Re: [PATCH 4/4] clk: qcom: Add graphics clock controller driver for SDM845

From: Amit Nischal
Date: Thu Jul 12 2018 - 08:38:20 EST


On 2018-07-09 11:37, Stephen Boyd wrote:
Quoting Amit Nischal (2018-06-06 04:41:48)
diff --git a/drivers/clk/qcom/gpucc-sdm845.c b/drivers/clk/qcom/gpucc-sdm845.c
new file mode 100644
index 0000000..81f8926
--- /dev/null
+++ b/drivers/clk/qcom/gpucc-sdm845.c
@@ -0,0 +1,441 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include <dt-bindings/clock/qcom,gpucc-sdm845.h>
+
+#include "common.h"
+#include "clk-alpha-pll.h"
+#include "clk-branch.h"
+#include "clk-pll.h"
+#include "clk-rcg.h"
+#include "clk-regmap.h"
+#include "gdsc.h"
+
+#define CX_GMU_CBCR_SLEEP_MASK 0xf
+#define CX_GMU_CBCR_SLEEP_SHIFT 4
+#define CX_GMU_CBCR_WAKE_MASK 0xf
+#define CX_GMU_CBCR_WAKE_SHIFT 8
+#define CLK_DIS_WAIT_SHIFT 12
+#define CLK_DIS_WAIT_MASK (0xf << CLK_DIS_WAIT_SHIFT)
+
+#define F(f, s, h, m, n) { (f), (s), (2 * (h) - 1), (m), (n) }

This should be removed and series can depend on Taniya's patch.


Yes sure. I will do the required change and will submit the next
patch series.

+
+enum {
+ P_BI_TCXO,
+ P_CORE_BI_PLL_TEST_SE,
+ P_GPLL0_OUT_MAIN,
+ P_GPLL0_OUT_MAIN_DIV,
[...]
+ .regs = clk_alpha_pll_regs[CLK_ALPHA_PLL_TYPE_FABIA],
+ .clkr = {
+ .hw.init = &(struct clk_init_data){
+ .name = "gpu_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 },
+ {},

Drop the trailing comma, it's a sentinel presumably.


Will fix this in the next patch series.

+};
+
+static struct clk_alpha_pll_postdiv gpu_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 = "gpu_cc_pll0_out_even",
+ .parent_names = (const char *[]){ "gpu_cc_pll0" },
+ .num_parents = 1,
+ .flags = CLK_SET_RATE_PARENT,
+ .ops = &clk_alpha_pll_postdiv_fabia_ops,
+ },
+};
+
+static struct clk_alpha_pll gpu_cc_pll1 = {
+ .offset = 0x100,
+ .regs = clk_alpha_pll_regs[CLK_ALPHA_PLL_TYPE_FABIA],
+ .clkr = {
+ .hw.init = &(struct clk_init_data){
+ .name = "gpu_cc_pll1",
+ .parent_names = (const char *[]){ "bi_tcxo" },
+ .num_parents = 1,
+ .ops = &clk_alpha_pll_fabia_ops,
+ },
+ },
+};
+
+static const struct freq_tbl ftbl_gpu_cc_gmu_clk_src[] = {
+ F(19200000, P_BI_TCXO, 1, 0, 0),
+ F(200000000, P_GPLL0_OUT_MAIN_DIV, 1.5, 0, 0),
+ F(500000000, P_GPU_CC_PLL1_OUT_MAIN, 1, 0, 0),
+ { }
+};
+
+static struct clk_rcg2 gpu_cc_gmu_clk_src = {
+ .cmd_rcgr = 0x1120,
+ .mnd_width = 0,
+ .hid_width = 5,
+ .parent_map = gpu_cc_parent_map_0,
+ .freq_tbl = ftbl_gpu_cc_gmu_clk_src,
+ .clkr.hw.init = &(struct clk_init_data){
+ .name = "gpu_cc_gmu_clk_src",
+ .parent_names = gpu_cc_parent_names_0,
+ .num_parents = 6,
+ .ops = &clk_rcg2_shared_ops,
+ },
+};
+
+static const struct freq_tbl ftbl_gpu_cc_gx_gfx3d_clk_src[] = {
+ F(180000000, P_GPU_CC_PLL0_OUT_EVEN, 2, 0, 0),
+ F(257000000, P_GPU_CC_PLL0_OUT_EVEN, 2, 0, 0),
+ F(342000000, P_GPU_CC_PLL0_OUT_EVEN, 2, 0, 0),
+ F(414000000, P_GPU_CC_PLL0_OUT_EVEN, 2, 0, 0),
+ F(520000000, P_GPU_CC_PLL0_OUT_EVEN, 2, 0, 0),
+ F(596000000, P_GPU_CC_PLL0_OUT_EVEN, 2, 0, 0),
+ F(675000000, P_GPU_CC_PLL0_OUT_EVEN, 2, 0, 0),
+ F(710000000, P_GPU_CC_PLL0_OUT_EVEN, 2, 0, 0),

Do we really need to encode anything here in this table? Why can't we
have clk_ops that hardcode this clk to be a div-2 that passes the
frequency up to the parent source? Then this frequency table doesn't
need to be here at all, and can live in DT as an OPP table used by the
GPU driver.


Thanks for the suggestion.
I will address the same in the next patch series where
"clk_rcg2_gfx3d_determine_rate" op will always return the best parent as
âGPU_CC_PLL0_OUT_EVENâ and best_parent rate equal to twice of the requested rate.
This will eliminate the need of frequency table.

+ { }
+};
+
+static struct clk_rcg2 gpu_cc_gx_gfx3d_clk_src = {
+ .cmd_rcgr = 0x101c,
+ .mnd_width = 0,
+ .hid_width = 5,
+ .parent_map = gpu_cc_parent_map_1,
+ .freq_tbl = ftbl_gpu_cc_gx_gfx3d_clk_src,
+ .clkr.hw.init = &(struct clk_init_data){
+ .name = "gpu_cc_gx_gfx3d_clk_src",
+ .parent_names = gpu_cc_parent_names_1,
+ .num_parents = 7,
+ .flags = CLK_SET_RATE_PARENT,
+ .ops = &clk_rcg2_gfx3d_ops,
[...]
+static struct clk_branch gpu_cc_cx_gmu_clk = {
+ .halt_reg = 0x1098,
+ .halt_check = BRANCH_HALT,
+ .clkr = {
+ .enable_reg = 0x1098,
+ .enable_mask = BIT(0),
+ .hw.init = &(struct clk_init_data){
+ .name = "gpu_cc_cx_gmu_clk",
+ .parent_names = (const char *[]){
+ "gpu_cc_gmu_clk_src",
+ },
+ .num_parents = 1,
+ .flags = CLK_SET_RATE_PARENT,
+ .ops = &clk_branch2_ops,
+ },
+ },
+};
+
+static struct clk_branch gpu_cc_cx_snoc_dvm_clk = {
+ .halt_reg = 0x108c,
+ .halt_check = BRANCH_HALT,
+ .clkr = {
+ .enable_reg = 0x108c,
+ .enable_mask = BIT(0),
+ .hw.init = &(struct clk_init_data){
+ .name = "gpu_cc_cx_snoc_dvm_clk",
+ .ops = &clk_branch2_ops,
+ },
+ },
+};
+
+static struct clk_branch gpu_cc_cxo_clk = {

This isn't always on and marked critical?

No, this clock is not marked critical as GCC driver doesn't
control this clock.


+ .halt_reg = 0x109c,
+ .halt_check = BRANCH_HALT,
+ .clkr = {
+ .enable_reg = 0x109c,
+ .enable_mask = BIT(0),
+ .hw.init = &(struct clk_init_data){
+ .name = "gpu_cc_cxo_clk",
+ .ops = &clk_branch2_ops,
+ },
+ },
[...]
+
+static struct gdsc gpu_cx_gdsc = {
+ .gdscr = 0x106c,
+ .gds_hw_ctrl = 0x1540,
+ .pd = {
+ .name = "gpu_cx_gdsc",
+ },
+ .pwrsts = PWRSTS_OFF_ON,
+ .flags = VOTABLE,
+};
+
+static struct gdsc gpu_gx_gdsc = {
+ .gdscr = 0x100c,
+ .clamp_io_ctrl = 0x1508,
+ .pd = {
+ .name = "gpu_gx_gdsc",
+ },
+ .clk_hws = {
+ &gpu_cc_gx_gfx3d_clk_src.clkr.hw,

Hmm alright. So basically the core GPU power domain needs the wrapper
domain (CX) to be powered on and clocking for GX to work? Let's talk
about it in the other patch so I can understand more.


Yes, to turn on the GPU GX GDSC it requires below to be in ON state first.
1. GPU_CX_GDSC
2. ROOT clock GFX3D clock source.

+ },
+ .clk_count = 1,
+ .pwrsts = PWRSTS_OFF_ON,
+ .flags = CLAMP_IO | AON_RESET | POLL_CFG_GDSCR,
+};
+
[...]
+
+static int gpu_cc_sdm845_probe(struct platform_device *pdev)
+{
+ struct regmap *regmap;
+ unsigned int value, mask;
+
+ regmap = qcom_cc_map(pdev, &gpu_cc_sdm845_desc);
+ if (IS_ERR(regmap))
+ return PTR_ERR(regmap);
+
+ clk_fabia_pll_configure(&gpu_cc_pll0, regmap, &gpu_cc_pll0_config);
+ clk_fabia_pll_configure(&gpu_cc_pll1, regmap, &gpu_cc_pll1_config);
+
+ /* Configure gpu_cc_cx_gmu_clk with recommended wakeup/sleep settings */
+ mask = CX_GMU_CBCR_WAKE_MASK << CX_GMU_CBCR_WAKE_SHIFT;
+ mask |= CX_GMU_CBCR_SLEEP_MASK << CX_GMU_CBCR_SLEEP_SHIFT;
+ value = 0xf << CX_GMU_CBCR_WAKE_SHIFT | 0xf << CX_GMU_CBCR_SLEEP_SHIFT;
+ regmap_update_bits(regmap, 0x1098, mask, value);
+
+ /* Configure clk_dis_wait for for gpu_cx_gdsc */

s/for //


I will address this in the next patch series.

+ regmap_update_bits(regmap, 0x106c, CLK_DIS_WAIT_MASK,
+ (8 << CLK_DIS_WAIT_SHIFT));

Remove extra parenthesis.

Yes sure, I will fix this in the next patch series.

+
+ return qcom_cc_really_probe(pdev, &gpu_cc_sdm845_desc, regmap);
+}
+
[...]
+
+MODULE_LICENSE("GPL v2");

MODULE_DESCRIPTION?

I will add the module description in the next patch series.