Re: [PATCH] clk: mediatek: Export CPU mux clocks for CPU frequency control

On Wed, Jul 15, 2015 at 02:38:46PM +0800, Pi-Cheng Chen wrote:

From: "pi-cheng.chen" pi-cheng.chen@linaro.org

This patch adds CPU mux clocks which are used by Mediatek cpufreq driver for intermediate clock source switching.

Hi Mike and Stephen,

since the MT8173 cpufreq driver is likely going to be merged[1] and we still need the CPU MUX clocks consumed by MT8173 cpufreq driver, may I have some comments from you to get this patch moving forwards so that MT8173 cpufreq driver could work completely?

Or the regmap supported basic clock type[2] is the prefered way? Thanks.

Best Regards, Pi-Cheng

[1] http://marc.info/?l=linux-pm&m=143850044118837&w=2 [2] http://marc.info/?l=linux-kernel&m=143835585905028&w=2

Signed-off-by: Pi-Cheng Chen pi-cheng.chen@linaro.org Reviewed-by: Daniel Kurtz djkurtz@chromium.org

---

Changes in v4:

• Address comments for v3
• Rebase to the patch that adds 13mhz clock for MT8173[1]

Changes in v3:

• Rebase to 4.2-rc1
• Fix some issues of v2

Changes in v2:

• Remove use of .determine_rate callback

[1] http://patchwork.kernerl.xyz/patch/6777041/

drivers/clk/mediatek/Makefile | 2 +- drivers/clk/mediatek/clk-cpumux.c | 127 +++++++++++++++++++++++++++++++++ drivers/clk/mediatek/clk-cpumux.h | 22 ++++++ drivers/clk/mediatek/clk-mt8173.c | 23 ++++++ include/dt-bindings/clock/mt8173-clk.h | 4 +- 5 files changed, 176 insertions(+), 2 deletions(-) create mode 100644 drivers/clk/mediatek/clk-cpumux.c create mode 100644 drivers/clk/mediatek/clk-cpumux.h

diff --git a/drivers/clk/mediatek/Makefile b/drivers/clk/mediatek/Makefile index 8e4b2a4..299917a 100644 --- a/drivers/clk/mediatek/Makefile +++ b/drivers/clk/mediatek/Makefile @@ -1,4 +1,4 @@ -obj-y += clk-mtk.o clk-pll.o clk-gate.o +obj-y += clk-mtk.o clk-pll.o clk-gate.o clk-cpumux.o obj-$(CONFIG_RESET_CONTROLLER) += reset.o obj-y += clk-mt8135.o obj-y += clk-mt8173.o diff --git a/drivers/clk/mediatek/clk-cpumux.c b/drivers/clk/mediatek/clk-cpumux.c new file mode 100644 index 0000000..fb04fe1 --- /dev/null +++ b/drivers/clk/mediatek/clk-cpumux.c @@ -0,0 +1,127 @@ +/*

• • Copyright (c) 2015 Linaro Ltd.
• • Author: Pi-Cheng Chen pi-cheng.chen@linaro.org
• • 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.
• • 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.
• */

+#include <linux/clk-provider.h> +#include <linux/mfd/syscon.h> +#include <linux/slab.h>

+#include "clk-mtk.h" +#include "clk-cpumux.h"

+struct mtk_clk_cpumux {

• struct clk_hw hw;
• struct regmap *regmap;
• u32 reg;
• u32 mask;
• u8 shift;

+};

+static inline struct mtk_clk_cpumux *to_clk_mux(struct clk_hw *_hw) +{

• return container_of(_hw, struct mtk_clk_cpumux, hw);

+}

+static u8 clk_cpumux_get_parent(struct clk_hw *hw) +{

• struct mtk_clk_cpumux *mux = to_clk_mux(hw);
• int num_parents = __clk_get_num_parents(hw->clk);
• unsigned int val;
• regmap_read(mux->regmap, mux->reg, &val);
• val >>= mux->shift;
• val &= mux->mask;
• if (val >= num_parents)

• return -EINVAL;
  

• return val;

+}

+static int clk_cpumux_set_parent(struct clk_hw *hw, u8 index) +{

• struct mtk_clk_cpumux *mux = to_clk_mux(hw);
• u32 mask, val;
• val = index << mux->shift;
• mask = mux->mask << mux->shift;
• return regmap_update_bits(mux->regmap, mux->reg, mask, val);

+}

+static const struct clk_ops clk_cpumux_ops = {

• .get_parent = clk_cpumux_get_parent,
• .set_parent = clk_cpumux_set_parent,

+};

+static struct clk __init *mtk_clk_register_cpumux(const struct mtk_composite *mux,

• 			   struct regmap *regmap)
  

+{

• struct mtk_clk_cpumux *cpumux;
• struct clk *clk;
• struct clk_init_data init;
• cpumux = kzalloc(sizeof(*cpumux), GFP_KERNEL);
• if (!cpumux)

• return ERR_PTR(-ENOMEM);
  

• init.name = mux->name;
• init.ops = &clk_cpumux_ops;
• init.parent_names = mux->parent_names;
• init.num_parents = mux->num_parents;
• init.flags = mux->flags;
• cpumux->reg = mux->mux_reg;
• cpumux->shift = mux->mux_shift;
• cpumux->mask = BIT(mux->mux_width) - 1;
• cpumux->regmap = regmap;
• cpumux->hw.init = &init;
• clk = clk_register(NULL, &cpumux->hw);
• if (IS_ERR(clk))

• kfree(cpumux);
  

• return clk;

+}

+int __init mtk_clk_register_cpumuxes(struct device_node *node,

• 	      const struct mtk_composite *clks, int num,
  

• 	      struct clk_onecell_data *clk_data)
  

+{

• int i;
• struct clk *clk;
• struct regmap *regmap;
• regmap = syscon_node_to_regmap(node);
• if (IS_ERR(regmap)) {

• pr_err("Cannot find regmap for %s: %ld\n", node->full_name,
  

•        PTR_ERR(regmap));
  

• return PTR_ERR(regmap);
  

• }
• for (i = 0; i < num; i++) {

• const struct mtk_composite *mux = &clks[i];
  

• clk = mtk_clk_register_cpumux(mux, regmap);
  

• if (IS_ERR(clk)) {
  

• 	pr_err("Failed to register clk %s: %ld\n",
  

• 	       mux->name, PTR_ERR(clk));
  

• 	continue;
  

• }
  

• clk_data->clks[mux->id] = clk;
  

• }
• return 0;

+} diff --git a/drivers/clk/mediatek/clk-cpumux.h b/drivers/clk/mediatek/clk-cpumux.h new file mode 100644 index 0000000..52c769f --- /dev/null +++ b/drivers/clk/mediatek/clk-cpumux.h @@ -0,0 +1,22 @@ +/*

• • Copyright (c) 2015 Linaro Ltd.
• • Author: Pi-Cheng Chen pi-cheng.chen@linaro.org
• • 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.
• • 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.
• */

+#ifndef __DRV_CLK_CPUMUX_H +#define __DRV_CLK_CPUMUX_H

+int mtk_clk_register_cpumuxes(struct device_node *node,

• 	      const struct mtk_composite *clks, int num,
  

• 	      struct clk_onecell_data *clk_data);
  

+#endif /* __DRV_CLK_CPUMUX_H */ diff --git a/drivers/clk/mediatek/clk-mt8173.c b/drivers/clk/mediatek/clk-mt8173.c index 540c5c3..053ca27 100644 --- a/drivers/clk/mediatek/clk-mt8173.c +++ b/drivers/clk/mediatek/clk-mt8173.c @@ -19,6 +19,7 @@ #include "clk-mtk.h" #include "clk-gate.h" +#include "clk-cpumux.h" #include <dt-bindings/clock/mt8173-clk.h> @@ -517,6 +518,25 @@ static const char * const i2s3_b_ck_parents[] __initconst = { "apll2_div5" }; +static const char * const ca53_parents[] __initconst = {

• "clk26m",
• "armca7pll",
• "mainpll",
• "univpll"

+};

+static const char * const ca57_parents[] __initconst = {

• "clk26m",
• "armca15pll",
• "mainpll",
• "univpll"

+};

+static const struct mtk_composite cpu_muxes[] __initconst = {

• MUX(CLK_INFRA_CA53SEL, "infra_ca53_sel", ca53_parents, 0x0000, 0, 2),
• MUX(CLK_INFRA_CA57SEL, "infra_ca57_sel", ca57_parents, 0x0000, 2, 2),

+};

static const struct mtk_composite top_muxes[] __initconst = { /* CLK_CFG_0 */ MUX(CLK_TOP_AXI_SEL, "axi_sel", axi_parents, 0x0040, 0, 3), @@ -743,6 +763,9 @@ static void __init mtk_infrasys_init(struct device_node *node) clk_data); mtk_clk_register_factors(infra_divs, ARRAY_SIZE(infra_divs), clk_data);

• mtk_clk_register_cpumuxes(node, cpu_muxes, ARRAY_SIZE(cpu_muxes),

• 				clk_data);
  

• r = of_clk_add_provider(node, of_clk_src_onecell_get, clk_data); if (r) pr_err("%s(): could not register clock provider: %d\n",

diff --git a/include/dt-bindings/clock/mt8173-clk.h b/include/dt-bindings/clock/mt8173-clk.h index fa2a2bb..a17cbaa 100644 --- a/include/dt-bindings/clock/mt8173-clk.h +++ b/include/dt-bindings/clock/mt8173-clk.h @@ -188,7 +188,9 @@ #define CLK_INFRA_PMICSPI 10 #define CLK_INFRA_PMICWRAP 11 #define CLK_INFRA_CLK_13M 12 -#define CLK_INFRA_NR_CLK 13 +#define CLK_INFRA_CA53SEL 13 +#define CLK_INFRA_CA57SEL 14 +#define CLK_INFRA_NR_CLK 15 /* PERI_SYS */ -- 1.9.1