Re: [U-Boot] [PATCH 4/9] drivers: nand: implement a NAND uclass

Hi Mugunthan,

On 20 April 2016 at 23:55, Mugunthan V N mugunthanvnm@ti.com wrote:

On Wednesday 20 April 2016 08:09 PM, Simon Glass wrote:

...

Hi Mugunthan,

On 1 April 2016 at 05:29, Mugunthan V N mugunthanvnm@ti.com wrote:

...

Implement a NAND uclass so that the NAND devices can be accessed via the DM framework.

Signed-off-by: Mugunthan V N mugunthanvnm@ti.com

drivers/mtd/nand/Kconfig | 10 +++++++ drivers/mtd/nand/Makefile | 2 ++ drivers/mtd/nand/nand-uclass.c | 62 ++++++++++++++++++++++++++++++++++++++++++ drivers/mtd/nand/nand.c | 6 +++- include/dm/uclass-id.h | 1 + include/nand.h | 5 ++++ 6 files changed, 85 insertions(+), 1 deletion(-) create mode 100644 drivers/mtd/nand/nand-uclass.c

diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig index 7787505..53b57b8 100644 --- a/drivers/mtd/nand/Kconfig +++ b/drivers/mtd/nand/Kconfig @@ -8,6 +8,16 @@ menuconfig NAND

if NAND

+config DM_NAND

•   bool "Enable driver model for NAND"
  

•   depends on NAND && DM
  

•   help
  

•     Enable driver model for NAND. The NAND interface is then
  

•     implemented by the NAND uclass. Multiple NAND devices can
  

•     be attached and used. The 'nand' command works as normal.
  

•     If the NAND drivers doesn't support DM, say N.
  

config SYS_NAND_SELF_INIT bool help diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile index 6fb3718..7745705 100644 --- a/drivers/mtd/nand/Makefile +++ b/drivers/mtd/nand/Makefile @@ -39,6 +39,8 @@ endif # not spl

ifdef NORMAL_DRIVERS

+obj-$(CONFIG_DM_NAND) += nand-uclass.o

obj-$(CONFIG_NAND_ECC_BCH) += nand_bch.o

obj-$(CONFIG_NAND_ATMEL) += atmel_nand.o diff --git a/drivers/mtd/nand/nand-uclass.c b/drivers/mtd/nand/nand-uclass.c new file mode 100644 index 0000000..d68d357 --- /dev/null +++ b/drivers/mtd/nand/nand-uclass.c @@ -0,0 +1,62 @@ +/*

• • NAND uclass driver for NAND bus.
• • (C) Copyright 2012-2016

• • Texas Instruments Incorporated, <www.ti.com>
    

• • SPDX-License-Identifier: GPL-2.0+
• */

+#include <common.h> +#include <dm.h> +#include <errno.h> +#include <nand.h>

+DECLARE_GLOBAL_DATA_PTR;

+#ifdef CONFIG_DM_NAND

+nand_info_t *get_nand_dev_by_index(int idx) +{

•   nand_info_t *nand;
  

•   struct udevice *dev;
  

•   int ret;
  

•   ret = uclass_get_device(UCLASS_NAND, idx, &dev);
  

•   if (ret) {
  

•           error("NAND device (%d) not found\n", idx);
  

This should return -ENODEV. Also please avoid printf() in drivers. The caller can report the error.

Return type is pointer so returned NULL and NULL denotes no dev. Will change this error to debug in v2.

OK, I see that this is the existing API.

...

...

•           return NULL;
  

•   }
  

•   nand = (nand_info_t *)dev_get_uclass_priv(dev);
  

•   if (!nand) {
  

•           error("Nand device not ready\n");
  

•           return NULL;
  

•   }
  

But if the device has been probed ((with uclass_get_device()) then this cannot be NULL.

This check is just a failsafe. ideally it should not fail here.

I cannot get to probe the device without this data, since this would be a bug in DM. So the check has no value.

[snip]

Regards, Simon