[PATCH v4 2/2] mtd: rawnand: macronix: Add support for deep power down mode

Mason Yang
2020-03-18T07:42:49Z

Macronix AD series support deep power down mode for a minimum
power consumption state.

Overload nand_suspend() & nand_resume() in Macronix specific code to
support deep power down mode.

Signed-off-by: Mason Yang <masonccyang@mxic.com.tw>
---
drivers/mtd/nand/raw/nand_macronix.c | 74 ++++++++++++++++++++++++++++++++++++
1 file changed, 74 insertions(+)

diff --git a/drivers/mtd/nand/raw/nand_macronix.c b/drivers/mtd/nand/raw/nand_macronix.c
index 3ff7ce0..756c175 100644
--- a/drivers/mtd/nand/raw/nand_macronix.c
+++ b/drivers/mtd/nand/raw/nand_macronix.c
@@ -6,11 +6,14 @@
* Author: Boris Brezillon <boris.brezillon@free-electrons.com>
*/

+#include "linux/delay.h"
#include "internals.h"

#define MACRONIX_READ_RETRY_BIT BIT(0)
#define MACRONIX_NUM_READ_RETRY_MODES 6

+#define MXIC_CMD_POWER_DOWN 0xB9
+
struct nand_onfi_vendor_macronix {
u8 reserved;
u8 reliability_func;
@@ -91,6 +94,76 @@ static void macronix_nand_fix_broken_get_timings(struct nand_chip *chip)
ONFI_FEATURE_ADDR_TIMING_MODE, 1);
}

+static int nand_power_down_op(struct nand_chip *chip)
+{
+ int ret;
+
+ if (nand_has_exec_op(chip)) {
+ struct nand_op_instr instrs[] = {
+ NAND_OP_CMD(MXIC_CMD_POWER_DOWN, 0),
+ };
+
+ struct nand_operation op = NAND_OPERATION(chip->cur_cs, instrs);
+
+ ret = nand_exec_op(chip, &op);
+ if (ret)
+ return ret;
+
+ } else {
+ chip->legacy.cmdfunc(chip, MXIC_CMD_POWER_DOWN, -1, -1);
+ }
+
+ return 0;
+}
+
+static int mxic_nand_suspend(struct nand_chip *chip)
+{
+ int ret;
+
+ nand_select_target(chip, 0);
+ ret = nand_power_down_op(chip);
+ if (ret < 0)
+ pr_err("Suspending MXIC NAND chip failed (%d)\n", ret);
+ nand_deselect_target(chip);
+
+ return ret;
+}
+
+static void mxic_nand_resume(struct nand_chip *chip)
+{
+ /*
+ * Toggle #CS pin to resume NAND device and don't care
+ * of the others CLE, #WE, #RE pins status.
+ * A NAND controller ensure it is able to assert/de-assert #CS
+ * by sending any byte over the NAND bus.
+ * i.e.,
+ * NAND power down command or reset command w/o R/B# status checking.
+ */
+ nand_select_target(chip, 0);
+ nand_power_down_op(chip);
+ /* The minimum of a recovery time tRDP is 35 us */
+ usleep_range(35, 100);
+ nand_deselect_target(chip);
+}
+
+static void macronix_nand_deep_power_down_support(struct nand_chip *chip)
+{
+ int i;
+ static const char * const deep_power_down_dev[] = {
+ "MX30UF1G28AD",
+ "MX30UF2G28AD",
+ "MX30UF4G28AD",
+ };
+
+ i = match_string(deep_power_down_dev, ARRAY_SIZE(deep_power_down_dev),
+ chip->parameters.model);
+ if (i < 0)
+ return;
+
+ chip->suspend = mxic_nand_suspend;
+ chip->resume = mxic_nand_resume;
+}
+
static int macronix_nand_init(struct nand_chip *chip)
{
if (nand_is_slc(chip))
@@ -98,6 +171,7 @@ static int macronix_nand_init(struct nand_chip *chip)

macronix_nand_fix_broken_get_timings(chip);
macronix_nand_onfi_init(chip);
+ macronix_nand_deep_power_down_support(chip);

return 0;
}
--
1.9.1