Re: [PATCH v2 4/9] mtd: rawnand: jz4780: Add support for the JZ4740

[Paul Cercueil <paul@xxxxxxxxxxxxxxx>]

Le dim. 3 févr. 2019 à 4:31, Boris Brezillon <bbrezillon@xxxxxxxxxx> 
a écrit :
> On Sat,  2 Feb 2019 20:19:21 -0300
> Paul Cercueil <paul@xxxxxxxxxxxxxxx> wrote:
>
> >  Add support for probing the jz4780-nand driver on the JZ4740 SoC 
> > from
> >  Ingenic.
> >
> >  Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
> >  ---
> >
> >  Changes:
> >
> >  v2: - Add support for the JZ4740 and not the JZ4725B: they behave 
> > the
> >        same, and JZ4740 is fully upstream while JZ4725B is not. The
> >        JZ4725B devicetree will then simply use the 
> > "ingenic,jz4740-nand"
> >        compatible string.
> >      - Fix the number of bytes for the ECC when the ECC strength is 
> > 4.
> >        This is needed for the JZ4740, which uses Reed-Solomon 
> > instead of
> >        BCH.
> >
> >   drivers/mtd/nand/raw/ingenic/jz4780_nand.c | 48 
> > +++++++++++++++++-----
>
> If we're going to make the driver compatible with jz4740 and jz4725b
> maybe we should rename the source files jz47xx_{nand,bch}.{c,h}.

I don't know about that. Adding support for new hardware isn't a good 
reason to
rename the driver, or so I've been told around here, as you then make 
it harder
to review the git history of the driver.

> >   1 file changed, 37 insertions(+), 11 deletions(-)
> >
> >  diff --git a/drivers/mtd/nand/raw/ingenic/jz4780_nand.c 
> > b/drivers/mtd/nand/raw/ingenic/jz4780_nand.c
> >  index 7f55358b860f..c0855fef7735 100644
> >  --- a/drivers/mtd/nand/raw/ingenic/jz4780_nand.c
> >  +++ b/drivers/mtd/nand/raw/ingenic/jz4780_nand.c
> >  @@ -13,6 +13,7 @@
> >   #include <linux/module.h>
> >   #include <linux/of.h>
> >   #include <linux/of_address.h>
> >  +#include <linux/of_device.h>
> >   #include <linux/gpio/consumer.h>
> >   #include <linux/platform_device.h>
> >   #include <linux/slab.h>
> >  @@ -26,13 +27,15 @@
> >
> >   #define DRV_NAME	"jz4780-nand"
> >
> >  -#define OFFSET_DATA	0x00000000
> >  -#define OFFSET_CMD	0x00400000
> >  -#define OFFSET_ADDR	0x00800000
> >  -
> >   /* Command delay when there is no R/B pin. */
> >   #define RB_DELAY_US	100
> >
> >  +struct jz_soc_info {
> >  +	unsigned long data_offset;
> >  +	unsigned long addr_offset;
> >  +	unsigned long cmd_offset;
> >  +};
> >  +
> >   struct jz4780_nand_cs {
> >   	unsigned int bank;
> >   	void __iomem *base;
> >  @@ -40,6 +43,7 @@ struct jz4780_nand_cs {
> >
> >   struct jz4780_nand_controller {
> >   	struct device *dev;
> >  +	const struct jz_soc_info *soc_info;
> >   	struct jz4780_bch *bch;
> >   	struct nand_controller controller;
> >   	unsigned int num_banks;
> >  @@ -101,9 +105,9 @@ static void jz4780_nand_cmd_ctrl(struct 
> > nand_chip *chip, int cmd,
> >   		return;
> >
> >   	if (ctrl & NAND_ALE)
> >  -		writeb(cmd, cs->base + OFFSET_ADDR);
> >  +		writeb(cmd, cs->base + nfc->soc_info->addr_offset);
> >   	else if (ctrl & NAND_CLE)
> >  -		writeb(cmd, cs->base + OFFSET_CMD);
> >  +		writeb(cmd, cs->base + nfc->soc_info->cmd_offset);
> >   }
> >
> >   static int jz4780_nand_dev_ready(struct nand_chip *chip)
> >  @@ -161,8 +165,13 @@ static int jz4780_nand_attach_chip(struct 
> > nand_chip *chip)
> >   	struct jz4780_nand_controller *nfc = 
> > to_jz4780_nand_controller(chip->controller);
> >   	int eccbytes;
> >
> >  -	chip->ecc.bytes = fls((1 + 8) * chip->ecc.size)	*
> >  -				(chip->ecc.strength / 8);
> >  +	if (chip->ecc.strength == 4) {
> >  +		/* JZ4740 uses 9 bytes of ECC to correct maximum 4 errors */
> >  +		chip->ecc.bytes = 9;
> >  +	} else {
> >  +		chip->ecc.bytes = fls((1 + 8) * chip->ecc.size)	*
> >  +				  (chip->ecc.strength / 8);
> >  +	}
> >
> >   	switch (chip->ecc.mode) {
> >   	case NAND_ECC_HW:
> >  @@ -272,8 +281,8 @@ static int jz4780_nand_init_chip(struct 
> > platform_device *pdev,
> >   		return -ENOMEM;
> >   	mtd->dev.parent = dev;
> >
> >  -	chip->legacy.IO_ADDR_R = cs->base + OFFSET_DATA;
> >  -	chip->legacy.IO_ADDR_W = cs->base + OFFSET_DATA;
> >  +	chip->legacy.IO_ADDR_R = cs->base + nfc->soc_info->data_offset;
> >  +	chip->legacy.IO_ADDR_W = cs->base + nfc->soc_info->data_offset;
> >   	chip->legacy.chip_delay = RB_DELAY_US;
> >   	chip->options = NAND_NO_SUBPAGE_WRITE;
> >   	chip->legacy.select_chip = jz4780_nand_select_chip;
> >  @@ -353,6 +362,10 @@ static int jz4780_nand_probe(struct 
> > platform_device *pdev)
> >   	if (!nfc)
> >   		return -ENOMEM;
> >
> >  +	nfc->soc_info = device_get_match_data(dev);
> >  +	if (!nfc->soc_info)
> >  +		return -EINVAL;
> >  +
> >   	/*
> >   	 * Check for BCH HW before we call nand_scan_ident, to prevent us 
> > from
> >   	 * having to call it again if the BCH driver returns 
> > -EPROBE_DEFER.
> >  @@ -390,8 +403,21 @@ static int jz4780_nand_remove(struct 
> > platform_device *pdev)
> >   	return 0;
> >   }
> >
> >  +static const struct jz_soc_info jz4740_soc_info = {
> >  +	.data_offset = 0x00000000,
> >  +	.cmd_offset  = 0x00008000,
> >  +	.addr_offset = 0x00010000,
> >  +};
> >  +
> >  +static const struct jz_soc_info jz4780_soc_info = {
> >  +	.data_offset = 0x00000000,
> >  +	.cmd_offset  = 0x00400000,
> >  +	.addr_offset = 0x00800000,
> >  +};
> >  +
> >   static const struct of_device_id jz4780_nand_dt_match[] = {
> >  -	{ .compatible = "ingenic,jz4780-nand" },
> >  +	{ .compatible = "ingenic,jz4740-nand", .data = &jz4740_soc_info },
> >  +	{ .compatible = "ingenic,jz4780-nand",  .data = &jz4780_soc_info  
> > },
> >   	{},
> >   };
> >   MODULE_DEVICE_TABLE(of, jz4780_nand_dt_match);