[PATCH v3 03/10] clk: qcom: Add CPU clock driver for msm8996
Stephen Boyd
sboyd at kernel.org
Mon Mar 19 10:36:44 PDT 2018
Quoting Ilia Lin (2018-02-14 05:59:45)
> From: Rajendra Nayak <rnayak at codeaurora.org>
>
> Each of the CPU clusters (Power and Perf) on msm8996 are
> clocked via 2 PLLs, a primary and alternate. There are also
> 2 Mux'es, a primary and secondary all connected together
> as shown below
>
> +-------+
> XO | |
> +------------------>0 |
> | |
> PLL/2 | SMUX +----+
> +------->1 | |
> | | | |
> | +-------+ | +-------+
> | +---->0 |
> | | |
> +---------------+ | +----------->1 | CPU clk
> |Primary PLL +----+ PLL_EARLY | | +------>
> | +------+-----------+ +------>2 PMUX |
> +---------------+ | | | |
> | +------+ | +-->3 |
> +--^+ ACD +-----+ | +-------+
> +---------------+ +------+ |
> |Alt PLL | |
> | +---------------------------+
> +---------------+ PLL_EARLY
Thanks for the diagram. Please also put it at the top of the driver
file.
>
> The primary PLL is what drives the CPU clk, except for times
> when we are reprogramming the PLL itself (for rate changes) when
> we temporarily switch to an alternate PLL. A subsequent patch adds
> support to switch between primary and alternate PLL during rate
> changes.
>
> The primary PLL operates on a single VCO range, between 600Mhz
> and 3Ghz. However the CPUs do support OPPs with frequencies
> between 300Mhz and 600Mhz. In order to support running the CPUs
> at those frequencies we end up having to lock the PLL at twice
> the rate and drive the CPU clk via the PLL/2 output and SMUX.
>
> So for frequencies above 600Mhz we follow the following path
> Primary PLL --> PLL_EARLY --> PMUX(1) --> CPU clk
> and for frequencies between 300Mhz and 600Mhz we follow
Capitalize 'h' in units please.
> Primary PLL --> PLL/2 --> SMUX(1) --> PMUX(0) --> CPU clk
> Support for this is added in a subsequent patch as well.
>
> ACD stands for Adaptive Clock Distribution and is used to
> detect voltage droops. We do not add support for ACD as yet.
> This can be added at a later point as needed.
>
> Signed-off-by: Rajendra Nayak <rnayak at codeaurora.org>
> Signed-off-by: Ilia Lin <ilialin at codeaurora.org>
> ---
> drivers/clk/qcom/Kconfig | 8 +
> drivers/clk/qcom/Makefile | 1 +
> drivers/clk/qcom/clk-cpu-8996.c | 409 ++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 418 insertions(+)
> create mode 100644 drivers/clk/qcom/clk-cpu-8996.c
>
> diff --git a/drivers/clk/qcom/Kconfig b/drivers/clk/qcom/Kconfig
> index fbf4532..3274877 100644
> --- a/drivers/clk/qcom/Kconfig
> +++ b/drivers/clk/qcom/Kconfig
> @@ -226,3 +226,11 @@ config SPMI_PMIC_CLKDIV
> Technologies, Inc. SPMI PMIC. It configures the frequency of
> clkdiv outputs of the PMIC. These clocks are typically wired
> through alternate functions on GPIO pins.
> +
> +config MSM_APCC_8996
> + tristate "MSM8996 CPU Clock Controller"
> + depends on COMMON_CLK_QCOM
> + help
> + Support for the CPU clock controller on msm8996 devices.
> + Say Y if you want to support CPU clock scaling using CPUfreq
> + drivers for dyanmic power management.
Sort?
> diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
> index 230332c..57b38ba 100644
> --- a/drivers/clk/qcom/Makefile
> +++ b/drivers/clk/qcom/Makefile
> @@ -33,6 +33,7 @@ obj-$(CONFIG_MSM_LCC_8960) += lcc-msm8960.o
> obj-$(CONFIG_MSM_MMCC_8960) += mmcc-msm8960.o
> obj-$(CONFIG_MSM_MMCC_8974) += mmcc-msm8974.o
> obj-$(CONFIG_MSM_MMCC_8996) += mmcc-msm8996.o
> +obj-$(CONFIG_MSM_APCC_8996) += clk-cpu-8996.o
This doesn't look sorted.
> obj-$(CONFIG_QCOM_A53PLL) += a53-pll.o
> obj-$(CONFIG_QCOM_CLK_APCS_MSM8916) += apcs-msm8916.o
> obj-$(CONFIG_QCOM_CLK_RPM) += clk-rpm.o
> diff --git a/drivers/clk/qcom/clk-cpu-8996.c b/drivers/clk/qcom/clk-cpu-8996.c
> new file mode 100644
> index 0000000..42489f1
> --- /dev/null
> +++ b/drivers/clk/qcom/clk-cpu-8996.c
> @@ -0,0 +1,409 @@
> +/*
> + * Copyright (c) 2018, The Linux Foundation. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 and
> + * only 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.
> + */
Can we get the SPDX tags here please?
> +
> +#include <linux/clk.h>
clk-provider.h?
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +#include "clk-alpha-pll.h"
#include "clk-regmap.h"
> +
> +#define VCO(a, b, c) { \
> + .val = a,\
> + .min_freq = b,\
> + .max_freq = c,\
> +}
Can this define go into whatever PLL header file defines the struct?
> +
> +#define DIV_2_INDEX 0
> +#define PLL_INDEX 1
> +#define ACD_INDEX 2
> +#define ALT_INDEX 3
> +
> +static const u8 prim_pll_regs[PLL_OFF_MAX_REGS] = {
> + [PLL_OFF_L_VAL] = 0x04,
> + [PLL_OFF_ALPHA_VAL] = 0x08,
> + [PLL_OFF_USER_CTL] = 0x10,
> + [PLL_OFF_CONFIG_CTL] = 0x18,
> + [PLL_OFF_CONFIG_CTL_U] = 0x1C,
Please use lowercase hex throughout. Consistency is key!
> + [PLL_OFF_TEST_CTL] = 0x20,
> + [PLL_OFF_TEST_CTL_U] = 0x24,
> + [PLL_OFF_STATUS] = 0x28,
> +};
> +
> +static const u8 alt_pll_regs[PLL_OFF_MAX_REGS] = {
> + [PLL_OFF_L_VAL] = 0x04,
> + [PLL_OFF_ALPHA_VAL] = 0x08,
> + [PLL_OFF_ALPHA_VAL_U] = 0x0c,
> + [PLL_OFF_USER_CTL] = 0x10,
> + [PLL_OFF_USER_CTL_U] = 0x14,
> + [PLL_OFF_CONFIG_CTL] = 0x18,
> + [PLL_OFF_TEST_CTL] = 0x20,
> + [PLL_OFF_TEST_CTL_U] = 0x24,
> + [PLL_OFF_STATUS] = 0x28,
> +};
> +
> +/* PLLs */
> +
> +static const struct alpha_pll_config hfpll_config = {
> + .l = 60,
> + .config_ctl_val = 0x200d4828,
> + .config_ctl_hi_val = 0x006,
> + .pre_div_mask = BIT(12),
> + .post_div_mask = 0x3 << 8,
> + .main_output_mask = BIT(0),
> + .early_output_mask = BIT(3),
> +};
> +
> +static struct clk_alpha_pll perfcl_pll = {
> + .offset = 0x80000,
> + .regs = prim_pll_regs,
> + .flags = SUPPORTS_DYNAMIC_UPDATE | SUPPORTS_FSM_MODE,
> + .clkr.hw.init = &(struct clk_init_data){
> + .name = "perfcl_pll",
> + .parent_names = (const char *[]){ "xo" },
> + .num_parents = 1,
> + .ops = &clk_alpha_pll_huayra_ops,
> + },
> +};
> +
> +static struct clk_alpha_pll pwrcl_pll = {
> + .offset = 0x0,
> + .regs = prim_pll_regs,
> + .flags = SUPPORTS_DYNAMIC_UPDATE | SUPPORTS_FSM_MODE,
> + .clkr.hw.init = &(struct clk_init_data){
> + .name = "pwrcl_pll",
> + .parent_names = (const char *[]){ "xo" },
> + .num_parents = 1,
> + .ops = &clk_alpha_pll_huayra_ops,
> + },
> +};
> +
> +static const struct pll_vco alt_pll_vco_modes[] = {
> + VCO(3, 250000000, 500000000),
> + VCO(2, 500000000, 750000000),
> + VCO(1, 750000000, 1000000000),
> + VCO(0, 1000000000, 2150400000),
> +};
> +
> +static const struct alpha_pll_config altpll_config = {
> + .l = 16,
> + .vco_val = 0x3 << 20,
> + .vco_mask = 0x3 << 20,
> + .config_ctl_val = 0x4001051b,
> + .post_div_mask = 0x3 << 8,
> + .post_div_val = 0x1,
> + .main_output_mask = BIT(0),
> + .early_output_mask = BIT(3),
> +};
> +
> +static struct clk_alpha_pll perfcl_alt_pll = {
> + .offset = 0x80100,
> + .regs = alt_pll_regs,
> + .vco_table = alt_pll_vco_modes,
> + .num_vco = ARRAY_SIZE(alt_pll_vco_modes),
> + .flags = SUPPORTS_OFFLINE_REQ | SUPPORTS_FSM_MODE,
> + .clkr.hw.init = &(struct clk_init_data) {
> + .name = "perfcl_alt_pll",
> + .parent_names = (const char *[]){ "xo" },
> + .num_parents = 1,
> + .ops = &clk_alpha_pll_hwfsm_ops,
> + },
> +};
> +
> +static struct clk_alpha_pll pwrcl_alt_pll = {
> + .offset = 0x100,
> + .regs = alt_pll_regs,
> + .vco_table = alt_pll_vco_modes,
> + .num_vco = ARRAY_SIZE(alt_pll_vco_modes),
> + .flags = SUPPORTS_OFFLINE_REQ | SUPPORTS_FSM_MODE,
> + .clkr.hw.init = &(struct clk_init_data) {
> + .name = "pwrcl_alt_pll",
> + .parent_names = (const char *[]){ "xo" },
> + .num_parents = 1,
> + .ops = &clk_alpha_pll_hwfsm_ops,
> + },
> +};
> +
> +/* Mux'es */
> +
> +struct clk_cpu_8996_mux {
> + u32 reg;
> + u32 shift;
u8 shift?
> + u32 width;
u8 width?
> + struct clk_hw *pll;
> + struct clk_regmap clkr;
> +};
> +
> +static inline
> +struct clk_cpu_8996_mux *to_clk_cpu_8996_mux_hw(struct clk_hw *hw)
> +{
> + return container_of(to_clk_regmap(hw), struct clk_cpu_8996_mux, clkr);
> +}
> +
> +static u8 clk_cpu_8996_mux_get_parent(struct clk_hw *hw)
> +{
> + unsigned int val;
> + struct clk_regmap *clkr = to_clk_regmap(hw);
> + struct clk_cpu_8996_mux *cpuclk = to_clk_cpu_8996_mux_hw(hw);
> + unsigned int mask = GENMASK(cpuclk->width - 1, 0);
> +
> + regmap_read(clkr->regmap, cpuclk->reg, &val);
> +
> + val >>= cpuclk->shift;
> + val &= mask;
> +
> + return val;
return val & mask;
> +}
> +
> +static int clk_cpu_8996_mux_set_parent(struct clk_hw *hw, u8 index)
> +{
> + unsigned int val;
u32 val?
> + struct clk_regmap *clkr = to_clk_regmap(hw);
> + struct clk_cpu_8996_mux *cpuclk = to_clk_cpu_8996_mux_hw(hw);
> + unsigned int mask = GENMASK(cpuclk->width + cpuclk->shift - 1,
> + cpuclk->shift);
> +
> + val = index;
> + val <<= cpuclk->shift;
> +
> + return regmap_update_bits(clkr->regmap, cpuclk->reg, mask, val);
> +}
> +
> +static int
> +clk_cpu_8996_mux_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
> +{
> + struct clk_cpu_8996_mux *cpuclk = to_clk_cpu_8996_mux_hw(hw);
> + struct clk_hw *parent = cpuclk->pll;
> +
> + if (!cpuclk->pll)
> + return -EINVAL;
Does this happen?
> +
> + req->best_parent_rate = clk_hw_round_rate(parent, req->rate);
> + req->best_parent_hw = parent;
Is the parent index always the same? Perhaps just call
clk_hw_get_parent_by_index() then instead of adding a pointer to the
clk_cpu_8996_mux.
> +
> + return 0;
> +}
> +
> +const struct clk_ops clk_cpu_8996_mux_ops = {
> + .set_parent = clk_cpu_8996_mux_set_parent,
> + .get_parent = clk_cpu_8996_mux_get_parent,
> + .determine_rate = clk_cpu_8996_mux_determine_rate,
> +};
[...]
> +
> +static struct clk_cpu_8996_mux pwrcl_pmux = {
> + .reg = 0x40,
> + .shift = 0,
> + .width = 2,
> + .pll = &pwrcl_pll.clkr.hw,
> + .clkr.hw.init = &(struct clk_init_data) {
> + .name = "pwrcl_pmux",
> + .parent_names = (const char *[]){
> + "pwrcl_smux",
> + "pwrcl_pll",
> + "pwrcl_pll_acd",
> + "pwrcl_alt_pll",
> + },
> + .num_parents = 4,
> + .ops = &clk_cpu_8996_mux_ops,
> + .flags = CLK_SET_RATE_PARENT | CLK_IS_CRITICAL,
> + },
> +};
> +
> +static struct clk_cpu_8996_mux perfcl_pmux = {
> + .reg = 0x80040,
> + .shift = 0,
> + .width = 2,
> + .pll = &perfcl_pll.clkr.hw,
> + .clkr.hw.init = &(struct clk_init_data) {
> + .name = "perfcl_pmux",
> + .parent_names = (const char *[]){
> + "perfcl_smux",
> + "perfcl_pll",
> + "perfcl_pll_acd",
> + "perfcl_alt_pll",
> + },
> + .num_parents = 4,
> + .ops = &clk_cpu_8996_mux_ops,
> + .flags = CLK_SET_RATE_PARENT | CLK_IS_CRITICAL,
Not sure CLK_IS_CRITICAL is the right mode. Perhaps CLK_IGNORE_UNUSED
for now? We don't want to force XO to stay on forever here.
> + },
> +};
> +
> +static const struct regmap_config cpu_msm8996_regmap_config = {
> + .reg_bits = 32,
> + .reg_stride = 4,
> + .val_bits = 32,
> + .max_register = 0x80210,
> + .fast_io = true,
> + .val_format_endian = REGMAP_ENDIAN_LITTLE,
> +};
> +
> +static const struct of_device_id match_table[] = {
Move this next to driver structure and give it a more specific name.
> + { .compatible = "qcom-msm8996-apcc" },
Bad compatible? Should be qcom,msm8996-apcc?
> + {}
> +};
> +
> +struct clk_regmap *clks[] = {
> + /* PLLs */
> + &perfcl_pll.clkr,
> + &pwrcl_pll.clkr,
> + &perfcl_alt_pll.clkr,
> + &pwrcl_alt_pll.clkr,
> + /* MUXs */
> + &perfcl_smux.clkr,
> + &pwrcl_smux.clkr,
> + &perfcl_pmux.clkr,
> + &pwrcl_pmux.clkr,
Please drop useless comments inside this array.
> +};
> +
> +struct clk_hw_clks {
> + unsigned int num;
> + struct clk_hw *hws[];
> +};
Please just NULL terminate the list of clk_hw pointers, or keep the
size around instead.
> +
> +static int
> +qcom_cpu_clk_msm8996_register_clks(struct device *dev, struct clk_hw_clks *hws,
> + struct regmap *regmap)
> +{
> + int i, ret;
> +
> + hws->hws[0] = clk_hw_register_fixed_factor(dev, "perfcl_pll_main",
> + "perfcl_pll",
> + CLK_SET_RATE_PARENT, 1, 2);
> + perfcl_smux.pll = hws->hws[0];
> +
> + hws->hws[1] = clk_hw_register_fixed_factor(dev, "pwrcl_pll_main",
> + "pwrcl_pll",
> + CLK_SET_RATE_PARENT, 1, 2);
> + pwrcl_smux.pll = hws->hws[1];
> +
> + hws->num = 2;
Maybe just open code the fixed factor clk registration? Then the
devm_clk_hw_register() function can be used on those static structs to
make removal simpler.
> +
> + for (i = 0; i < ARRAY_SIZE(clks); i++) {
> + ret = devm_clk_register_regmap(dev, clks[i]);
> + if (ret)
> + return ret;
> + }
> +
> + clk_alpha_pll_configure(&perfcl_pll, regmap, &hfpll_config);
> + clk_alpha_pll_configure(&pwrcl_pll, regmap, &hfpll_config);
> + clk_alpha_pll_configure(&perfcl_alt_pll, regmap, &altpll_config);
> + clk_alpha_pll_configure(&pwrcl_alt_pll, regmap, &altpll_config);
> +
> + return ret;
> +}
> +
> +static int qcom_cpu_clk_msm8996_driver_probe(struct platform_device *pdev)
> +{
> + int ret;
> + void __iomem *base;
> + struct resource *res;
> + struct regmap *regmap_cpu;
Just call it regmap please.
> + struct clk_hw_clks *hws;
> + struct clk_hw_onecell_data *data;
> + struct device *dev = &pdev->dev;
> + struct device_node *node = dev->of_node;
> +
> + data = devm_kzalloc(dev, sizeof(*data) + 2 * sizeof(struct clk_hw *),
> + GFP_KERNEL);
> + if (!data)
> + return -ENOMEM;
> +
> + hws = devm_kzalloc(dev, sizeof(*hws) + 2 * sizeof(struct clk_hw *),
> + GFP_KERNEL);
> + if (!hws)
> + return -ENOMEM;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + base = devm_ioremap_resource(dev, res);
> + if (IS_ERR(base))
> + return PTR_ERR(base);
> +
> + regmap_cpu = devm_regmap_init_mmio(dev, base,
> + &cpu_msm8996_regmap_config);
> + if (IS_ERR(regmap_cpu))
> + return PTR_ERR(regmap_cpu);
> +
> + ret = qcom_cpu_clk_msm8996_register_clks(dev, hws, regmap_cpu);
> + if (ret)
> + return ret;
> +
> + data->hws[0] = &pwrcl_pmux.clkr.hw;
> + data->hws[1] = &perfcl_pmux.clkr.hw;
> +
> + data->num = 2;
> +
> + platform_set_drvdata(pdev, hws);
> +
> + return of_clk_add_hw_provider(node, of_clk_hw_onecell_get, data);
> +}
> +
> +static int qcom_cpu_clk_msm8996_driver_remove(struct platform_device *pdev)
> +{
> + int i;
> + struct device *dev = &pdev->dev;
> + struct clk_hw_clks *hws = platform_get_drvdata(pdev);
> +
> + for (i = 0; i < hws->num; i++)
> + clk_hw_unregister_fixed_rate(hws->hws[i]);
> +
> + of_clk_del_provider(dev->of_node);
Use devm_of_clk_add_hw_provider() instead.
> +
> + return 0;
> +}
> +
> +static struct platform_driver qcom_cpu_clk_msm8996_driver = {
> + .probe = qcom_cpu_clk_msm8996_driver_probe,
> + .remove = qcom_cpu_clk_msm8996_driver_remove,
> + .driver = {
> + .name = "qcom-msm8996-apcc",
> + .of_match_table = match_table,
> + },
> +};
> +
> +module_platform_driver(qcom_cpu_clk_msm8996_driver);
> +
> +MODULE_ALIAS("platform:msm8996-apcc");
> +MODULE_DESCRIPTION("QCOM MSM8996 CPU clock Driver");
Not sure why Driver is capitalized and clock is not.
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