Re: [PATCH RESEND v2 1/2] mtd: rawnand: meson: discard the common MMC sub clock framework

[Liang Yang <liang.yang@xxxxxxxxxxx>]

Hello Jerome,

On 2022/2/28 19:28, Jerome Brunet wrote:
> [ EXTERNAL EMAIL ]
>
>
> On Thu 17 Feb 2022 at 14:33, Liang Yang <liang.yang@xxxxxxxxxxx> wrote:
>
> > EMMC and NAND have the same clock control register named 'SD_EMMC_CLOCK' which is
> > defined in EMMC port internally. bit0~5 of 'SD_EMMC_CLOCK' is the divider and
> > bit6~7 is the mux for fix pll and xtal.A common MMC and NAND sub-clock has been
> > implemented and can be used by the eMMC and NAND controller (which are mutually
> > exclusive anyway). Let's use this new clock.
> >
> > Signed-off-by: Liang Yang <liang.yang@xxxxxxxxxxx>
> > ---
> >   drivers/mtd/nand/raw/meson_nand.c | 107 +++++++++++++++++-------------
> >   1 file changed, 61 insertions(+), 46 deletions(-)
> >
> > diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c
> > index ac3be92872d0..c5b892d38ea0 100644
> > --- a/drivers/mtd/nand/raw/meson_nand.c
> > +++ b/drivers/mtd/nand/raw/meson_nand.c
> > @@ -10,6 +10,7 @@
> >   #include <linux/dma-mapping.h>
> >   #include <linux/interrupt.h>
> >   #include <linux/clk.h>
> > +#include <linux/clk-provider.h>
> >   #include <linux/mtd/rawnand.h>
> >   #include <linux/mtd/mtd.h>
> >   #include <linux/mfd/syscon.h>
> > @@ -19,6 +20,7 @@
> >   #include <linux/iopoll.h>
> >   #include <linux/of.h>
> >   #include <linux/of_device.h>
> > +#include <linux/of_address.h>
> >   #include <linux/sched/task_stack.h>
> >   
> >   #define NFC_REG_CMD		0x00
> > @@ -104,6 +106,9 @@
> >   
> >   #define PER_INFO_BYTE		8
> >   
> > +#define CLK_DIV_SHIFT		0
> > +#define CLK_DIV_WIDTH		6
> > +
> >   struct meson_nfc_nand_chip {
> >   	struct list_head node;
> >   	struct nand_chip nand;
> > @@ -151,15 +156,15 @@ struct meson_nfc {
> >   	struct nand_controller controller;
> >   	struct clk *core_clk;
> >   	struct clk *device_clk;
> > -	struct clk *phase_tx;
> > -	struct clk *phase_rx;
> > +	struct clk *nand_clk;
> > +	struct clk_divider nand_divider;
> >   
> >   	unsigned long clk_rate;
> >   	u32 bus_timing;
> >   
> >   	struct device *dev;
> >   	void __iomem *reg_base;
> > -	struct regmap *reg_clk;
> > +	void __iomem *sd_emmc_clock;
> >   	struct completion completion;
> >   	struct list_head chips;
> >   	const struct meson_nfc_data *data;
> > @@ -988,6 +993,8 @@ static const struct mtd_ooblayout_ops meson_ooblayout_ops = {
> >   static int meson_nfc_clk_init(struct meson_nfc *nfc)
> >   {
> >   	int ret;
> > +	struct clk_init_data init = {0};
> > +	struct clk_parent_data nfc_divider_parent_data[1];
> >   
> >   	/* request core clock */
> >   	nfc->core_clk = devm_clk_get(nfc->dev, "core");
> > @@ -1002,21 +1009,26 @@ static int meson_nfc_clk_init(struct meson_nfc *nfc)
> >   		return PTR_ERR(nfc->device_clk);
> >   	}
> >   
> > -	nfc->phase_tx = devm_clk_get(nfc->dev, "tx");
> > -	if (IS_ERR(nfc->phase_tx)) {
> > -		dev_err(nfc->dev, "failed to get TX clk\n");
> > -		return PTR_ERR(nfc->phase_tx);
> > -	}
> > -
> > -	nfc->phase_rx = devm_clk_get(nfc->dev, "rx");
> > -	if (IS_ERR(nfc->phase_rx)) {
> > -		dev_err(nfc->dev, "failed to get RX clk\n");
> > -		return PTR_ERR(nfc->phase_rx);
> > -	}
> > +	init.name = devm_kstrdup(nfc->dev, "nfc#div", GFP_KERNEL);
> > +	init.ops = &clk_divider_ops;
> > +	nfc_divider_parent_data[0].fw_name = __clk_get_name(nfc->device_clk);
>
> This is broken.
> __clk_get_name() gives the actual global name of the clock
> "fw_name" is the DT name which allows to find the index on the clock
>
> > From the DT doc, the fw_name is either 'core' or 'device'
>
> I don't think any clock would have such a name so I don't think this can
> actually work. Did you actually test this ?
> Indeed, it can't work. i have tried it.
so let us get solved by nfc_divider_parent_data[0].fw_name = "device" or 
previous parent_names? thanks.

> > +	init.parent_data = nfc_divider_parent_data;
> > +	init.num_parents = 1;
> > +	nfc->nand_divider.reg = nfc->sd_emmc_clock;
> > +	nfc->nand_divider.shift = CLK_DIV_SHIFT;
> > +	nfc->nand_divider.width = CLK_DIV_WIDTH;
> > +	nfc->nand_divider.hw.init = &init;
> > +	nfc->nand_divider.flags = CLK_DIVIDER_ONE_BASED |
> > +				  CLK_DIVIDER_ROUND_CLOSEST |
> > +				  CLK_DIVIDER_ALLOW_ZERO;
> > +
> > +	nfc->nand_clk = devm_clk_register(nfc->dev, &nfc->nand_divider.hw);
> > +	if (IS_ERR(nfc->nand_clk))
> > +		return PTR_ERR(nfc->nand_clk);
> >   
> >   	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
> > -	regmap_update_bits(nfc->reg_clk,
> > -			   0, CLK_SELECT_NAND, CLK_SELECT_NAND);
> > +	writel(CLK_SELECT_NAND | readl(nfc->sd_emmc_clock),
> > +	       nfc->sd_emmc_clock);
> >   
> >   	ret = clk_prepare_enable(nfc->core_clk);
> >   	if (ret) {
> > @@ -1030,29 +1042,21 @@ static int meson_nfc_clk_init(struct meson_nfc *nfc)
> >   		goto err_device_clk;
> >   	}
> >   
> > -	ret = clk_prepare_enable(nfc->phase_tx);
> > -	if (ret) {
> > -		dev_err(nfc->dev, "failed to enable TX clock\n");
> > -		goto err_phase_tx;
> > -	}
> > -
> > -	ret = clk_prepare_enable(nfc->phase_rx);
> > +	ret = clk_prepare_enable(nfc->nand_clk);
> >   	if (ret) {
> > -		dev_err(nfc->dev, "failed to enable RX clock\n");
> > -		goto err_phase_rx;
> > +		dev_err(nfc->dev, "pre enable NFC divider fail\n");
> > +		goto err_nand_clk;
> >   	}
> >   
> >   	ret = clk_set_rate(nfc->device_clk, 24000000);
> >   	if (ret)
> > -		goto err_disable_rx;
> > +		goto err_disable_clk;
> >   
> >   	return 0;
> >   
> > -err_disable_rx:
> > -	clk_disable_unprepare(nfc->phase_rx);
> > -err_phase_rx:
> > -	clk_disable_unprepare(nfc->phase_tx);
> > -err_phase_tx:
> > +err_disable_clk:
> > +	clk_disable_unprepare(nfc->nand_clk);
> > +err_nand_clk:
> >   	clk_disable_unprepare(nfc->device_clk);
> >   err_device_clk:
> >   	clk_disable_unprepare(nfc->core_clk);
> > @@ -1061,8 +1065,7 @@ static int meson_nfc_clk_init(struct meson_nfc *nfc)
> >   
> >   static void meson_nfc_disable_clk(struct meson_nfc *nfc)
> >   {
> > -	clk_disable_unprepare(nfc->phase_rx);
> > -	clk_disable_unprepare(nfc->phase_tx);
> > +	clk_disable_unprepare(nfc->nand_clk);
> >   	clk_disable_unprepare(nfc->device_clk);
> >   	clk_disable_unprepare(nfc->core_clk);
> >   }
> > @@ -1370,11 +1373,31 @@ static const struct of_device_id meson_nfc_id_table[] = {
> >   };
> >   MODULE_DEVICE_TABLE(of, meson_nfc_id_table);
> >   
> > +static int meson_nfc_reg_resource(struct device *dev, struct meson_nfc *nfc)
> > +{
> > +	struct resource res;
> > +	void __iomem *base[2];
> > +	struct device_node *node = dev->of_node;
> > +	int i;
> > +
> > +	for (i = 0; i < 2; i++) {
> > +		if (of_address_to_resource(node, i, &res))
> > +			return -ENOENT;
> > +
> > +		base[i] = devm_ioremap_resource(dev, &res);
> > +		if (IS_ERR(base))
> > +			return PTR_ERR(base);
> > +	}
> > +	nfc->reg_base = base[0];
> > +	nfc->sd_emmc_clock = base[1];
> > +
>
> There is no reason to make a separate function for this.
>
> Please name your ressource and claim them properly instead of interating
> on them.
>
>
> > +	return 0;
> > +}
> > +
> >   static int meson_nfc_probe(struct platform_device *pdev)
> >   {
> >   	struct device *dev = &pdev->dev;
> >   	struct meson_nfc *nfc;
> > -	struct resource *res;
> >   	int ret, irq;
> >   
> >   	nfc = devm_kzalloc(dev, sizeof(*nfc), GFP_KERNEL);
> > @@ -1388,20 +1411,12 @@ static int meson_nfc_probe(struct platform_device *pdev)
> >   	nand_controller_init(&nfc->controller);
> >   	INIT_LIST_HEAD(&nfc->chips);
> >   	init_completion(&nfc->completion);
> > -
> >   	nfc->dev = dev;
> >   
> > -	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > -	nfc->reg_base = devm_ioremap_resource(dev, res);
> > -	if (IS_ERR(nfc->reg_base))
> > -		return PTR_ERR(nfc->reg_base);
> > -
> > -	nfc->reg_clk =
> > -		syscon_regmap_lookup_by_phandle(dev->of_node,
> > -						"amlogic,mmc-syscon");
> > -	if (IS_ERR(nfc->reg_clk)) {
> > -		dev_err(dev, "Failed to lookup clock base\n");
> > -		return PTR_ERR(nfc->reg_clk);
> > +	ret = meson_nfc_reg_resource(dev, nfc);
> > +	if (ret) {
> > +		dev_err(dev, "Failed to get reg resource\n");
> > +		return ret;
> >   	}
> >   
> >   	irq = platform_get_irq(pdev, 0);
>
> .