[RFC PATCH 5/6] mtd: spi-nor: Use the spi_mem_xx() API

Boris Brezillon
2018-02-05T23:22:13Z

From: Boris Brezillon <boris.brezillon@free-electrons.com>

The spi_mem_xxx() API has been introduced to replace the
spi_flash_read() one. Make use of it so we can get rid of
spi_flash_read().

Note that using spi_mem_xx() also simplifies the code because this API
takes care of using the regular spi_sync() interface when the optimized
->mem_ops interface is not implemented by the controller.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
drivers/mtd/devices/m25p80.c | 240 ++++++++++++++++---------------------------
1 file changed, 88 insertions(+), 152 deletions(-)

diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index a4e18f6aaa33..3b17425d5e6f 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -29,7 +29,7 @@

#define MAX_CMD_SIZE 6
struct m25p {
- struct spi_device *spi;
+ struct spi_mem *spimem;
struct spi_nor spi_nor;
u8 command[MAX_CMD_SIZE];
};
@@ -37,97 +37,80 @@ struct m25p {
static int m25p80_read_reg(struct spi_nor *nor, u8 code, u8 *val, int len)
{
struct m25p *flash = nor->priv;
- struct spi_device *spi = flash->spi;
+ struct spi_mem_op op = SPI_MEM_OP(SPI_MEM_OP_CMD(code, 1),
+ SPI_MEM_OP_NO_ADDRS,
+ SPI_MEM_OP_NO_DUMMY,
+ SPI_MEM_OP_DATA_IN(len, val, 1));
int ret;

- ret = spi_write_then_read(spi, &code, 1, val, len);
+ ret = spi_mem_exec_op(flash->spimem, &op);
if (ret < 0)
- dev_err(&spi->dev, "error %d reading %x\n", ret, code);
+ dev_err(&flash->spimem->spi->dev, "error %d reading %x\n", ret,
+ code);

return ret;
}

-static void m25p_addr2cmd(struct spi_nor *nor, unsigned int addr, u8 *cmd)
+static void m25p_offs2addr(struct spi_nor *nor, unsigned int offs, u8 *addrs)
{
- /* opcode is in cmd[0] */
- cmd[1] = addr >> (nor->addr_width * 8 - 8);
- cmd[2] = addr >> (nor->addr_width * 8 - 16);
- cmd[3] = addr >> (nor->addr_width * 8 - 24);
- cmd[4] = addr >> (nor->addr_width * 8 - 32);
-}
-
-static int m25p_cmdsz(struct spi_nor *nor)
-{
- return 1 + nor->addr_width;
+ addrs[0] = offs >> (nor->addr_width * 8 - 8);
+ addrs[1] = offs >> (nor->addr_width * 8 - 16);
+ addrs[2] = offs >> (nor->addr_width * 8 - 24);
+ addrs[3] = offs >> (nor->addr_width * 8 - 32);
}

static int m25p80_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
{
struct m25p *flash = nor->priv;
- struct spi_device *spi = flash->spi;
+ struct spi_mem_op op = SPI_MEM_OP(SPI_MEM_OP_CMD(opcode, 1),
+ SPI_MEM_OP_NO_ADDRS,
+ SPI_MEM_OP_NO_DUMMY,
+ SPI_MEM_OP_DATA_OUT(len, buf, 1));

- flash->command[0] = opcode;
- if (buf)
- memcpy(&flash->command[1], buf, len);
-
- return spi_write(spi, flash->command, len + 1);
+ return spi_mem_exec_op(flash->spimem, &op);
}

static ssize_t m25p80_write(struct spi_nor *nor, loff_t to, size_t len,
const u_char *buf)
{
struct m25p *flash = nor->priv;
- struct spi_device *spi = flash->spi;
- unsigned int inst_nbits, addr_nbits, data_nbits, data_idx;
- struct spi_transfer t[3] = {};
- struct spi_message m;
- int cmd_sz = m25p_cmdsz(nor);
- ssize_t ret;
+ u8 addrs[4];
+ struct spi_mem_op op =
+ SPI_MEM_OP(SPI_MEM_OP_CMD(nor->program_opcode, 1),
+ SPI_MEM_OP_ADDRS(nor->addr_width, addrs, 1),
+ SPI_MEM_OP_DUMMY(0, 1),
+ SPI_MEM_OP_DATA_OUT(len, buf, 1));
+ size_t remaining = len;
+ int ret;

/* get transfer protocols. */
- inst_nbits = spi_nor_get_protocol_inst_nbits(nor->write_proto);
- addr_nbits = spi_nor_get_protocol_addr_nbits(nor->write_proto);
- data_nbits = spi_nor_get_protocol_data_nbits(nor->write_proto);
-
- spi_message_init(&m);
+ op.cmd.buswidth = spi_nor_get_protocol_inst_nbits(nor->write_proto);
+ op.addr.buswidth = spi_nor_get_protocol_addr_nbits(nor->write_proto);
+ op.dummy.buswidth = op.addr.buswidth;
+ op.data.buswidth = spi_nor_get_protocol_data_nbits(nor->write_proto);

if (nor->program_opcode == SPINOR_OP_AAI_WP && nor->sst_write_second)
- cmd_sz = 1;
-
- flash->command[0] = nor->program_opcode;
- m25p_addr2cmd(nor, to, flash->command);
+ op.addr.nbytes = 0;

- t[0].tx_buf = flash->command;
- t[0].tx_nbits = inst_nbits;
- t[0].len = cmd_sz;
- spi_message_add_tail(&t[0], &m);
+ while (remaining) {
+ if (op.addr.nbytes)
+ m25p_offs2addr(nor, to, addrs);

- /* split the op code and address bytes into two transfers if needed. */
- data_idx = 1;
- if (addr_nbits != inst_nbits) {
- t[0].len = 1;
+ op.data.nbytes = remaining < UINT_MAX ? remaining : UINT_MAX;
+ ret = spi_mem_adjust_op_size(flash->spimem, &op);
+ if (ret)
+ return ret;

- t[1].tx_buf = &flash->command[1];
- t[1].tx_nbits = addr_nbits;
- t[1].len = cmd_sz - 1;
- spi_message_add_tail(&t[1], &m);
+ ret = spi_mem_exec_op(flash->spimem, &op);
+ if (ret)
+ return ret;

- data_idx = 2;
+ to += op.data.nbytes;
+ remaining -= op.data.nbytes;
+ op.data.buf.out += op.data.nbytes;
}

- t[data_idx].tx_buf = buf;
- t[data_idx].tx_nbits = data_nbits;
- t[data_idx].len = len;
- spi_message_add_tail(&t[data_idx], &m);
-
- ret = spi_sync(spi, &m);
- if (ret)
- return ret;
-
- ret = m.actual_length - cmd_sz;
- if (ret < 0)
- return -EIO;
- return ret;
+ return len;
}

/*
@@ -138,92 +121,42 @@ static ssize_t m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
u_char *buf)
{
struct m25p *flash = nor->priv;
- struct spi_device *spi = flash->spi;
- unsigned int inst_nbits, addr_nbits, data_nbits, data_idx;
- struct spi_transfer t[3];
- struct spi_message m;
- unsigned int dummy = nor->read_dummy;
- ssize_t ret;
- int cmd_sz;
+ u8 addrs[4];
+ struct spi_mem_op op =
+ SPI_MEM_OP(SPI_MEM_OP_CMD(nor->read_opcode, 1),
+ SPI_MEM_OP_ADDRS(nor->addr_width, addrs, 1),
+ SPI_MEM_OP_DUMMY(nor->read_dummy, 1),
+ SPI_MEM_OP_DATA_OUT(len, buf, 1));
+ size_t remaining = len;
+ int ret;

/* get transfer protocols. */
- inst_nbits = spi_nor_get_protocol_inst_nbits(nor->read_proto);
- addr_nbits = spi_nor_get_protocol_addr_nbits(nor->read_proto);
- data_nbits = spi_nor_get_protocol_data_nbits(nor->read_proto);
+ op.cmd.buswidth = spi_nor_get_protocol_inst_nbits(nor->read_proto);
+ op.addr.buswidth = spi_nor_get_protocol_addr_nbits(nor->read_proto);
+ op.dummy.buswidth = op.addr.buswidth;
+ op.data.buswidth = spi_nor_get_protocol_data_nbits(nor->read_proto);

/* convert the dummy cycles to the number of bytes */
- dummy = (dummy * addr_nbits) / 8;
-
- if (spi_flash_read_supported(spi)) {
- struct spi_flash_read_message msg;
+ op.dummy.nbytes = (nor->read_dummy * op.dummy.buswidth) / 8;

- memset(&msg, 0, sizeof(msg));
+ while (remaining) {
+ m25p_offs2addr(nor, from, addrs);

- msg.buf = buf;
- msg.from = from;
- msg.len = len;
- msg.read_opcode = nor->read_opcode;
- msg.addr_width = nor->addr_width;
- msg.dummy_bytes = dummy;
- msg.opcode_nbits = inst_nbits;
- msg.addr_nbits = addr_nbits;
- msg.data_nbits = data_nbits;
-
- ret = spi_flash_read(spi, &msg);
- if (ret < 0)
+ op.data.nbytes = remaining < UINT_MAX ? remaining : UINT_MAX;
+ ret = spi_mem_adjust_op_size(flash->spimem, &op);
+ if (ret)
return ret;
- return msg.retlen;
- }
-
- spi_message_init(&m);
- memset(t, 0, (sizeof t));
-
- flash->command[0] = nor->read_opcode;
- m25p_addr2cmd(nor, from, flash->command);
-
- t[0].tx_buf = flash->command;
- t[0].tx_nbits = inst_nbits;
- t[0].len = m25p_cmdsz(nor) + dummy;
- spi_message_add_tail(&t[0], &m);
-
- /*
- * Set all dummy/mode cycle bits to avoid sending some manufacturer
- * specific pattern, which might make the memory enter its Continuous
- * Read mode by mistake.
- * Based on the different mode cycle bit patterns listed and described
- * in the JESD216B specification, the 0xff value works for all memories
- * and all manufacturers.
- */
- cmd_sz = t[0].len;
- memset(flash->command + cmd_sz - dummy, 0xff, dummy);

- /* split the op code and address bytes into two transfers if needed. */
- data_idx = 1;
- if (addr_nbits != inst_nbits) {
- t[0].len = 1;
-
- t[1].tx_buf = &flash->command[1];
- t[1].tx_nbits = addr_nbits;
- t[1].len = cmd_sz - 1;
- spi_message_add_tail(&t[1], &m);
+ ret = spi_mem_exec_op(flash->spimem, &op);
+ if (ret)
+ return ret;

- data_idx = 2;
+ from += op.data.nbytes;
+ remaining -= op.data.nbytes;
+ op.data.buf.in += op.data.nbytes;
}

- t[data_idx].rx_buf = buf;
- t[data_idx].rx_nbits = data_nbits;
- t[data_idx].len = min3(len, spi_max_transfer_size(spi),
- spi_max_message_size(spi) - cmd_sz);
- spi_message_add_tail(&t[data_idx], &m);
-
- ret = spi_sync(spi, &m);
- if (ret)
- return ret;
-
- ret = m.actual_length - cmd_sz;
- if (ret < 0)
- return -EIO;
- return ret;
+ return len;
}

/*
@@ -231,8 +164,9 @@ static ssize_t m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
* matches what the READ command supports, at least until this driver
* understands FAST_READ (for clocks over 25 MHz).
*/
-static int m25p_probe(struct spi_device *spi)
+static int m25p_probe(struct spi_mem *spimem)
{
+ struct spi_device *spi = spimem->spi;
struct flash_platform_data *data;
struct m25p *flash;
struct spi_nor *nor;
@@ -244,9 +178,9 @@ static int m25p_probe(struct spi_device *spi)
char *flash_name;
int ret;

- data = dev_get_platdata(&spi->dev);
+ data = dev_get_platdata(&spimem->spi->dev);

- flash = devm_kzalloc(&spi->dev, sizeof(*flash), GFP_KERNEL);
+ flash = devm_kzalloc(&spimem->spi->dev, sizeof(*flash), GFP_KERNEL);
if (!flash)
return -ENOMEM;

@@ -258,12 +192,12 @@ static int m25p_probe(struct spi_device *spi)
nor->write_reg = m25p80_write_reg;
nor->read_reg = m25p80_read_reg;

- nor->dev = &spi->dev;
+ nor->dev = &spimem->spi->dev;
spi_nor_set_flash_node(nor, spi->dev.of_node);
nor->priv = flash;

spi_set_drvdata(spi, flash);
- flash->spi = spi;
+ flash->spimem = spimem;

if (spi->mode & SPI_RX_QUAD) {
hwcaps.mask |= SNOR_HWCAPS_READ_1_1_4;
@@ -303,9 +237,9 @@ static int m25p_probe(struct spi_device *spi)
}

-static int m25p_remove(struct spi_device *spi)
+static int m25p_remove(struct spi_mem *spimem)
{
- struct m25p *flash = spi_get_drvdata(spi);
+ struct m25p *flash = spi_mem_get_drvdata(spimem);

spi_nor_restore(&flash->spi_nor);

@@ -313,9 +247,9 @@ static int m25p_remove(struct spi_device *spi)
return mtd_device_unregister(&flash->spi_nor.mtd);
}

-static void m25p_shutdown(struct spi_device *spi)
+static void m25p_shutdown(struct spi_mem *spimem)
{
- struct m25p *flash = spi_get_drvdata(spi);
+ struct m25p *flash = spi_mem_get_drvdata(spimem);

spi_nor_restore(&flash->spi_nor);
}
@@ -386,12 +320,14 @@ static const struct of_device_id m25p_of_table[] = {
};
MODULE_DEVICE_TABLE(of, m25p_of_table);

-static struct spi_driver m25p80_driver = {
- .driver = {
- .name = "m25p80",
- .of_match_table = m25p_of_table,
+static struct spi_mem_driver m25p80_driver = {
+ .spidrv = {
+ .driver = {
+ .name = "m25p80",
+ .of_match_table = m25p_of_table,
+ },
+ .id_table = m25p_ids,
},
- .id_table = m25p_ids,
.probe = m25p_probe,
.remove = m25p_remove,
.shutdown = m25p_shutdown,
@@ -402,7 +338,7 @@ static struct spi_driver m25p80_driver = {
*/
};

-module_spi_driver(m25p80_driver);
+module_spi_mem_driver(m25p80_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Mike Lavender");
--
2.14.1