Re: [PATCH 2/2] clk: qcom: Add camera clock controller driver for SDM845

From: Stephen Boyd
Date: Thu Jul 26 2018 - 13:22:35 EST


Quoting Amit Nischal (2018-07-23 04:26:33)
> diff --git a/drivers/clk/qcom/camcc-sdm845.c b/drivers/clk/qcom/camcc-sdm845.c
> new file mode 100644
> index 0000000..61e5ec2
> --- /dev/null
> +++ b/drivers/clk/qcom/camcc-sdm845.c
> @@ -0,0 +1,1736 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2018, The Linux Foundation. All rights reserved.
> + */
> +
> +#include <linux/clk.h>

Is this include used?

> +#include <linux/clk-provider.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +#include <dt-bindings/clock/qcom,camcc-sdm845.h>
> +
> +#include "common.h"
> +#include "clk-alpha-pll.h"
> +#include "clk-branch.h"
> +#include "clk-rcg.h"
> +#include "clk-regmap.h"
> +#include "gdsc.h"
> +
> +enum {
> + P_BI_TCXO,
> + P_CAM_CC_PLL0_OUT_EVEN,
> + P_CAM_CC_PLL1_OUT_EVEN,
> + P_CAM_CC_PLL2_OUT_EVEN,
> + P_CAM_CC_PLL3_OUT_EVEN,
> + P_CORE_BI_PLL_TEST_SE,
> +};
> +
> +static const struct parent_map cam_cc_parent_map_0[] = {
> + { P_BI_TCXO, 0 },
> + { P_CAM_CC_PLL2_OUT_EVEN, 1 },
> + { P_CAM_CC_PLL1_OUT_EVEN, 2 },
> + { P_CAM_CC_PLL3_OUT_EVEN, 5 },
> + { P_CAM_CC_PLL0_OUT_EVEN, 6 },
> + { P_CORE_BI_PLL_TEST_SE, 7 },
> +};
> +
> +static const char * const cam_cc_parent_names_0[] = {
> + "bi_tcxo",
> + "cam_cc_pll2_out_even",
> + "cam_cc_pll1_out_even",
> + "cam_cc_pll3_out_even",
> + "cam_cc_pll0_out_even",
> + "core_bi_pll_test_se",
> +};
> +
> +static struct clk_alpha_pll cam_cc_pll0 = {
> + .offset = 0x0,
> + .regs = clk_alpha_pll_regs[CLK_ALPHA_PLL_TYPE_FABIA],
> + .clkr = {
> + .hw.init = &(struct clk_init_data){
> + .name = "cam_cc_pll0",
> + .parent_names = (const char *[]){ "bi_tcxo" },
> + .num_parents = 1,
> + .ops = &clk_alpha_pll_fabia_ops,
> + },
> + },
> +};
> +
> +static const struct clk_div_table post_div_table_fabia_even[] = {
> + { 0x0, 1 },
> + { 0x1, 2 },
> + { }
> +};
> +
> +static struct clk_alpha_pll_postdiv cam_cc_pll0_out_even = {
> + .offset = 0x0,
> + .post_div_shift = 8,
> + .post_div_table = post_div_table_fabia_even,
> + .num_post_div = ARRAY_SIZE(post_div_table_fabia_even),
> + .width = 4,
> + .regs = clk_alpha_pll_regs[CLK_ALPHA_PLL_TYPE_FABIA],
> + .clkr.hw.init = &(struct clk_init_data){
> + .name = "cam_cc_pll0_out_even",
> + .parent_names = (const char *[]){ "cam_cc_pll0" },
> + .num_parents = 1,
> + .ops = &clk_alpha_pll_postdiv_fabia_ops,
> + },
> +};
> +
> +static struct clk_alpha_pll cam_cc_pll1 = {
> + .offset = 0x1000,
> + .regs = clk_alpha_pll_regs[CLK_ALPHA_PLL_TYPE_FABIA],
> + .clkr = {
> + .hw.init = &(struct clk_init_data){
> + .name = "cam_cc_pll1",
> + .parent_names = (const char *[]){ "bi_tcxo" },
> + .num_parents = 1,
> + .ops = &clk_alpha_pll_fabia_ops,
> + },
> + },
> +};
> +
> +static struct clk_alpha_pll_postdiv cam_cc_pll1_out_even = {
> + .offset = 0x1000,
> + .post_div_shift = 8,
> + .post_div_table = post_div_table_fabia_even,
> + .num_post_div = ARRAY_SIZE(post_div_table_fabia_even),
> + .width = 4,
> + .regs = clk_alpha_pll_regs[CLK_ALPHA_PLL_TYPE_FABIA],
> + .clkr.hw.init = &(struct clk_init_data){
> + .name = "cam_cc_pll1_out_even",
> + .parent_names = (const char *[]){ "cam_cc_pll1" },
> + .num_parents = 1,
> + .ops = &clk_alpha_pll_postdiv_fabia_ops,
> + },
> +};
> +
> +static struct clk_alpha_pll cam_cc_pll2 = {
> + .offset = 0x2000,
> + .regs = clk_alpha_pll_regs[CLK_ALPHA_PLL_TYPE_FABIA],
> + .clkr = {
> + .hw.init = &(struct clk_init_data){
> + .name = "cam_cc_pll2",
> + .parent_names = (const char *[]){ "bi_tcxo" },
> + .num_parents = 1,
> + .ops = &clk_alpha_pll_fabia_ops,
> + },
> + },
> +};
> +
> +static struct clk_alpha_pll_postdiv cam_cc_pll2_out_even = {
> + .offset = 0x2000,
> + .post_div_shift = 8,
> + .post_div_table = post_div_table_fabia_even,
> + .num_post_div = ARRAY_SIZE(post_div_table_fabia_even),
> + .width = 4,
> + .regs = clk_alpha_pll_regs[CLK_ALPHA_PLL_TYPE_FABIA],
> + .clkr.hw.init = &(struct clk_init_data){
> + .name = "cam_cc_pll2_out_even",
> + .parent_names = (const char *[]){ "cam_cc_pll2" },
> + .num_parents = 1,
> + .ops = &clk_alpha_pll_postdiv_fabia_ops,
> + },
> +};
> +
> +static struct clk_alpha_pll cam_cc_pll3 = {
> + .offset = 0x3000,
> + .regs = clk_alpha_pll_regs[CLK_ALPHA_PLL_TYPE_FABIA],
> + .clkr = {
> + .hw.init = &(struct clk_init_data){
> + .name = "cam_cc_pll3",
> + .parent_names = (const char *[]){ "bi_tcxo" },
> + .num_parents = 1,
> + .ops = &clk_alpha_pll_fabia_ops,
> + },
> + },
> +};
> +
> +static struct clk_alpha_pll_postdiv cam_cc_pll3_out_even = {
> + .offset = 0x3000,
> + .post_div_shift = 8,
> + .post_div_table = post_div_table_fabia_even,
> + .num_post_div = ARRAY_SIZE(post_div_table_fabia_even),
> + .width = 4,
> + .regs = clk_alpha_pll_regs[CLK_ALPHA_PLL_TYPE_FABIA],
> + .clkr.hw.init = &(struct clk_init_data){
> + .name = "cam_cc_pll3_out_even",
> + .parent_names = (const char *[]){ "cam_cc_pll3" },
> + .num_parents = 1,
> + .ops = &clk_alpha_pll_postdiv_fabia_ops,
> + },
> +};
> +
> +static const struct freq_tbl ftbl_cam_cc_bps_clk_src[] = {
> + F(19200000, P_BI_TCXO, 1, 0, 0),
> + F(100000000, P_CAM_CC_PLL0_OUT_EVEN, 6, 0, 0),
> + F(200000000, P_CAM_CC_PLL0_OUT_EVEN, 3, 0, 0),
> + F(404000000, P_CAM_CC_PLL1_OUT_EVEN, 2, 0, 0),
> + F(480000000, P_CAM_CC_PLL2_OUT_EVEN, 1, 0, 0),
> + F(600000000, P_CAM_CC_PLL0_OUT_EVEN, 1, 0, 0),
> + { }
> +};
> +
> +static struct clk_rcg2 cam_cc_bps_clk_src = {
> + .cmd_rcgr = 0x600c,
> + .mnd_width = 0,
> + .hid_width = 5,
> + .parent_map = cam_cc_parent_map_0,
> + .freq_tbl = ftbl_cam_cc_bps_clk_src,
> + .clkr.hw.init = &(struct clk_init_data){
> + .name = "cam_cc_bps_clk_src",
> + .parent_names = cam_cc_parent_names_0,
> + .num_parents = 6,
> + .flags = CLK_SET_RATE_PARENT,
> + .ops = &clk_rcg2_shared_ops,

Why are shared ops used in this driver?

> + },
> +};
> +
> +static const struct freq_tbl ftbl_cam_cc_cci_clk_src[] = {
> + F(19200000, P_BI_TCXO, 1, 0, 0),
> + F(37500000, P_CAM_CC_PLL0_OUT_EVEN, 16, 0, 0),
> + F(50000000, P_CAM_CC_PLL0_OUT_EVEN, 12, 0, 0),
> + F(100000000, P_CAM_CC_PLL0_OUT_EVEN, 6, 0, 0),
> + { }
> +};
> +
[...]
> + .clkr.hw.init = &(struct clk_init_data){
> + .name = "cam_cc_mclk0_clk_src",
> + .parent_names = cam_cc_parent_names_0,
> + .num_parents = 6,
> + .flags = CLK_SET_RATE_PARENT,
> + .ops = &clk_rcg2_ops,
> + },
> +};
> +
> +static struct clk_rcg2 cam_cc_mclk1_clk_src = {
> + .cmd_rcgr = 0x4024,
> + .mnd_width = 8,
> + .hid_width = 5,
> + .parent_map = cam_cc_parent_map_0,
> + .freq_tbl = ftbl_cam_cc_mclk0_clk_src,
> + .clkr.hw.init = &(struct clk_init_data){
> + .name = "cam_cc_mclk1_clk_src",
> + .parent_names = cam_cc_parent_names_0,
> + .num_parents = 6,
> + .flags = CLK_SET_RATE_PARENT,
> + .ops = &clk_rcg2_ops,
> + },
> +};
> +
> +static struct clk_rcg2 cam_cc_mclk2_clk_src = {
> + .cmd_rcgr = 0x4044,
> + .mnd_width = 8,
> + .hid_width = 5,
> + .parent_map = cam_cc_parent_map_0,
> + .freq_tbl = ftbl_cam_cc_mclk0_clk_src,
> + .clkr.hw.init = &(struct clk_init_data){
> + .name = "cam_cc_mclk2_clk_src",
> + .parent_names = cam_cc_parent_names_0,
> + .num_parents = 6,
> + .flags = CLK_SET_RATE_PARENT,
> + .ops = &clk_rcg2_ops,
> + },
> +};
> +
> +static struct clk_rcg2 cam_cc_mclk3_clk_src = {
> + .cmd_rcgr = 0x4064,
> + .mnd_width = 8,
> + .hid_width = 5,
> + .parent_map = cam_cc_parent_map_0,
> + .freq_tbl = ftbl_cam_cc_mclk0_clk_src,
> + .clkr.hw.init = &(struct clk_init_data){
> + .name = "cam_cc_mclk3_clk_src",
> + .parent_names = cam_cc_parent_names_0,
> + .num_parents = 6,
> + .flags = CLK_SET_RATE_PARENT,
> + .ops = &clk_rcg2_ops,
> + },
> +};
> +
> +static const struct freq_tbl ftbl_cam_cc_slow_ahb_clk_src[] = {
> + F(19200000, P_BI_TCXO, 1, 0, 0),
> + F(60000000, P_CAM_CC_PLL0_OUT_EVEN, 10, 0, 0),
> + F(66666667, P_CAM_CC_PLL0_OUT_EVEN, 9, 0, 0),
> + F(73846154, P_CAM_CC_PLL2_OUT_EVEN, 6.5, 0, 0),
> + F(80000000, P_CAM_CC_PLL2_OUT_EVEN, 6, 0, 0),
> + { }
> +};
> +
> +static struct clk_rcg2 cam_cc_slow_ahb_clk_src = {
> + .cmd_rcgr = 0x6054,
> + .mnd_width = 0,
> + .hid_width = 5,
> + .parent_map = cam_cc_parent_map_0,
> + .freq_tbl = ftbl_cam_cc_slow_ahb_clk_src,
> + .clkr.hw.init = &(struct clk_init_data){
> + .name = "cam_cc_slow_ahb_clk_src",
> + .parent_names = cam_cc_parent_names_0,
> + .num_parents = 6,
> + .flags = CLK_SET_RATE_PARENT,

Is CLK_SET_RATE_PARENT intentionally set on these RCGs so that they can
reconfigure the PLL frequency? Wouldn't that be a fixed rate PLL
frequency?

> + .ops = &clk_rcg2_ops,
> + },
> +};
> +
[...]
> +
> +static int cam_cc_sdm845_probe(struct platform_device *pdev)
> +{
> + struct regmap *regmap;
> + struct alpha_pll_config cam_cc_pll_config = { };
> +
> + regmap = qcom_cc_map(pdev, &cam_cc_sdm845_desc);
> + if (IS_ERR(regmap))
> + return PTR_ERR(regmap);
> +
> + cam_cc_pll_config.l = 0x1f,
> + cam_cc_pll_config.alpha = 0x4000,

Replace these commas with semicolons.

> + clk_fabia_pll_configure(&cam_cc_pll0, regmap, &cam_cc_pll_config);
> +
> + cam_cc_pll_config.l = 0x2a,
> + cam_cc_pll_config.alpha = 0x1556,
> + clk_fabia_pll_configure(&cam_cc_pll1, regmap, &cam_cc_pll_config);

All over this function.

Can you also add comments in the commit text and code describing why
oddities like CLK_SET_RATE_PARENT on RCGs and shared rcg ops is used?