From: Hou Zhiqiang <[email protected]>
To be compatible with legacy device, reset the addressing mode
to the default mode. Such as Freescale eSPI boot, it copies the
images from SPI flash without firing a reset signal previously,
so the reboot command will fail without reseting the addressing
mode of SPI flash.
Hou Zhiqiang (2):
mtd: spi-nor: add an API to restore the status of SPI flash chip
mtd: m25p80: restore the status of SPI flash when stop using it
Documentation/mtd/spi-nor.txt | 3 +++
drivers/mtd/devices/m25p80.c | 9 +++++++++
drivers/mtd/spi-nor/spi-nor.c | 10 ++++++++++
include/linux/mtd/spi-nor.h | 6 ++++++
4 files changed, 28 insertions(+)
--
2.14.1
From: Hou Zhiqiang <[email protected]>
Add this API to restore the status of SPI flash chip to the default
such as addressing mode, whenever detach the driver from device or
reboot the system.
Signed-off-by: Hou Zhiqiang <[email protected]>
---
V2:
- Changed the API name and added the comments and kernel document for it.
- Export this symbol for modules.
Documentation/mtd/spi-nor.txt | 3 +++
drivers/mtd/spi-nor/spi-nor.c | 10 ++++++++++
include/linux/mtd/spi-nor.h | 6 ++++++
3 files changed, 19 insertions(+)
diff --git a/Documentation/mtd/spi-nor.txt b/Documentation/mtd/spi-nor.txt
index 548d6306ebca..da1fbff5a24c 100644
--- a/Documentation/mtd/spi-nor.txt
+++ b/Documentation/mtd/spi-nor.txt
@@ -60,3 +60,6 @@ The main API is spi_nor_scan(). Before you call the hook, a driver should
initialize the necessary fields for spi_nor{}. Please see
drivers/mtd/spi-nor/spi-nor.c for detail. Please also refer to fsl-quadspi.c
when you want to write a new driver for a SPI NOR controller.
+Another API is spi_nor_restore(), this is used to restore the status of SPI
+flash chip such as addressing mode. Call it whenever detach the driver from
+device or reboot the system.
diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index bc266f70a15b..4a925378d434 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -2713,6 +2713,16 @@ static void spi_nor_resume(struct mtd_info *mtd)
dev_err(dev, "resume() failed\n");
}
+void spi_nor_restore(struct spi_nor *nor)
+{
+ /* restore the addressing mode */
+ if ((nor->addr_width == 4) &&
+ (JEDEC_MFR(nor->info) != SNOR_MFR_SPANSION) &&
+ !(nor->info->flags & SPI_NOR_4B_OPCODES))
+ set_4byte(nor, nor->info, 0);
+}
+EXPORT_SYMBOL_GPL(spi_nor_restore);
+
int spi_nor_scan(struct spi_nor *nor, const char *name,
const struct spi_nor_hwcaps *hwcaps)
{
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index d0c66a0975cf..0a182c3d0884 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -399,4 +399,10 @@ struct spi_nor_hwcaps {
int spi_nor_scan(struct spi_nor *nor, const char *name,
const struct spi_nor_hwcaps *hwcaps);
+/*
+ * spi_nor_restore_addr_mode() - restore the status of SPI NOR
+ * @nor: the spi_nor structure
+ */
+void spi_nor_restore(struct spi_nor *nor);
+
#endif
--
2.14.1
From: Hou Zhiqiang <[email protected]>
Implement .shutdown function to restore the status in reboot
process, and add the same operation to the .remove function.
Signed-off-by: Hou Zhiqiang <[email protected]>
---
V2:
- Changed code format slightly.
drivers/mtd/devices/m25p80.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index dbe6a1de2bb8..a4e18f6aaa33 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -307,10 +307,18 @@ static int m25p_remove(struct spi_device *spi)
{
struct m25p *flash = spi_get_drvdata(spi);
+ spi_nor_restore(&flash->spi_nor);
+
/* Clean up MTD stuff. */
return mtd_device_unregister(&flash->spi_nor.mtd);
}
+static void m25p_shutdown(struct spi_device *spi)
+{
+ struct m25p *flash = spi_get_drvdata(spi);
+
+ spi_nor_restore(&flash->spi_nor);
+}
/*
* Do NOT add to this array without reading the following:
*
@@ -386,6 +394,7 @@ static struct spi_driver m25p80_driver = {
.id_table = m25p_ids,
.probe = m25p_probe,
.remove = m25p_remove,
+ .shutdown = m25p_shutdown,
/* REVISIT: many of these chips have deep power-down modes, which
* should clearly be entered on suspend() to minimize power use.
--
2.14.1
Hi Hou,
Le 05/12/2017 à 06:33, Zhiqiang Hou a écrit :
> From: Hou Zhiqiang <[email protected]>
>
> To be compatible with legacy device, reset the addressing mode
> to the default mode. Such as Freescale eSPI boot, it copies the
> images from SPI flash without firing a reset signal previously,
> so the reboot command will fail without reseting the addressing
> mode of SPI flash.
>
You should put this in one of the commit messages so it explains which
issue is fixed by your patches.
Otherwise, your series looks good to me :)
Best regards,
Cyrille
> Hou Zhiqiang (2):
> mtd: spi-nor: add an API to restore the status of SPI flash chip
> mtd: m25p80: restore the status of SPI flash when stop using it
>
> Documentation/mtd/spi-nor.txt | 3 +++
> drivers/mtd/devices/m25p80.c | 9 +++++++++
> drivers/mtd/spi-nor/spi-nor.c | 10 ++++++++++
> include/linux/mtd/spi-nor.h | 6 ++++++
> 4 files changed, 28 insertions(+)
>
Hi Cyrille,
Thanks a lot for your comments!
> -----Original Message-----
> From: Cyrille Pitchen [mailto:[email protected]]
> Sent: 2017年12月6日 4:41
> To: Z.q. Hou <[email protected]>; [email protected];
> [email protected]; [email protected];
> [email protected]; [email protected];
> [email protected]; [email protected]
> Subject: Re: [PATCHv2 0/2] mtd: m25p80: restore the addressing mode when
> stop using the flash
>
> Hi Hou,
>
> Le 05/12/2017 à 06:33, Zhiqiang Hou a écrit :
> > From: Hou Zhiqiang <[email protected]>
> >
> > To be compatible with legacy device, reset the addressing mode to the
> > default mode. Such as Freescale eSPI boot, it copies the images from
> > SPI flash without firing a reset signal previously, so the reboot
> > command will fail without reseting the addressing mode of SPI flash.
> >
>
> You should put this in one of the commit messages so it explains which issue is
> fixed by your patches.
Agree with you, and will do it in next version.
>
> Otherwise, your series looks good to me :)
>
> Best regards,
>
> Cyrille
>
> > Hou Zhiqiang (2):
> > mtd: spi-nor: add an API to restore the status of SPI flash chip
> > mtd: m25p80: restore the status of SPI flash when stop using it
> >
> > Documentation/mtd/spi-nor.txt | 3 +++ drivers/mtd/devices/m25p80.c
> > | 9 +++++++++ drivers/mtd/spi-nor/spi-nor.c | 10 ++++++++++
> > include/linux/mtd/spi-nor.h | 6 ++++++
> > 4 files changed, 28 insertions(+)
> >
Thanks,
Zhiqiang