[RFC PATCH] mtd: rawnand: ams-delta: use ->exec_op()

Janusz Krzysztofik
2018-10-03T11:59:22Z

Replace legacy callbacks with ->select_chip() and ->exec_op().

Implementation of NAND_OP_WAITRDY_INSTR has been based on legacy
nand_wait_ready(), otherwise that function would probabaly have to be
reimplemented inside the driver. Hence, legacy callback ->dev_ready()
is still used.

Use of IO_ADDR_R and IO_ADDR_W legacy structure members will be dropped
later, as soon as the driver is converted to use GPIO API for data I/O.

Suggested-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
---
Hi,

I've not tested the change on hardware yet as I'm not sure if:
- handling of NCE limited to that inside ->select_chip() is
sufficient,
- releasing ALE / CLE immediately after ams_delta_write_buf() is
correct.
Please advise before I break my test hardware :-).

Thanks,
Janusz

drivers/mtd/nand/raw/ams-delta.c | 83 +++++++++++++++++++++++++---------------
1 file changed, 52 insertions(+), 31 deletions(-)

diff --git a/drivers/mtd/nand/raw/ams-delta.c b/drivers/mtd/nand/raw/ams-delta.c
index 5ba180a291eb..90c283a2c1b7 100644
--- a/drivers/mtd/nand/raw/ams-delta.c
+++ b/drivers/mtd/nand/raw/ams-delta.c
@@ -124,46 +124,69 @@ static void ams_delta_read_buf(struct nand_chip *this, u_char *buf, int len)
buf[i] = ams_delta_io_read(priv);
}

-static u_char ams_delta_read_byte(struct nand_chip *this)
+static int ams_delta_nand_ready(struct nand_chip *this)
{
- u_char res;
-
- ams_delta_read_buf(this, &res, 1);
+ struct ams_delta_nand *priv = nand_get_controller_data(this);

- return res;
+ return gpiod_get_value(priv->gpiod_rdy);
}

-/*
- * Command control function
- *
- * ctrl:
- * NAND_NCE: bit 0 -> bit 2
- * NAND_CLE: bit 1 -> bit 7
- * NAND_ALE: bit 2 -> bit 6
- */
-static void ams_delta_hwcontrol(struct nand_chip *this, int cmd,
- unsigned int ctrl)
+static void ams_delta_select_chip(struct nand_chip *this, int n)
{
struct ams_delta_nand *priv = nand_get_controller_data(this);

- if (ctrl & NAND_CTRL_CHANGE) {
- gpiod_set_value(priv->gpiod_nce, !(ctrl & NAND_NCE));
- gpiod_set_value(priv->gpiod_cle, !!(ctrl & NAND_CLE));
- gpiod_set_value(priv->gpiod_ale, !!(ctrl & NAND_ALE));
- }
-
- if (cmd != NAND_CMD_NONE) {
- u_char byte = cmd;
+ if (n > 0)
+ return;

- ams_delta_write_buf(this, &byte, 1);
- }
+ gpiod_set_value(priv->gpiod_nce, n < 0);
}

-static int ams_delta_nand_ready(struct nand_chip *this)
+static int ams_delta_exec_op(struct nand_chip *this,
+ const struct nand_operation *op, bool check_only)
{
struct ams_delta_nand *priv = nand_get_controller_data(this);
+ const struct nand_op_instr *instr;
+ int i;

- return gpiod_get_value(priv->gpiod_rdy);
+ for (i = 0; i < op->ninstrs; i++) {
+ instr = &op->instrs[i];
+
+ switch (instr->type) {
+ case NAND_OP_CMD_INSTR:
+ gpiod_set_value(priv->gpiod_cle, 1);
+ ams_delta_write_buf(this, &instr->ctx.cmd.opcode, 1);
+ gpiod_set_value(priv->gpiod_cle, 0);
+ break;
+
+ case NAND_OP_ADDR_INSTR:
+ gpiod_set_value(priv->gpiod_ale, 1);
+ ams_delta_write_buf(this, instr->ctx.addr.addrs,
+ instr->ctx.addr.naddrs);
+ gpiod_set_value(priv->gpiod_ale, 0);
+ break;
+
+ case NAND_OP_DATA_IN_INSTR:
+ ams_delta_read_buf(this, instr->ctx.data.buf.in,
+ instr->ctx.data.len);
+ break;
+
+ case NAND_OP_DATA_OUT_INSTR:
+ ams_delta_write_buf(this, instr->ctx.data.buf.out,
+ instr->ctx.data.len);
+ break;
+
+ case NAND_OP_WAITRDY_INSTR:
+ if (this->legacy.dev_ready) {
+ nand_wait_ready(this);
+ break;
+ }
+
+ return nand_soft_waitrdy(this,
+ instr->ctx.waitrdy.timeout_ms);
+ }
+ }
+
+ return 0;
}

@@ -213,10 +236,8 @@ static int ams_delta_init(struct platform_device *pdev)
/* Set address of NAND IO lines */
this->legacy.IO_ADDR_R = io_base + OMAP_MPUIO_INPUT_LATCH;
this->legacy.IO_ADDR_W = io_base + OMAP_MPUIO_OUTPUT;
- this->legacy.read_byte = ams_delta_read_byte;
- this->legacy.write_buf = ams_delta_write_buf;
- this->legacy.read_buf = ams_delta_read_buf;
- this->legacy.cmd_ctrl = ams_delta_hwcontrol;
+ this->select_chip = ams_delta_select_chip;
+ this->exec_op = ams_delta_exec_op;

priv->gpiod_rdy = devm_gpiod_get_optional(&pdev->dev, "rdy", GPIOD_IN);
if (IS_ERR(priv->gpiod_rdy)) {
--
2.16.4