Re: [PATCH 2/2] clk: qcom: gcc: Add global clock controller driver for QCS404

Taniya Das
2018-10-06T17:49:38Z

Hello Vinod,

On 10/3/2018 11:51 AM, Vinod wrote:
> Hi Stephen,
>
> Thanks for the comments,
>
> On 01-10-18, 10:19, Stephen Boyd wrote:
>> Quoting Vinod Koul (2018-09-21 11:59:36)
>>> From: Shefali Jain <shefjain@codeaurora.org>
>>>
>>> Add the clocks supported in global clock controller which clock the
>>> peripherals like BLSPs, SDCC, USB, MDSS etc. Register all the clocks
>>> to the clock framework for the clients to be able to request for them.
>>>
>>> Signed-off-by: Shefali Jain <shefjain@codeaurora.org>
>>> Signed-off-by: Taniya Das <tdas@codeaurora.org>
>>> Co-developed-by: Taniya Das <tdas@codeaurora.org>
>>> Signed-off-by: Anu Ramanathan <anur@codeaurora.org>
>>> [rebase and tidyup for upstream]
>>
>> Who did the tidying?
>
> both of us :)
>
>>> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
>>> Signed-off-by: Vinod Koul <vkoul@kernel.org>
>>> ---
>>> - reg : shall contain base register location and length
>>> diff --git a/drivers/clk/qcom/Kconfig b/drivers/clk/qcom/Kconfig
>>> index 064768699fe7..529d84cc7503 100644
>>> --- a/drivers/clk/qcom/Kconfig
>>> +++ b/drivers/clk/qcom/Kconfig
>>> @@ -235,6 +235,14 @@ config MSM_GCC_8998
>>> Say Y if you want to use peripheral devices such as UART, SPI,
>>> i2c, USB, UFS, SD/eMMC, PCIe, etc.
>>>
>>> +config QCS_GCC_404
>>> + tristate "QCS404 Global Clock Controller"
>>> + depends on COMMON_CLK_QCOM
>>> + help
>>> + Support for the global clock controller on QCS404 devices.
>>> + Say Y if you want to use peripheral devices such as UART, SPI, I2C,
>>> + USB, SD/eMMC, PCIe, etc.
>>
>> It seems to include multimedia display clks and ethernet? Maybe include
>> those too.
>
> Sure will add
>
>>> +#include <linux/kernel.h>
>>> +#include <linux/platform_device.h>
>>> +#include <linux/module.h>
>>> +#include <linux/of.h>
>>> +#include <linux/clk.h>
>>
>> Please don't include this.
>
> OK will check if this is required, any reason for not including this?
>
>>> +/* 930MHz configuration */
>>> +static const struct alpha_pll_config gpll3_config = {
>>> + .l = 48,
>>> + .alpha = 0x0,
>>> + .alpha_en_mask = BIT(24),
>>> + .post_div_mask = 0xf << 8,
>>> + .post_div_val = 0x1 << 8,
>>> + .vco_mask = 0x3 << 20,
>>> + .main_output_mask = 0x1,
>>> + .config_ctl_val = 0x4001055b,
>>> +};
>>> +
>>> +static struct pll_vco gpll3_vco[] = {
>>
>> const?
>
> sure
>
>>> +static struct clk_branch gcc_pwm1_xo512_clk = {
>>> + .halt_reg = 0x49004,
>>> + .halt_check = BRANCH_HALT,
>>> + .clkr = {
>>> + .enable_reg = 0x49004,
>>> + .enable_mask = BIT(0),
>>> + .hw.init = &(struct clk_init_data){
>>> + .name = "gcc_pwm1_xo512_clk",
>>> + .ops = &clk_branch2_ops,
>>
>> Do these pwm clks have a parent clk of the XO?
>
> Yes they do
>

We do not need to specify the parent here.

>>> + [GCC_USB_HS_PHY_CFG_AHB_CLK] = &gcc_usb_hs_phy_cfg_ahb_clk.clkr,
>>> + [GCC_USB_HS_SYSTEM_CLK] = &gcc_usb_hs_system_clk.clkr,
>>> + [GFX3D_CLK_SRC] = &gfx3d_clk_src.clkr,
>>> + [GP1_CLK_SRC] = &gp1_clk_src.clkr,
>>
>> Why are some of these missing GCC_ prefix?
>
> will add..
>

These clocks in HW plans do not have GCC prefixed, so it better to leave
them as they are represented in the HW.

>>> +static int gcc_qcs404_probe(struct platform_device *pdev)
>>> +{
>>> + struct regmap *regmap;
>>> + int ret;
>>> +
>>> + ret = qcom_cc_register_board_clk(&pdev->dev,
>>> + "xo_board", "cxo", 19200000);
>>
>> You shouldn't need to do this. This function is for transitioning DT
>> that doesn't have the board clk in DT to something the driver wants to
>> use, in this case "cxo". So you can either register a fixed factor 1/1
>> clk to do the translation between board and cxo names, or use xo_board
>> as the parent of things that can take crystal.
>
> Okay will modify this. If I go about using xo_board as parent, I would
> need to register that right? FWIW I see the same thing done in gcc-msm8916
>

As Stephen suggested it should be defined in DT till we use the
clk-smd-rpm.c.

>>
>>> + if (ret)
>>> + return ret;
>>> +
>>> + regmap = qcom_cc_map(pdev, &gcc_qcs404_desc);
>>> + if (IS_ERR(regmap))
>>> + return PTR_ERR(regmap);
>>> +
>>> + clk_alpha_pll_configure(&gpll3_out_main, regmap, &gpll3_config);
>>> + clk_set_rate(apss_ahb_clk_src.clkr.hw.clk, 19200000);
>>
>> use assigned clock rates from DT please.
>
> ok
>
>>> + clk_prepare_enable(apss_ahb_clk_src.clkr.hw.clk);
>>> + clk_prepare_enable(gpll0_ao_out_main.clkr.hw.clk);
>>
>> And these should be marked as critical clocks.
>
> Okay and how do we go about doing that?
>
>>> +#define GCC_USB2A_PHY_SLEEP_CLK 89
>>> +#define GCC_USB30_MASTER_CLK 90
>>> +#define GCC_USB30_MOCK_UTMI_CLK 91
>>> +#define gcc_usb30_sleep_clk 92
>>> +#define gcc_usb3_phy_aux_clk 93
>>> +#define gcc_usb3_phy_pipe_clk 94
>>> +#define gcc_usb_hs_phy_cfg_ahb_clk 95
>>> +#define gcc_usb_hs_system_clk 96
>>> +#define gfx3d_clk_src 97
>>> +#define gp1_clk_src 98
>>> +#define gp2_clk_src 99
>>> +#define gp3_clk_src 100
>>> +#define gpll0_out_main 101
>>> +#define gpll1_out_main 102
>>> +#define gpll3_out_main 103
>>> +#define gpll4_out_main 104
>>> +#define hdmi_app_clk_src 105
>>> +#define hdmi_pclk_clk_src 106
>>> +#define mdp_clk_src 107
>>> +#define pcie_0_aux_clk_src 108
>>> +#define pcie_0_pipe_clk_src 109
>>> +#define pclk0_clk_src 110
>>> +#define pdm2_clk_src 111
>>> +#define sdcc1_apps_clk_src 112
>>> +#define sdcc1_ice_core_clk_src 113
>>> +#define sdcc2_apps_clk_src 114
>>> +#define usb20_mock_utmi_clk_src 115
>>> +#define usb30_master_clk_src 116
>>> +#define usb30_mock_utmi_clk_src 117
>>> +#define usb3_phy_aux_clk_src 118
>>> +#define usb_hs_system_clk_src 119
>>> +#define gpll0_ao_clk_src 120
>>> +#define wcnss_m_clk 121
>>> +#define gcc_usb_hs_inactivity_timers_clk 122
>>
>> Please capitalize all these macros.
>
> Will do
>
>>> +#define GCC_GENI_IR_BCR 0
>>> +#define GCC_USB_HS_BCR 1
>>> +#define GCC_USB2_HS_PHY_ONLY_BCR 2
>>> +#define GCC_QUSB2_PHY_BCR 3
>>> +#define GCC_USB_HS_PHY_CFG_AHB_BCR 4
>>> +#define GCC_USB2A_PHY_BCR 5
>>> +#define GCC_USB3_PHY_BCR 6
>>> +#define GCC_USB_30_BCR 7
>>> +#define GCC_USB3PHY_PHY_BCR 8
>>> +#define GCC_PCIE_0_BCR 9
>>> +#define GCC_PCIE_0_PHY_BCR 10
>>> +#define GCC_PCIE_0_LINK_DOWN_BCR 11
>>> +#define GCC_PCIEPHY_0_PHY_BCR 12
>>> +#define GCC_EMAC_BCR 13
>>
>> No GDSCs? Ok.
>
> Downstream doesn't seem to have one, will recheck specs.
>

Downstream uses different way to handle GDSC, there are 2 GDSCs which
have to be added 1 for MDSS and 1 OXILI_GX.

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