[PATCH v2 1/3] mmc: hi6220-dwmmc: handle clocks and resets if CONFIG_CLK and CONFIG_DM_RESET enabled

[Yang Xiwen]

On 4/3/2024 8:39 AM, Jaehoon Chung wrote:
> Hi,
>
> On 2/1/24 23:05, Yang Xiwen via B4 Relay wrote:
>> From: Yang Xiwen <forbidden405 at outlook.com>
>>
>> This can avoid hardcoding a clock rate in driver. Also can enable the
>> clocks and deassert the resets if the pre-bootloader does not do this
>> for us.
>>
>> Currently only enabled for Hi3798MV200.
>>
>> Signed-off-by: Yang Xiwen <forbidden405 at outlook.com>
>> ---
>>   drivers/mmc/hi6220_dw_mmc.c | 61 ++++++++++++++++++++++++++++++++++++++++++++-
>>   1 file changed, 60 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/mmc/hi6220_dw_mmc.c b/drivers/mmc/hi6220_dw_mmc.c
>> index 71962cd47e..a4b8072976 100644
>> --- a/drivers/mmc/hi6220_dw_mmc.c
>> +++ b/drivers/mmc/hi6220_dw_mmc.c
>> @@ -5,15 +5,24 @@
>>    */
>>   
>>   #include <common.h>
>> +#include <clk.h>
>>   #include <dm.h>
>>   #include <dwmmc.h>
>>   #include <errno.h>
>>   #include <fdtdec.h>
>>   #include <malloc.h>
>> +#include <reset.h>
>>   #include <asm/global_data.h>
>> +#include <dm/device_compat.h>
>>   
>>   DECLARE_GLOBAL_DATA_PTR;
>>   
>> +enum hi6220_dwmmc_clk_type {
>> +	HI6220_DWMMC_CLK_BIU,
>> +	HI6220_DWMMC_CLK_CIU,
>> +	HI6220_DWMMC_CLK_CNT,
>> +};
>> +
>>   struct hi6220_dwmmc_plat {
>>   	struct mmc_config cfg;
>>   	struct mmc mmc;
>> @@ -21,6 +30,8 @@ struct hi6220_dwmmc_plat {
>>   
>>   struct hi6220_dwmmc_priv_data {
>>   	struct dwmci_host host;
>> +	struct clk *clks[HI6220_DWMMC_CLK_CNT];
>> +	struct reset_ctl_bulk rsts;
>>   };
>>   
>>   struct hisi_mmc_data {
>> @@ -32,7 +43,29 @@ static int hi6220_dwmmc_of_to_plat(struct udevice *dev)
>>   {
>>   	struct hi6220_dwmmc_priv_data *priv = dev_get_priv(dev);
>>   	struct dwmci_host *host = &priv->host;
>> +	int ret;
> If CONFIG_CLK and DM_RESET aren't enabled, this value is a dead code.
> It also needs to initialize.


I think a alternative solution is replacing the if stmt below with some 
`#ifdef`s just like some unittests code. So we can mask variable `ret' 
out if it's not used However, this seems not favored by checkpatch.pl.


>
>>   
>> +	if (CONFIG_IS_ENABLED(CLK) && CONFIG_IS_ENABLED(DM_RESET)) {
>> +		priv->clks[HI6220_DWMMC_CLK_BIU] = devm_clk_get(dev, "biu");
>> +		if (IS_ERR(priv->clks[HI6220_DWMMC_CLK_BIU])) {
>> +			ret = PTR_ERR(priv->clks[HI6220_DWMMC_CLK_BIU]);
>> +			dev_err(dev, "Failed to get BIU clock(ret = %d).\n", ret);
>> +			return log_msg_ret("clk", ret);
>> +		}
>> +
>> +		priv->clks[HI6220_DWMMC_CLK_CIU] = devm_clk_get(dev, "ciu");
>> +		if (IS_ERR(priv->clks[HI6220_DWMMC_CLK_CIU])) {
>> +			ret = PTR_ERR(priv->clks[HI6220_DWMMC_CLK_CIU]);
>> +			dev_err(dev, "Failed to get CIU clock(ret = %d).\n", ret);
>> +			return log_msg_ret("clk", ret);
>> +		}
>> +
>> +		ret = reset_get_bulk(dev, &priv->rsts);
>> +		if (ret) {
>> +			dev_err(dev, "Failed to get resets(ret = %d)", ret);
>> +			return log_msg_ret("rst", ret);
>> +		}
>> +	}
>>   	host->name = dev->name;
>>   	host->ioaddr = dev_read_addr_ptr(dev);
>>   	host->buswidth = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev),
>> @@ -56,11 +89,37 @@ static int hi6220_dwmmc_probe(struct udevice *dev)
>>   	struct hi6220_dwmmc_priv_data *priv = dev_get_priv(dev);
>>   	struct dwmci_host *host = &priv->host;
>>   	struct hisi_mmc_data *mmc_data;
>> +	int ret;
> Ditto.
>
>
> Best Regards,
> Jaehoon Chung
>
>>   
>>   	mmc_data = (struct hisi_mmc_data *)dev_get_driver_data(dev);
>>   
>> -	/* Use default bus speed due to absence of clk driver */
>>   	host->bus_hz = mmc_data->clock;
>> +	if (CONFIG_IS_ENABLED(CLK) && CONFIG_IS_ENABLED(DM_RESET)) {
>> +		ret = clk_prepare_enable(priv->clks[HI6220_DWMMC_CLK_BIU]);
>> +		if (ret) {
>> +			dev_err(dev, "Failed to enable biu clock(ret = %d).\n", ret);
>> +			return log_msg_ret("clk", ret);
>> +		}
>> +
>> +		ret = clk_prepare_enable(priv->clks[HI6220_DWMMC_CLK_CIU]);
>> +		if (ret) {
>> +			dev_err(dev, "Failed to enable ciu clock(ret = %d).\n", ret);
>> +			return log_msg_ret("clk", ret);
>> +		}
>> +
>> +		ret = reset_deassert_bulk(&priv->rsts);
>> +		if (ret) {
>> +			dev_err(dev, "Failed to deassert resets(ret = %d).\n", ret);
>> +			return log_msg_ret("rst", ret);
>> +		}
>> +
>> +		host->bus_hz = clk_get_rate(priv->clks[HI6220_DWMMC_CLK_CIU]);
>> +		if (host->bus_hz <= 0) {
>> +			dev_err(dev, "Failed to get ciu clock rate(ret = %d).\n", ret);
>> +			return log_msg_ret("clk", ret);
>> +		}
>> +	}
>> +	dev_dbg(dev, "bus clock rate: %d.\n", host->bus_hz);
>>   
>>   	dwmci_setup_cfg(&plat->cfg, host, host->bus_hz, 400000);
>>   	host->mmc = &plat->mmc;


-- 
Regards,
Yang Xiwen