diff options
author | Masahiro Yamada <yamada.masahiro@socionext.com> | 2017-06-13 22:45:40 +0900 |
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committer | Boris Brezillon <boris.brezillon@free-electrons.com> | 2017-06-20 09:14:34 +0200 |
commit | f486287d2372422d68768c88fe54e80a48aee8ec (patch) | |
tree | a8fa9ad05bd02af3816c397d36098805e0cd3425 /drivers/mtd | |
parent | fa6134e5457d3177b82b35fa4004505f2571150a (diff) | |
download | linux-f486287d2372422d68768c88fe54e80a48aee8ec.tar.bz2 |
mtd: nand: denali: fix bank reset function to detect the number of chips
The nand_scan_ident() iterates over maxchips, and calls nand_reset()
for each. This driver currently passes the maximum number of banks
(=chip selects) supported by the controller as maxchips. So, maxchips
is typically 4 or 8. Usually, less number of NAND chips are connected
to the controller.
This can be a problem for ONFi devices. Now, this driver implements
->setup_data_interface() hook, so nand_setup_data_interface() issues
Set Features (0xEF) command, which waits until the chip returns R/B#
response. If no chip there, we know it never happens, but the driver
still ends up with waiting for a long time. It will finally bail-out
with timeout error and the driver will work with existing chips, but
unnecessary wait will give a bad user experience.
The denali_nand_reset() polls the INTR__RST_COMP and INTR__TIME_OUT
bits, but they are always set even if not NAND chip is connected to
that bank. To know the chip existence, INTR__INT_ACT bit must be
checked; this flag is set only when R/B# is toggled. Since the Reset
(0xFF) command toggles the R/B# pin, this can be used to know the
actual number of chips, and update denali->max_banks.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Diffstat (limited to 'drivers/mtd')
-rw-r--r-- | drivers/mtd/nand/denali.c | 52 |
1 files changed, 23 insertions, 29 deletions
diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c index 8091ba0916cc..3169ba58c58a 100644 --- a/drivers/mtd/nand/denali.c +++ b/drivers/mtd/nand/denali.c @@ -85,33 +85,6 @@ static void index_addr(struct denali_nand_info *denali, iowrite32(data, denali->flash_mem + 0x10); } -/* Reset the flash controller */ -static uint16_t denali_nand_reset(struct denali_nand_info *denali) -{ - int i; - - for (i = 0; i < denali->max_banks; i++) - iowrite32(INTR__RST_COMP | INTR__TIME_OUT, - denali->flash_reg + INTR_STATUS(i)); - - for (i = 0; i < denali->max_banks; i++) { - iowrite32(1 << i, denali->flash_reg + DEVICE_RESET); - while (!(ioread32(denali->flash_reg + INTR_STATUS(i)) & - (INTR__RST_COMP | INTR__TIME_OUT))) - cpu_relax(); - if (ioread32(denali->flash_reg + INTR_STATUS(i)) & - INTR__TIME_OUT) - dev_dbg(denali->dev, - "NAND Reset operation timed out on bank %d\n", i); - } - - for (i = 0; i < denali->max_banks; i++) - iowrite32(INTR__RST_COMP | INTR__TIME_OUT, - denali->flash_reg + INTR_STATUS(i)); - - return PASS; -} - /* * Use the configuration feature register to determine the maximum number of * banks that the hardware supports. @@ -1053,7 +1026,28 @@ static int denali_setup_data_interface(struct mtd_info *mtd, int chipnr, return 0; } -/* Initialization code to bring the device up to a known good state */ +static void denali_reset_banks(struct denali_nand_info *denali) +{ + int i; + + denali_clear_irq_all(denali); + + for (i = 0; i < denali->max_banks; i++) { + iowrite32(1 << i, denali->flash_reg + DEVICE_RESET); + while (!(ioread32(denali->flash_reg + INTR_STATUS(i)) & + (INTR__RST_COMP | INTR__TIME_OUT))) + cpu_relax(); + if (!(ioread32(denali->flash_reg + INTR_STATUS(i)) & + INTR__INT_ACT)) + break; + } + + dev_dbg(denali->dev, "%d chips connected\n", i); + denali->max_banks = i; + + denali_clear_irq_all(denali); +} + static void denali_hw_init(struct denali_nand_info *denali) { /* @@ -1073,7 +1067,7 @@ static void denali_hw_init(struct denali_nand_info *denali) denali->bbtskipbytes = ioread32(denali->flash_reg + SPARE_AREA_SKIP_BYTES); detect_max_banks(denali); - denali_nand_reset(denali); + denali_reset_banks(denali); iowrite32(0x0F, denali->flash_reg + RB_PIN_ENABLED); iowrite32(CHIP_EN_DONT_CARE__FLAG, denali->flash_reg + CHIP_ENABLE_DONT_CARE); |