To simplify porting kernel NAND drivers a tiny bit, provide the Linux
nand_gpio_waitrdy. This is readily implementable with barebox' own
gpio_poll_timeout_us.
Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
---
drivers/mtd/nand/nand_base.c | 22 ++++++++++++++++++++++
include/linux/mtd/rawnand.h | 2 ++
2 files changed, 24 insertions(+)
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 4c90ad975771..c3cd22935bb2 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -36,6 +36,7 @@
#include <asm/byteorder.h>
#include <io.h>
#include <malloc.h>
+#include <gpio.h>
#include <module.h>
#include <of_mtd.h>
@@ -785,6 +786,27 @@ int nand_soft_waitrdy(struct nand_chip *chip, unsigned long timeout_ms)
};
EXPORT_SYMBOL_GPL(nand_soft_waitrdy);
+/**
+ * nand_gpio_waitrdy - Poll R/B GPIO pin until ready
+ * @chip: NAND chip structure
+ * @gpiod: GPIO descriptor of R/B pin
+ * @timeout_ms: Timeout in ms
+ *
+ * Poll the R/B GPIO pin until it becomes ready. If that does not happen
+ * whitin the specified timeout, -ETIMEDOUT is returned.
+ *
+ * This helper is intended to be used when the controller has access to the
+ * NAND R/B pin over GPIO.
+ *
+ * Return 0 if the R/B pin indicates chip is ready, a negative error otherwise.
+ */
+int nand_gpio_waitrdy(struct nand_chip *chip, int gpio,
+ unsigned long timeout_ms)
+{
+ return gpio_poll_timeout_us(gpio, true, timeout_ms * USEC_PER_MSEC);
+};
+EXPORT_SYMBOL_GPL(nand_gpio_waitrdy);
+
static bool nand_supports_get_features(struct nand_chip *chip, int addr)
{
return (chip->parameters.supports_set_get_features &&
diff --git a/include/linux/mtd/rawnand.h b/include/linux/mtd/rawnand.h
index 1147f235a680..a05c67e1404b 100644
--- a/include/linux/mtd/rawnand.h
+++ b/include/linux/mtd/rawnand.h
@@ -1414,6 +1414,8 @@ void nand_cleanup(struct nand_chip *chip);
* instruction and have no physical pin to check it.
*/
int nand_soft_waitrdy(struct nand_chip *chip, unsigned long timeout_ms);
+int nand_gpio_waitrdy(struct nand_chip *chip, int gpio,
+ unsigned long timeout_ms);
/* Select/deselect a NAND target. */
void nand_select_target(struct nand_chip *chip, unsigned int cs);
--
2.30.2
