Re: [OpenWrt-Devel] 回复：[PATCH] ramips: reset m25p80 when shutdown

[Daniel Golle]

On Sat, Nov 21, 2015 at 09:41:25PM +0100, John Crispin wrote:
> Hi,
> 
> one more request
> 
> On 16/11/2015 18:03, 未命名 wrote:
> > Instead of use the set_4byte function in spi-nor.c, I use this patch
> > for simplest modification. In fact, set_4byte also send 0xe9 command to
> > the spi flash.

Using set_4byte also already contains the logic to check which vendor-
specific 4-byte mode to use (EN4B/EX4B or via explicite read4/write4
commands). Surely, having spi-nor provide a generic shutdown functions
using set_4byte and then using that in m25p80 is less simple than
implementing the work-around only in m25p80...


> > 
> > Signed-off-by: Shonn Lu 
> > ---
> >  .../0064-reset-m25p80-when-shutdown.patch  | 27
> > ++
> >  1 file changed, 27 insertions(+)
> >  create mode 100644
> > target/linux/ramips/patches-3.18/0064-reset-m25p80-when-shutdown.patch
> > 
> > diff --git
> > a/target/linux/ramips/patches-3.18/0064-reset-m25p80-when-shutdown.patch
> > b/target/linux/ramips/patches-3.18/0064-reset-m25p80-when-shutdown.patch
> > new file mode 100644
> > index 000..aca758d
> > --- /dev/null
> > +++ b/target/linux/ramips/patches-3.18/0064-reset-m25p80-when-shutdown.patch
> > @@ -0,0 +1,27 @@
> > +--- a/drivers/mtd/devices/m25p80.c
> >  b/drivers/mtd/devices/m25p80.c
> > +@@ -322,6 +322,16 @@
> > + {
> > + struct m25p *flash = spi_get_drvdata(spi);
> > +
> > ++ if ((>spi_nor)->addr_width > 3) {
> > ++ printk(KERN_INFO "m25p80: exit 4-byte address mode\n");
> > ++ flash->command[0] = SPINOR_OP_EX4B;  // exit 4-byte address mode: 0xe9
> > ++ spi_write(flash->spi, flash->command, 1);
> > ++ flash->command[0] = 0x66;  // enable reset
> > ++ spi_write(flash->spi, flash->command, 1); 
> > ++ flash->command[0] = 0x99;  // reset
> > ++ spi_write(flash->spi, flash->command, 1);

Are you sure the reset is actually needed?
When I tested on some Rt5350 boards, SPINOR_OP_EX4B (0xE9) did the job
and no subsequent reset was needed.

> 
> this needs to be indented with tabs
> 
>   John
> 


Cheers


Daniel
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Re: [OpenWrt-Devel] 回复：[PATCH] ramips: reset m25p80 when shutdown

[John Crispin]

Hi,

one more request

On 16/11/2015 18:03, 未命名 wrote:
> Instead of use the set_4byte function in spi-nor.c, I use this patch
> for simplest modification. In fact, set_4byte also send 0xe9 command to
> the spi flash.
> 
> Signed-off-by: Shonn Lu 
> ---
>  .../0064-reset-m25p80-when-shutdown.patch  | 27
> ++
>  1 file changed, 27 insertions(+)
>  create mode 100644
> target/linux/ramips/patches-3.18/0064-reset-m25p80-when-shutdown.patch
> 
> diff --git
> a/target/linux/ramips/patches-3.18/0064-reset-m25p80-when-shutdown.patch
> b/target/linux/ramips/patches-3.18/0064-reset-m25p80-when-shutdown.patch
> new file mode 100644
> index 000..aca758d
> --- /dev/null
> +++ b/target/linux/ramips/patches-3.18/0064-reset-m25p80-when-shutdown.patch
> @@ -0,0 +1,27 @@
> +--- a/drivers/mtd/devices/m25p80.c
>  b/drivers/mtd/devices/m25p80.c
> +@@ -322,6 +322,16 @@
> + {
> + struct m25p *flash = spi_get_drvdata(spi);
> +
> ++ if ((>spi_nor)->addr_width > 3) {
> ++ printk(KERN_INFO "m25p80: exit 4-byte address mode\n");
> ++ flash->command[0] = SPINOR_OP_EX4B;  // exit 4-byte address mode: 0xe9
> ++ spi_write(flash->spi, flash->command, 1);
> ++ flash->command[0] = 0x66;  // enable reset
> ++ spi_write(flash->spi, flash->command, 1); 
> ++ flash->command[0] = 0x99;  // reset
> ++ spi_write(flash->spi, flash->command, 1);

this needs to be indented with tabs

John

> ++ }
> ++
> + /* Clean up MTD stuff. */
> + return mtd_device_unregister(>mtd);
> + }
> +@@ -385,6 +395,7 @@
> + .id_table = m25p_ids,
> + .probe = m25p_probe,
> + .remove = m25p_remove,
> ++ .shutdown = m25p_remove, // add shutdown method to reset spi flash
> +
> + /* REVISIT: many of these chips have deep power-down modes, which
> + * should clearly be entered on suspend() to minimize power use.
> -- 
> 1.9.1
> 
> 
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> 
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[OpenWrt-Devel] 回复：[PATCH] ramips: reset m25p80 when shutdown

[未命名]

Instead of use the set_4byte function in spi-nor.c, I use this patch for 
simplest modification. In fact, set_4byte also send 0xe9 command to the spi 
flash.


Signed-off-by: Shonn Lu 
---
 .../0064-reset-m25p80-when-shutdown.patch  | 27 ++
 1 file changed, 27 insertions(+)
 create mode 100644 
target/linux/ramips/patches-3.18/0064-reset-m25p80-when-shutdown.patch

diff --git 
a/target/linux/ramips/patches-3.18/0064-reset-m25p80-when-shutdown.patch 
b/target/linux/ramips/patches-3.18/0064-reset-m25p80-when-shutdown.patch
new file mode 100644
index 000..aca758d
--- /dev/null
+++ b/target/linux/ramips/patches-3.18/0064-reset-m25p80-when-shutdown.patch
@@ -0,0 +1,27 @@
+--- a/drivers/mtd/devices/m25p80.c
 b/drivers/mtd/devices/m25p80.c
+@@ -322,6 +322,16 @@
+ {
+   struct m25p *flash = spi_get_drvdata(spi);
+ 
++  if ((>spi_nor)->addr_width > 3) {
++  printk(KERN_INFO "m25p80: exit 4-byte address mode\n");
++  flash->command[0] = SPINOR_OP_EX4B;  // exit 4-byte address mode: 0xe9
++  spi_write(flash->spi, flash->command, 1);
++  flash->command[0] = 0x66;  // enable reset
++  spi_write(flash->spi, flash->command, 1);  
++  flash->command[0] = 0x99;  // reset
++  spi_write(flash->spi, flash->command, 1);
++  }
++
+   /* Clean up MTD stuff. */
+   return mtd_device_unregister(>mtd);
+ }
+@@ -385,6 +395,7 @@
+   .id_table   = m25p_ids,
+   .probe  = m25p_probe,
+   .remove = m25p_remove,
++  .shutdown = m25p_remove, // add shutdown method to reset spi flash
+ 
+   /* REVISIT: many of these chips have deep power-down modes, which
+* should clearly be entered on suspend() to minimize power use.
-- 
1.9.1___
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[OpenWrt-Devel] 回复： [PATCH] ramips: reset m25p80 when shutdown

[未命名]

I do not test this patch on all the 32MB spi flash except my Youku YK1 router.I 
am looking forward to a generic shutdown function which adapt to Macronix or 
Winbond.

Cheers
Shonn___
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[OpenWrt-Devel] 回复： [PATCH] ramips: reset m25p80 when shutdown

[未命名]

http://www.winbond.com.tw/resource-files/w25q256fv_revh_02112015.pdf
The datasheet above shows that w25q256fv also use E9h to exit 4-Byte mode.___
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