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

["Jaehoon Chung" <jh80.chung@samsung.com>]

Hi,

> -----Original Message-----
> From: Yang Xiwen <forbidden405@outlook.com>
> Sent: Wednesday, April 3, 2024 10:16 AM
> To: Jaehoon Chung <jh80.chung@samsung.com>; Peng Fan <peng.fan@nxp.com>
> Cc: u-boot@lists.denx.de
> Subject: Re: [PATCH v2 1/3] mmc: hi6220-dwmmc: handle clocks and resets if CONFIG_CLK and
> CONFIG_DM_RESET enabled
> 
> 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@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@outlook.com>

Reviewed-by: Jaehoon Chung <jh80.chung@samsung.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.

It's not a critical thing. If possible to change more generic, I will change them.
Thanks!

Best Regards,
Jaehoon Chung

> 
> 
> >
> >>
> >> +	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