[MTD] [NAND] driver extension to support NAND on TQM85xx modules
This patch extends the FSL UPM NAND driver from Anton Vorontsov to
support hardware which does not have the R/B pin of the NAND chip
connected, like the TQM8548 module:
- The OF_GPIO dependency has been removed from the Kconfig option
because GPIO is not needed. The relevant gpio_* function are then
stubbed out in <linux/gpio.h>.
- It re-introduces the chip-delay property to define an appropriate
maximum delay time (tR) required for read operations. The binding
will be documented in a separate patch.
Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/mtd/nand/fsl_upm.c b/drivers/mtd/nand/fsl_upm.c
index 3af5ef3..024e3ff 100644
--- a/drivers/mtd/nand/fsl_upm.c
+++ b/drivers/mtd/nand/fsl_upm.c
@@ -13,6 +13,7 @@
#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/delay.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/nand_ecc.h>
#include <linux/mtd/partitions.h>
@@ -36,6 +37,7 @@
uint8_t upm_cmd_offset;
void __iomem *io_base;
int rnb_gpio;
+ int chip_delay;
};
#define to_fsl_upm_nand(mtd) container_of(mtd, struct fsl_upm_nand, mtd)
@@ -58,10 +60,11 @@
if (fun->rnb_gpio >= 0) {
while (--cnt && !fun_chip_ready(&fun->mtd))
cpu_relax();
+ if (!cnt)
+ dev_err(fun->dev, "tired waiting for RNB\n");
+ } else {
+ ndelay(100);
}
-
- if (!cnt)
- dev_err(fun->dev, "tired waiting for RNB\n");
}
static void fun_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
@@ -129,7 +132,7 @@
fun->chip.IO_ADDR_R = fun->io_base;
fun->chip.IO_ADDR_W = fun->io_base;
fun->chip.cmd_ctrl = fun_cmd_ctrl;
- fun->chip.chip_delay = 50;
+ fun->chip.chip_delay = fun->chip_delay;
fun->chip.read_byte = fun_read_byte;
fun->chip.read_buf = fun_read_buf;
fun->chip.write_buf = fun_write_buf;
@@ -228,6 +231,12 @@
goto err2;
}
+ prop = of_get_property(ofdev->node, "chip-delay", NULL);
+ if (prop)
+ fun->chip_delay = *prop;
+ else
+ fun->chip_delay = 50;
+
fun->io_base = devm_ioremap_nocache(&ofdev->dev, io_res.start,
io_res.end - io_res.start + 1);
if (!fun->io_base) {