[U-Boot] [PATCH 1/2] nand: Introduce CONFIG_SYS_NAND_SELF_INIT
Scott Wood
scottwood at freescale.com
Fri Jan 13 02:59:16 CET 2012
This allows a driver to run code between nand_scan_ident() and
nand_scan_tail(), among other things. See the additions to
doc/README.nand for details.
To allow a gradual transition, Boards that don't set
CONFIG_SYS_NAND_SELF_INIT will still be initialized the old way, but
new drivers should not require this, and existing drivers should be
converted when convenient.
Signed-off-by: Scott Wood <scottwood at freescale.com>
---
doc/README.nand | 62 ++++++++++++++++++++++++++++++
drivers/mtd/nand/nand.c | 96 +++++++++++++++++++++++++++++------------------
include/nand.h | 5 ++
3 files changed, 126 insertions(+), 37 deletions(-)
diff --git a/doc/README.nand b/doc/README.nand
index 023740e..04a87c9 100644
--- a/doc/README.nand
+++ b/doc/README.nand
@@ -120,6 +120,68 @@ Configuration Options:
CONFIG_SYS_NAND_MAX_CHIPS
The maximum number of NAND chips per device to be supported.
+ CONFIG_SYS_NAND_SELF_INIT
+ Traditionally, glue code in drivers/mtd/nand/nand.c has driven
+ the initialization process -- it provides the mtd and nand
+ structs, calls a board init function for a specific device,
+ calls nand_scan(), and registers with mtd.
+
+ This arrangement does not provide drivers with the flexibility to
+ run code between nand_scan_ident() and nand_scan_tail(), or other
+ deviations from the "normal" flow.
+
+ If a board defines CONFIG_SYS_NAND_SELF_INIT, drivers/mtd/nand/nand.c
+ will make one call to board_nand_init(), with no arguments. That
+ function is responsible for calling a driver init function for
+ each NAND device on the board, that performs all initialization
+ tasks except setting mtd->name, and registering with the rest of
+ U-Boot. Those last tasks are accomplished by calling nand_register()
+ on the new mtd device.
+
+ Example of new init to be added to the end of an existing driver
+ init:
+
+ /*
+ * devnum is the device number to be used in nand commands
+ * and in mtd->name. Must be less than
+ * CONFIG_SYS_NAND_MAX_DEVICE.
+ */
+ mtd = &nand_info[devnum];
+
+ /* chip is struct nand_chip, and is now provided by the driver. */
+ mtd->priv = &chip;
+
+ /*
+ * Fill in appropriate values if this driver uses these fields,
+ * or uses the standard read_byte/write_buf/etc. functions from
+ * nand_base.c that use these fields.
+ */
+ chip.IO_ADDR_R = ...;
+ chip.IO_ADDR_W = ...;
+
+ if (nand_scan_ident(mtd, CONFIG_SYS_MAX_NAND_CHIPS, NULL))
+ error out
+
+ /*
+ * Insert here any code you wish to run after the chip has been
+ * identified, but before any other I/O is done.
+ */
+
+ if (nand_scan_tail(mtd))
+ error out
+
+ if (nand_register(devnum))
+ error out
+
+ In addition to providing more flexibility to the driver, it reduces
+ the difference between a U-Boot driver and its Linux counterpart.
+ nand_init() is now reduced to calling board_nand_init() once, and
+ printing a size summary. This should also make it easier to
+ transition to delayed NAND initialization.
+
+ Please convert your driver even if you don't need the extra
+ flexibility, so that one day we can eliminate the old mechanism.
+
NOTE:
=====
diff --git a/drivers/mtd/nand/nand.c b/drivers/mtd/nand/nand.c
index d987f4c..4cf4c1c 100644
--- a/drivers/mtd/nand/nand.c
+++ b/drivers/mtd/nand/nand.c
@@ -23,6 +23,7 @@
#include <common.h>
#include <nand.h>
+#include <errno.h>
#ifndef CONFIG_SYS_NAND_BASE_LIST
#define CONFIG_SYS_NAND_BASE_LIST { CONFIG_SYS_NAND_BASE }
@@ -31,63 +32,84 @@
DECLARE_GLOBAL_DATA_PTR;
int nand_curr_device = -1;
+
+
nand_info_t nand_info[CONFIG_SYS_MAX_NAND_DEVICE];
+#ifndef CONFIG_SYS_NAND_SELF_INIT
static struct nand_chip nand_chip[CONFIG_SYS_MAX_NAND_DEVICE];
static ulong base_address[CONFIG_SYS_MAX_NAND_DEVICE] = CONFIG_SYS_NAND_BASE_LIST;
+#endif
+
+static char dev_name[CONFIG_SYS_MAX_NAND_DEVICE][8];
+
+static unsigned long total_nand_size; /* in kiB */
+
+/* Register an initialized NAND mtd device with the U-Boot NAND command. */
+int nand_register(int devnum)
+{
+ struct mtd_info *mtd;
+
+ if (devnum >= CONFIG_SYS_MAX_NAND_DEVICE)
+ return -EINVAL;
+
+ mtd = &nand_info[devnum];
+
+ sprintf(dev_name[devnum], "nand%d", devnum);
+ mtd->name = dev_name[devnum];
+
+#ifdef CONFIG_MTD_DEVICE
+ /*
+ * Add MTD device so that we can reference it later
+ * via the mtdcore infrastructure (e.g. ubi).
+ */
+ add_mtd_device(mtd);
+#endif
+
+ total_nand_size += mtd->size / 1024;
-static const char default_nand_name[] = "nand";
-static __attribute__((unused)) char dev_name[CONFIG_SYS_MAX_NAND_DEVICE][8];
+ if (nand_curr_device == -1)
+ nand_curr_device = devnum;
+
+ return 0;
+}
-static void nand_init_chip(struct mtd_info *mtd, struct nand_chip *nand,
- ulong base_addr)
+#ifndef CONFIG_SYS_NAND_SELF_INIT
+static void nand_init_chip(int i)
{
+ struct mtd_info *mtd = &nand_info[i];
+ struct nand_chip *nand = &nand_chip[i];
+ ulong base_addr = base_address[i];
int maxchips = CONFIG_SYS_NAND_MAX_CHIPS;
- static int __attribute__((unused)) i = 0;
if (maxchips < 1)
maxchips = 1;
- mtd->priv = nand;
+ mtd->priv = nand;
nand->IO_ADDR_R = nand->IO_ADDR_W = (void __iomem *)base_addr;
- if (board_nand_init(nand) == 0) {
- if (nand_scan(mtd, maxchips) == 0) {
- if (!mtd->name)
- mtd->name = (char *)default_nand_name;
-#ifdef CONFIG_NEEDS_MANUAL_RELOC
- else
- mtd->name += gd->reloc_off;
-#endif
-#ifdef CONFIG_MTD_DEVICE
- /*
- * Add MTD device so that we can reference it later
- * via the mtdcore infrastructure (e.g. ubi).
- */
- sprintf(dev_name[i], "nand%d", i);
- mtd->name = dev_name[i++];
- add_mtd_device(mtd);
-#endif
- } else
- mtd->name = NULL;
- } else {
- mtd->name = NULL;
- mtd->size = 0;
- }
+ if (board_nand_init(nand))
+ return;
+ if (nand_scan(mtd, maxchips))
+ return;
+
+ nand_register(i);
}
+#endif
void nand_init(void)
{
+#ifdef CONFIG_SYS_NAND_SELF_INIT
+ board_nand_init();
+#else
int i;
- unsigned int size = 0;
- for (i = 0; i < CONFIG_SYS_MAX_NAND_DEVICE; i++) {
- nand_init_chip(&nand_info[i], &nand_chip[i], base_address[i]);
- size += nand_info[i].size / 1024;
- if (nand_curr_device == -1)
- nand_curr_device = i;
- }
- printf("%u MiB\n", size / 1024);
+
+ for (i = 0; i < CONFIG_SYS_MAX_NAND_DEVICE; i++)
+ nand_init_chip(i);
+#endif
+
+ printf("%lu MiB\n", total_nand_size / 1024);
#ifdef CONFIG_SYS_NAND_SELECT_DEVICE
/*
diff --git a/include/nand.h b/include/nand.h
index d444ddc..5dd1710 100644
--- a/include/nand.h
+++ b/include/nand.h
@@ -30,7 +30,12 @@ extern void nand_init(void);
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
+#ifdef CONFIG_SYS_NAND_SELF_INIT
+void board_nand_init(void);
+int nand_register(int devnum);
+#else
extern int board_nand_init(struct nand_chip *nand);
+#endif
typedef struct mtd_info nand_info_t;
--
1.7.7.rc3.4.g8d714
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