On 09/06/2018 03:46 AM, Masahiro Yamada wrote:
2018-09-05 17:31 GMT+09:00 Marek Vasut marek.vasut@gmail.com:
On 08/24/2018 03:10 PM, Marek Vasut wrote:
On 08/24/2018 03:05 PM, Masahiro Yamada wrote:
Hi Marek,
Hi,
2018-08-21 22:57 GMT+09:00 Marek Vasut marex@denx.de:
Add optional reset support into the Denali NAND driver. In case there is a valid reset entry in the DT, the reset gets deasserted before the NAND controller gets used.
Signed-off-by: Marek Vasut marex@denx.de Cc: Masahiro Yamada yamada.masahiro@socionext.com
drivers/mtd/nand/denali_dt.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/drivers/mtd/nand/denali_dt.c b/drivers/mtd/nand/denali_dt.c index 65a7797f0f..6fcd7d3843 100644 --- a/drivers/mtd/nand/denali_dt.c +++ b/drivers/mtd/nand/denali_dt.c @@ -9,6 +9,7 @@ #include <linux/io.h> #include <linux/ioport.h> #include <linux/printk.h> +#include <reset.h>
#include "denali.h"
@@ -64,6 +65,7 @@ static int denali_dt_probe(struct udevice *dev) const struct denali_dt_data *data; struct clk clk; struct resource res;
struct reset_ctl reset_ctl; int ret; data = (void *)dev_get_driver_data(dev);@@ -97,6 +99,13 @@ static int denali_dt_probe(struct udevice *dev)
denali->clk_x_rate = clk_get_rate(&clk);
ret = reset_get_by_index(dev, 0, &reset_ctl);if (!ret) {reset_assert(&reset_ctl);udelay(2);reset_deassert(&reset_ctl);}return denali_init(denali);}
I was testing this patch today because my SoC also has a reset line for NAND.
This patch looks trivial enough, but if the NAND is reset here, my board fails to boot with "nand_base: timeout while waiting for chip to become ready"
I do not know why. Please give me more time to figure out what is going on in my SoC.
Sure. Maybe you need to un-reset more stuff or the reset polarity is wrong ?
I do not think so.
The reset sequence of Denali is not so simple as you may think because the HW sequencer runs after the reset de-assertion. It includes some SoC-dependent parts.
Did you figure something out ?
Just testing one of my boards.
It booted by adding mdelay() after reset_deassert().
reset_assert(&reset_ctl); udelay(2); reset_deassert(&reset_ctl); mdelay(1); /* Why is this long delay required? */
It works right away after ungating the reset on my board.
I will read HW docs more, and talk to HW engineers to figure out the right solution.
OK