From: Boris Brezillon <boris.brezillon@bootlin.com>
To: Bean Huo <beanhuo@outlook.com>
Cc: "boris.brezillon@free-elections.com"
<boris.brezillon@free-elections.com>,
"mark.rutland@arm.com" <mark.rutland@arm.com>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"richard@nod.at" <richard@nod.at>,
"marek.vasut@gmail.com" <marek.vasut@gmail.com>,
"robh+dt@kernel.org" <robh+dt@kernel.org>,
"linux-mtd@lists.infradead.org" <linux-mtd@lists.infradead.org>,
"cyrille.pitchen@wedev4u.fr" <cyrille.pitchen@wedev4u.fr>,
"computersforpeace@gmail.com" <computersforpeace@gmail.com>,
"dwmw2@infradead.org" <dwmw2@infradead.org>,
beanhuo <beanhuo@micron.com>
Subject: Re: [PATCH v1 3/3] drivers: mtd: chips: add support for the dual die stacked PNOR
Date: Thu, 22 Feb 2018 14:33:57 +0100 [thread overview]
Message-ID: <20180222143357.4ec680b6@bbrezillon> (raw)
In-Reply-To: <DM2PR12MB00143807EEF9602098FF0D4BA6CE0@DM2PR12MB0014.namprd12.prod.outlook.com>
On Wed, 21 Feb 2018 19:32:37 +0000
Bean Huo <beanhuo@outlook.com> wrote:
> From: beanhuo <beanhuo@micron.com>
>
> For the dual die stacked parallel NOR flash (PNOR), it comprises
> two dies in the stack. These two dies can receive the commands in
> parallel, but there is only one die can be selected or accept
> commands according to the maximum address line A[max].
> For example,Micron parallel NOR MT28FW02GBBA1HPC and Cypress
> S70GL02GS, both are dual-die stacked PNOR with 2Gbit density,
> and maximum address line A[26], when A[26] == 0, the lower 1Gb die
> is selected, when A[26] == 1, the upper 1Gb is selected.
>
> This patch is to check the accessing offset in the chip and rebase
> the unlock cycle command base addresses.
>
> Signed-off-by: beanhuo <beanhuo@micron.com>
> ---
> drivers/mtd/chips/cfi_cmdset_0002.c | 144 ++++++++++++++++++++++++++++--------
> 1 file changed, 113 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c
> index 56aa6b7..8fa2193 100644
> --- a/drivers/mtd/chips/cfi_cmdset_0002.c
> +++ b/drivers/mtd/chips/cfi_cmdset_0002.c
> @@ -1104,6 +1104,27 @@ do { \
>
> #endif
>
> +/*
> + * The dual die stacked device comprises two identical dies which connected
^are
> + * in parallel.But there is only one die being selected each time according
^ missing space after the period
> + * to maximum address line A[max]. When A[max] == 0, the lower die is selected,
> + * when A[max] == 1, the upper die is selected. This function will reture the
^return
> + * CFI unlock-command base address accrording to accessing address.
Is it really just about unlock commands?
> + */
> +static loff_t get_cmd_base_address(struct map_info *map, struct flchip *chip,
> + loff_t offset)
> +{
> + struct cfi_private *cfi = map->fldrv_priv;
> + unsigned long cmd_base_addr = chip->start;
> +
> + if (cfi->device_stack == CFI_DEVICESTACK_2DIE) {
> + if (offset >= (1 << (cfi->cfiq->DevSize - 1)))
> + cmd_base_addr += (1 << (cfi->cfiq->DevSize - 1));
> + }
Could be done in a more generic way:
unsigned long die = offset >> (cfi->cfiq->DevSize - 1);
if (cfi->device_stack == 1) {
WARN_ON(die);
return cmd_base_addr;
}
cmd_base_addr += die << (cfi->cfiq->DevSize - 1);
> +
> + return cmd_base_addr;
> +}
> +
> static inline int do_read_onechip(struct map_info *map, struct flchip *chip, loff_t adr, size_t len, u_char *buf)
> {
> unsigned long cmd_addr;
> @@ -1180,12 +1201,18 @@ static inline void otp_enter(struct map_info *map, struct flchip *chip,
> loff_t adr, size_t len)
> {
> struct cfi_private *cfi = map->fldrv_priv;
> + unsigned long cmd_base_addr;
>
> - cfi_send_gen_cmd(0xAA, cfi->addr_unlock1, chip->start, map, cfi,
> + /* For the dual die device, rebase the command base address according
Please do not use net-style comments.
--
Boris Brezillon, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com
______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/
prev parent reply other threads:[~2018-02-22 13:33 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1519241514-6466-1-git-send-email-beanhuo@outlook.com>
2018-02-21 19:32 ` [PATCH v1 1/3] mtd: physmap: add dual die entry in devicetree binding Bean Huo
2018-02-22 13:05 ` Boris Brezillon
2018-02-23 11:07 ` Bean Huo
2018-02-23 15:53 ` Boris Brezillon
2018-02-21 19:32 ` [PATCH v1 2/3] mtd: probe: probe dual die entry from " Bean Huo
2018-02-22 13:02 ` Boris Brezillon
2018-02-23 11:14 ` Bean Huo
2018-02-21 19:32 ` [PATCH v1 3/3] drivers: mtd: chips: add support for the dual die stacked PNOR Bean Huo
2018-02-22 13:33 ` Boris Brezillon [this message]
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