx; devicetree-discuss@xxxxxxxxxxxxxxxx; linuxppc-
> > dev@xxxxxxxxxxxxxxxx; linux-doc@xxxxxxxxxxxxxxx; Tang Yuantian-B29983;
> > Tang Yuantian-B29983; Li Yang-R58472
> > Subject: [PATCH v3] clk: add PowerPC corenet clock driver support
> >
> > From: Tang Yuantian <yuantian.tang@xxxxxxxxxxxxx>
> >
> > This adds the clock driver for Freescale PowerPC corenet series SoCs
> > using common clock infrastructure.
> >
> > Signed-off-by: Tang Yuantian <Yuantian.Tang@xxxxxxxxxxxxx>
> > Signed-off-by: Li Yang <leoli@xxxxxxxxxxxxx>
> > ---
> > v3:
> > - remove the module author and description
> > v2:
> > - add the document for device tree clock bindings
> >
> > arch/powerpc/platforms/Kconfig.cputype | 1 +
> > drivers/clk/Kconfig | 7 +
> > drivers/clk/Makefile | 1 +
> > drivers/clk/clk-ppc-corenet.c | 280
> > +++++++++++++++++++++++++++++++++
> > 4 files changed, 289 insertions(+)
> > create mode 100644 drivers/clk/clk-ppc-corenet.c
> >
> > diff --git a/arch/powerpc/platforms/Kconfig.cputype
> > b/arch/powerpc/platforms/Kconfig.cputype
> > index 18e3b76..cf065b8 100644
> > --- a/arch/powerpc/platforms/Kconfig.cputype
> > +++ b/arch/powerpc/platforms/Kconfig.cputype
> > @@ -158,6 +158,7 @@ config E500
> > config PPC_E500MC
> > bool "e500mc Support"
> > select PPC_FPU
> > + select COMMON_CLK
> > depends on E500
> > help
> > This must be enabled for running on e500mc (and derivatives diff
> > --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig index a47e6ee..6e2fd9c
> > 100644
> > --- a/drivers/clk/Kconfig
> > +++ b/drivers/clk/Kconfig
> > @@ -63,6 +63,13 @@ config CLK_TWL6040
> > McPDM. McPDM module is using the external bit clock on the McPDM
> > bus
> > as functional clock.
> >
> > +config CLK_PPC_CORENET
> > + bool "Clock driver for PowerPC corenet platforms"
> > + depends on PPC_E500MC && OF
> > + ---help---
> > + This adds the clock driver support for Freescale PowerPC corenet
> > + platforms using common clock framework.
> > +
> > endmenu
> >
> > source "drivers/clk/mvebu/Kconfig"
> > diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile index
> > 300d477..6720319 100644
> > --- a/drivers/clk/Makefile
> > +++ b/drivers/clk/Makefile
> > @@ -34,3 +34,4 @@ obj-$(CONFIG_X86) += x86/
> > obj-$(CONFIG_COMMON_CLK_WM831X) += clk-wm831x.o
> > obj-$(CONFIG_COMMON_CLK_MAX77686) += clk-max77686.o
> > obj-$(CONFIG_CLK_TWL6040) += clk-twl6040.o
> > +obj-$(CONFIG_CLK_PPC_CORENET) += clk-ppc-corenet.o
> > diff --git a/drivers/clk/clk-ppc-corenet.c b/drivers/clk/clk-ppc-
> > corenet.c new file mode 100644 index 0000000..a2d483f
> > --- /dev/null
> > +++ b/drivers/clk/clk-ppc-corenet.c
> > @@ -0,0 +1,280 @@
> > +/*
> > + * Copyright 2013 Freescale Semiconductor, Inc.
> > + *
> > + * 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.
> > + *
> > + * clock driver for Freescale PowerPC corenet SoCs.
> > + */
> > +#include <linux/clk-provider.h>
> > +#include <linux/io.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/of_platform.h>
> > +#include <linux/of.h>
> > +#include <linux/slab.h>
> > +
> > +struct cmux_clk {
> > + struct clk_hw hw;
> > + void __iomem *reg;
> > + u32 flags;
> > +};
> > +
> > +#define PLL_KILL BIT(31)
> > +#define CLKSEL_SHIFT 27
> > +#define CLKSEL_ADJUST BIT(0)
> > +#define to_cmux_clk(p) container_of(p, struct cmux_clk, hw)
> > +
> > +static void __iomem *base;
> > +static unsigned int clocks_per_pll;
> > +
> > +static int cmux_set_parent(struct clk_hw *hw, u8 idx) {
> > + struct cmux_clk *clk = to_cmux_clk(hw);
> > + u32 clksel;
> > +
> > + clksel = ((idx / clocks_per_pll) << 2) + idx % clocks_per_pll;
> > + if (clk->flags & CLKSEL_ADJUST)
> > + clksel += 8;
> > + clksel = (clksel & 0xf) << CLKSEL_SHIFT;
> > + iowrite32be(clksel, clk->reg);
> > +
> > + return 0;
> > +}
> > +
> > +static u8 cmux_get_parent(struct clk_hw *hw) {
> > + struct cmux_clk *clk = to_cmux_clk(hw);
> > + u32 clksel;
> > +
> > + clksel = ioread32be(clk->reg);
> > + clksel = (clksel >> CLKSEL_SHIFT) & 0xf;
> > + if (clk->flags & CLKSEL_ADJUST)
> > + clksel -= 8;
> > + clksel = (clksel >> 2) * clocks_per_pll + clksel % 4;
> > +
> > + return clksel;
> > +}
> > +
> > +const struct clk_ops cmux_ops = {
> > + .get_parent = cmux_get_parent,
> > + .set_parent = cmux_set_parent,
> > +};
> > +
> > +static void __init core_mux_init(struct device_node *np) {
> > + struct clk *clk;
> > + struct clk_init_data init;
> > + struct cmux_clk *cmux_clk;
> > + struct device_node *node;
> > + int rc, count, i;
> > + u32 offset;
> > + const char *clk_name;
> > + const char **parent_names;
> > +
> > + rc = of_property_read_u32(np, "reg", &offset);
> > + if (rc) {
> > + pr_err("%s: could not get reg property\n", np->name);
> > + return;
> > + }
> > +
> > + /* get the input clock source count */
> > + count = of_property_count_strings(np, "clock-names");
> > + if (count < 0) {
> > + pr_err("%s: get clock count error\n", np->name);
> > + return;
> > + }
> > + parent_names = kzalloc((sizeof(char *) * count), GFP_KERNEL);
> > + if (!parent_names) {
> > + pr_err("%s: could not allocate parent_names\n", __func__);
> > + return;
> > + }
> > +
> > + for (i = 0; i < count; i++)
> > + parent_names[i] = of_clk_get_parent_name(np, i);
> > +
> > + cmux_clk = kzalloc(sizeof(struct cmux_clk), GFP_KERNEL);
> > + if (!cmux_clk) {
> > + pr_err("%s: could not allocate cmux_clk\n", __func__);
> > + goto err_name;
> > + }
> > + cmux_clk->reg = base + offset;
> > +
> > + node = of_find_compatible_node(NULL, NULL, "fsl,p4080-clockgen");
> > + if (node && (offset >= 0x80))
> > + cmux_clk->flags = CLKSEL_ADJUST;
> > +
> > + rc = of_property_read_string_index(np, "clock-output-names",
> > + 0, &clk_name);
> > + if (rc) {
> > + pr_err("%s: read clock names error\n", np->name);
> > + goto err_clk;
> > + }
> > +
> > + init.name = clk_name;
> > + init.ops = &cmux_ops;
> > + init.parent_names = parent_names;
> > + init.num_parents = count;
> > + init.flags = 0;
> > + cmux_clk->hw.init = &init;
> > +
> > + clk = clk_register(NULL, &cmux_clk->hw);
> > + if (IS_ERR(clk)) {
> > + pr_err("%s: could not register clock\n", clk_name);
> > + goto err_clk;
> > + }
> > +
> > + rc = of_clk_add_provider(np, of_clk_src_simple_get, clk);
> > + if (rc) {
> > + pr_err("Could not register clock provider for node:%s\n",
> > + np->name);
> > + goto err_clk;
> > + }
> > + goto err_name;
> > +
> > +err_clk:
> > + kfree(cmux_clk);
> > +err_name:
> > + /* free *_names because they are reallocated when registered */
> > + kfree(parent_names);
> > +}
> > +
> > +static void __init core_pll_init(struct device_node *np) {
> > + u32 offset, mult;
> > + int i, rc, count;
> > + const char *clk_name, *parent_name;
> > + struct clk_onecell_data *onecell_data;
> > + struct clk **subclks;
> > +
> > + rc = of_property_read_u32(np, "reg", &offset);
> > + if (rc) {
> > + pr_err("%s: could not get reg property\n", np->name);
> > + return;
> > + }
> > +
> > + /* get the multiple of PLL */
> > + mult = ioread32be(base + offset);
> > +
> > + /* check if this PLL is disabled */
> > + if (mult & PLL_KILL) {
> > + pr_debug("PLL:%s is disabled\n", np->name);
> > + return;
> > + }
> > + mult = (mult >> 1) & 0x3f;
> > +
> > + parent_name = of_clk_get_parent_name(np, 0);
> > + if (!parent_name) {
> > + pr_err("PLL: %s must have a parent\n", np->name);
> > + return;
> > + }
> > +
> > + count = of_property_count_strings(np, "clock-output-names");
> > + if (count < 0 || count > 4) {
> > + pr_err("%s: clock is not supported\n", np->name);
> > + return;
> > + }
> > +
> > + /* output clock number per PLL */
> > + clocks_per_pll = count;
> > +
> > + subclks = kzalloc(sizeof(struct clk *) * count, GFP_KERNEL);
> > + if (!subclks) {
> > + pr_err("%s: could not allocate subclks\n", __func__);
> > + return;
> > + }
> > +
> > + onecell_data = kzalloc(sizeof(struct clk_onecell_data), GFP_KERNEL);
> > + if (!onecell_data) {
> > + pr_err("%s: could not allocate onecell_data\n", __func__);
> > + goto err_clks;
> > + }
> > +
> > + for (i = 0; i < count; i++) {
> > + rc = of_property_read_string_index(np, "clock-output-names",
> > + i, &clk_name);
> > + if (rc) {
> > + pr_err("%s: could not get clock names\n", np->name);
> > + goto err_cell;
> > + }
> > +
> > + /*
> > + * when count == 4, there are 4 output clocks:
> > + * /1, /2, /3, /4 respectively
> > + * when count < 4, there are at least 2 output clocks:
> > + * /1, /2, (/4, if count == 3) respectively.
> > + */
> > + if (count == 4)
> > + subclks[i] = clk_register_fixed_factor(NULL, clk_name,
> > + parent_name, 0, mult, 1 + i);
> > + else
> > +
> > + subclks[i] = clk_register_fixed_factor(NULL, clk_name,
> > + parent_name, 0, mult, 1 << i);
> > +
> > + if (IS_ERR(subclks[i])) {
> > + pr_err("%s: could not register clock\n", clk_name);
> > + goto err_cell;
> > + }
> > + }
> > +
> > + onecell_data->clks = subclks;
> > + onecell_data->clk_num = count;
> > +
> > + rc = of_clk_add_provider(np, of_clk_src_onecell_get, onecell_data);
> > + if (rc) {
> > + pr_err("Could not register clk provider for node:%s\n",
> > + np->name);
> > + goto err_cell;
> > + }
> > +
> > + return;
> > +err_cell:
> > + kfree(onecell_data);
> > +err_clks:
> > + kfree(subclks);
> > +}
> > +
> > +static const struct of_device_id clk_match[] __initconst = {
> > + { .compatible = "fixed-clock", .data = of_fixed_clk_setup, },
> > + { .compatible = "fsl,core-pll-clock", .data = core_pll_init, },
> > + { .compatible = "fsl,core-mux-clock", .data = core_mux_init, },
> > + {}
> > +};
> > +
> > +static int __init ppc_corenet_clk_probe(struct platform_device *pdev) {
> > + struct device_node *np;
> > +
> > + np = pdev->dev.of_node;
> > + base = of_iomap(np, 0);
> > + if (!base) {
> > + dev_err(&pdev->dev, "iomap error\n");
> > + return -ENOMEM;
> > + }
> > + of_clk_init(clk_match);
> > +
> > + return 0;
> > +}
> > +
> > +static const struct of_device_id ppc_clk_ids[] __initconst = {
> > + { .compatible = "fsl,qoriq-clockgen-1.0", },
> > + { .compatible = "fsl,qoriq-clockgen-2", },
> > + {}
> > +};
> > +
> > +static struct platform_driver ppc_corenet_clk_driver = {
> > + .driver = {
> > + .name = "ppc_corenet_clock",
> > + .owner = THIS_MODULE,
> > + .of_match_table = ppc_clk_ids,
> > + },
> > + .probe = ppc_corenet_clk_probe,
> > +};
> > +
> > +static int __init ppc_corenet_clk_init(void) {
> > + return platform_driver_register(&ppc_corenet_clk_driver);
> > +}
> > +subsys_initcall(ppc_corenet_clk_init);
> > --
> > 1.8.0
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