Re: [PATCH v6 3/5] mmc: dw_mmc: add support for hi3798mv200

From: Yang Xiwen
Date: Tue Feb 27 2024 - 19:58:47 EST

On 2/27/2024 11:16 PM, Ulf Hansson wrote:
> On Wed, 21 Feb 2024 at 13:45, Yang Xiwen via B4 Relay
> <devnull+forbidden405.outlook.com@xxxxxxxxxx> wrote:
>>
>> From: Yang Xiwen <forbidden405@xxxxxxxxxxx>
>>
>> Add support for Hi3798MV200 specific extension.
>>
>> Signed-off-by: Yang Xiwen <forbidden405@xxxxxxxxxxx>
>> ---
>> drivers/mmc/host/Kconfig | 9 ++
>> drivers/mmc/host/Makefile | 1 +
>> drivers/mmc/host/dw_mmc-hi3798mv200.c | 239 ++++++++++++++++++++++++++++++++++
>> 3 files changed, 249 insertions(+)
>>
>> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
>> index 81f2c4e05287..aebc587f77a7 100644
>> --- a/drivers/mmc/host/Kconfig
>> +++ b/drivers/mmc/host/Kconfig
>> @@ -798,6 +798,15 @@ config MMC_DW_HI3798CV200
>> Synopsys DesignWare Memory Card Interface driver. Select this option
>> for platforms based on HiSilicon Hi3798CV200 SoC.
>>
>> +config MMC_DW_HI3798MV200
>> + tristate "Hi3798MV200 specific extensions for Synopsys DW Memory Card Interface"
>> + depends on MMC_DW
>> + select MMC_DW_PLTFM
>> + help
>> + This selects support for HiSilicon Hi3798MV200 SoC specific extensions to the
>> + Synopsys DesignWare Memory Card Interface driver. Select this option
>> + for platforms based on HiSilicon Hi3798MV200 SoC.
>> +
>> config MMC_DW_K3
>> tristate "K3 specific extensions for Synopsys DW Memory Card Interface"
>> depends on MMC_DW
>> diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
>> index d0be4465f3ec..f53f86d200ac 100644
>> --- a/drivers/mmc/host/Makefile
>> +++ b/drivers/mmc/host/Makefile
>> @@ -51,6 +51,7 @@ obj-$(CONFIG_MMC_DW_PLTFM) += dw_mmc-pltfm.o
>> obj-$(CONFIG_MMC_DW_BLUEFIELD) += dw_mmc-bluefield.o
>> obj-$(CONFIG_MMC_DW_EXYNOS) += dw_mmc-exynos.o
>> obj-$(CONFIG_MMC_DW_HI3798CV200) += dw_mmc-hi3798cv200.o
>> +obj-$(CONFIG_MMC_DW_HI3798MV200) += dw_mmc-hi3798mv200.o
>> obj-$(CONFIG_MMC_DW_K3) += dw_mmc-k3.o
>> obj-$(CONFIG_MMC_DW_PCI) += dw_mmc-pci.o
>> obj-$(CONFIG_MMC_DW_ROCKCHIP) += dw_mmc-rockchip.o
>> diff --git a/drivers/mmc/host/dw_mmc-hi3798mv200.c b/drivers/mmc/host/dw_mmc-hi3798mv200.c
>> new file mode 100644
>> index 000000000000..73aaa21040ea
>> --- /dev/null
>> +++ b/drivers/mmc/host/dw_mmc-hi3798mv200.c
>> @@ -0,0 +1,239 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Modified from dw_mmc-hi3798cv200.c
>> + *
>> + * Copyright (c) 2024 Yang Xiwen <forbidden405@xxxxxxxxxxx>
>> + * Copyright (c) 2018 HiSilicon Technologies Co., Ltd.
>> + */
>> +
>> +#include <linux/clk.h>
>> +#include <linux/mfd/syscon.h>
>> +#include <linux/mmc/host.h>
>> +#include <linux/module.h>
>> +#include <linux/of_address.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/regmap.h>
>> +
>> +#include "dw_mmc.h"
>> +#include "dw_mmc-pltfm.h"
>> +
>> +#define SDMMC_TUNING_CTRL 0x118
>> +#define SDMMC_TUNING_FIND_EDGE BIT(5)
>> +
>> +#define ALL_INT_CLR 0x1ffff
>> +
>> +/* DLL ctrl reg */
>> +#define SAP_DLL_CTRL_DLLMODE BIT(16)
>> +
>> +struct dw_mci_hi3798mv200_priv {
>> + struct clk *sample_clk;
>> + struct clk *drive_clk;
>> + struct regmap *crg_reg;
>> + u32 sap_dll_offset;
>> + struct mmc_clk_phase_map phase_map;
>> +};
>> +
>> +static void dw_mci_hi3798mv200_set_ios(struct dw_mci *host, struct mmc_ios *ios)
>> +{
>> + struct dw_mci_hi3798mv200_priv *priv = host->priv;
>> + struct mmc_clk_phase phase = priv->phase_map.phase[ios->timing];
>> + u32 val;
>> +
>> + val = mci_readl(host, ENABLE_SHIFT);
>> + if (ios->timing == MMC_TIMING_MMC_DDR52
>> + || ios->timing == MMC_TIMING_UHS_DDR50)
>> + val |= SDMMC_ENABLE_PHASE;
>> + else
>> + val &= ~SDMMC_ENABLE_PHASE;
>> + mci_writel(host, ENABLE_SHIFT, val);
>> +
>> + val = mci_readl(host, DDR_REG);
>> + if (ios->timing == MMC_TIMING_MMC_HS400)
>> + val |= SDMMC_DDR_HS400;
>> + else
>> + val &= ~SDMMC_DDR_HS400;
>> + mci_writel(host, DDR_REG, val);
>> +
>> + if (clk_set_rate(host->ciu_clk, ios->clock))
>> + dev_warn(host->dev, "Failed to set rate to %u\n", ios->clock);
>> + else
>> + // CLK_MUX_ROUND_NEAREST is enabled for this clock
>> + // The actual clock rate is not what we setted, but a rounded value
>> + // so we should get the rate once again
>
> Please use proper comments sections (/* .... */) and not "//".
>
>> + host->bus_hz = clk_get_rate(host->ciu_clk);
>> +
>> + if (phase.valid) {
>> + clk_set_phase(priv->drive_clk, phase.out_deg);
>> + clk_set_phase(priv->sample_clk, phase.in_deg);
>> + } else {
>> + dev_warn(host->dev,
>> + "The phase entry for timing mode %d is missing in device tree.\n",
>> + ios->timing);
>> + }
>> +}
>> +
>> +static inline int dw_mci_hi3798mv200_enable_tuning(struct dw_mci_slot *slot)
>> +{
>> + struct dw_mci_hi3798mv200_priv *priv = slot->host->priv;
>> +
>> + return regmap_clear_bits(priv->crg_reg, priv->sap_dll_offset, SAP_DLL_CTRL_DLLMODE);
>> +}
>> +
>> +static inline int dw_mci_hi3798mv200_disable_tuning(struct dw_mci_slot *slot)
>> +{
>> + struct dw_mci_hi3798mv200_priv *priv = slot->host->priv;
>> +
>> + return regmap_set_bits(priv->crg_reg, priv->sap_dll_offset, SAP_DLL_CTRL_DLLMODE);
>> +}
>> +
>> +static int dw_mci_hi3798mv200_execute_tuning_mix_mode(struct dw_mci_slot *slot,
>> + u32 opcode)
>> +{
>> + static const int degrees[] = { 0, 45, 90, 135, 180, 225, 270, 315 };
>> + struct dw_mci *host = slot->host;
>> + struct dw_mci_hi3798mv200_priv *priv = host->priv;
>> + int raise_point = -1, fall_point = -1;
>> + int err, prev_err = -1;
>> + int found = 0;
>> + int regval;
>> + int i;
>> + int ret;
>> +
>> + // enable tuning
>
> Looks like a redundant comment, please drop it.
>
>> + ret = dw_mci_hi3798mv200_enable_tuning(slot);
>> + if (ret < 0)
>> + return ret;
>
> A newline here would improve the readability I think.
>
>> + for (i = 0; i < ARRAY_SIZE(degrees); i++) {
>> + clk_set_phase(priv->sample_clk, degrees[i]);
>> + mci_writel(host, RINTSTS, ALL_INT_CLR);
>> +
>> + err = mmc_send_tuning(slot->mmc, opcode, NULL);
>> + if (!err) {
>> + regval = mci_readl(host, TUNING_CTRL);
>> + if (regval & SDMMC_TUNING_FIND_EDGE)
>> + err = 1;
>> + else
>> + found = 1;
>> + };
>> +
>> + if (i > 0) {
>> + if (err && !prev_err)
>> + fall_point = i - 1;
>> + if (!err && prev_err)
>> + raise_point = i;
>> + }
>> +
>> + if (raise_point != -1 && fall_point != -1)
>> + goto tuning_out;
>> +
>> + prev_err = err;
>> + err = 0;
>> + }
>> +
>> +tuning_out:
>> + ret = dw_mci_hi3798mv200_disable_tuning(slot);
>> + if (ret < 0)
>> + return ret;
>> + if (found) {
>> + if (raise_point == -1)
>> + raise_point = 0;
>> + if (fall_point == -1)
>> + fall_point = ARRAY_SIZE(degrees) - 1;
>> + if (fall_point < raise_point) {
>> + if ((raise_point + fall_point) >
>> + (ARRAY_SIZE(degrees) - 1))
>> + i = fall_point / 2;
>> + else
>> + i = (raise_point + ARRAY_SIZE(degrees) - 1) / 2;
>> + } else {
>> + i = (raise_point + fall_point) / 2;
>> + }
>> +
>> + // use the same phase table for both HS200 and HS400
>
> Don't use "//" for comments.
>
>> + priv->phase_map.phase[MMC_TIMING_MMC_HS200].in_deg = degrees[i];
>> + priv->phase_map.phase[MMC_TIMING_MMC_HS400].in_deg = degrees[i];
>> +
>> + clk_set_phase(priv->sample_clk, degrees[i]);
>> + dev_dbg(host->dev, "Tuning clk_sample[%d, %d], set[%d]\n",
>> + raise_point, fall_point, degrees[i]);
>> + err = 0;
>> + } else {
>> + dev_err(host->dev, "No valid clk_sample shift! use default\n");
>> + err = -EINVAL;
>> + }
>> +
>> + mci_writel(host, RINTSTS, ALL_INT_CLR);
>> + return err;
>
> The entire code in dw_mci_hi3798mv200_execute_tuning_mix_mode() looks
> rather messy to me. A lot of variables are being used, set and reset
> from everywhere.
>
> Would you mind having a closer look and try to improve it a bit, so it
> becomes easier to follow what is going on?

That might because the code here is modified from dw-mmc_hi3798cv200.c.
And That file is already a mess. I'll try to improve it soon.

>
>> +}
>> +
>> +static int dw_mci_hi3798mv200_init(struct dw_mci *host)
>> +{
>> + struct dw_mci_hi3798mv200_priv *priv;
>> + struct device_node *np = host->dev->of_node;
>> + int ret;
>> +
>> + priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL);
>> + if (!priv)
>> + return -ENOMEM;
>> +
>> + mmc_of_parse_clk_phase(host->dev, &priv->phase_map);
>> +
>> + priv->sample_clk = devm_clk_get_enabled(host->dev, "ciu-sample");
>> + if (IS_ERR(priv->sample_clk))
>> + return dev_err_probe(host->dev, PTR_ERR(priv->sample_clk),
>> + "failed to get enabled ciu-sample clock\n");
>> +
>> + priv->drive_clk = devm_clk_get_enabled(host->dev, "ciu-drive");
>> + if (IS_ERR(priv->drive_clk))
>> + return dev_err_probe(host->dev, PTR_ERR(priv->drive_clk),
>> + "failed to get enabled ciu-drive clock\n");
>> +
>> + priv->crg_reg = syscon_regmap_lookup_by_phandle(np, "hisilicon,sap-dll-reg");
>> + if (IS_ERR(priv->crg_reg))
>> + return dev_err_probe(host->dev, PTR_ERR(priv->crg_reg),
>> + "failed to get CRG reg\n");
>> +
>> + ret = of_property_read_u32_index(np, "hisilicon,sap-dll-reg", 1, &priv->sap_dll_offset);
>> + if (ret)
>> + return dev_err_probe(host->dev, ret, "failed to get sample DLL register offset\n");
>> +
>> + host->priv = priv;
>> + return 0;
>> +}
>> +
>> +static const struct dw_mci_drv_data hi3798mv200_data = {
>> + .common_caps = MMC_CAP_CMD23,
>> + .init = dw_mci_hi3798mv200_init,
>> + .set_ios = dw_mci_hi3798mv200_set_ios,
>> + .execute_tuning = dw_mci_hi3798mv200_execute_tuning_mix_mode,
>> +};
>> +
>> +static const struct of_device_id dw_mci_hi3798mv200_match[] = {
>> + { .compatible = "hisilicon,hi3798mv200-dw-mshc" },
>> + {},
>> +};
>> +
>> +static int dw_mci_hi3798mv200_probe(struct platform_device *pdev)
>> +{
>> + return dw_mci_pltfm_register(pdev, &hi3798mv200_data);
>> +}
>> +
>> +static void dw_mci_hi3798mv200_remove(struct platform_device *pdev)
>> +{
>> + dw_mci_pltfm_remove(pdev);
>> +}
>> +
>> +MODULE_DEVICE_TABLE(of, dw_mci_hi3798mv200_match);
>> +static struct platform_driver dw_mci_hi3798mv200_driver = {
>> + .probe = dw_mci_hi3798mv200_probe,
>> + .remove_new = dw_mci_hi3798mv200_remove,
>> + .driver = {
>> + .name = "dwmmc_hi3798mv200",
>> + .probe_type = PROBE_PREFER_ASYNCHRONOUS,
>> + .of_match_table = dw_mci_hi3798mv200_match,
>> + },
>> +};
>> +module_platform_driver(dw_mci_hi3798mv200_driver);
>> +
>> +MODULE_DESCRIPTION("HiSilicon Hi3798MV200 Specific DW-MSHC Driver Extension");
>> +MODULE_LICENSE("GPL");
>>
>
> Kind regards
> Uffe

--
Best regards,
Yang Xiwen