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mtd: spi-nor: Use the spi_mem_xx() API
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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@bootlin.com>
Reviewed-by: Frieder Schrempf <frieder.schrempf@exceet.de>
Tested-by: Frieder Schrempf <frieder.schrempf@exceet.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
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Boris Brezillon authored and broonie committed May 11, 2018
1 parent b95cb39 commit 4120f8d
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Showing 2 changed files with 80 additions and 157 deletions.
1 change: 1 addition & 0 deletions drivers/mtd/devices/Kconfig
View file
Original file line number Diff line number Diff line change
Expand Up @@ -81,6 +81,7 @@ config MTD_DATAFLASH_OTP
config MTD_M25P80
tristate "Support most SPI Flash chips (AT26DF, M25P, W25X, ...)"
depends on SPI_MASTER && MTD_SPI_NOR
select SPI_MEM
help
This enables access to most modern SPI flash chips, used for
program and data storage. Series supported include Atmel AT26DF,
Expand Down
236 changes: 79 additions & 157 deletions drivers/mtd/devices/m25p80.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -24,110 +24,82 @@
#include <linux/mtd/partitions.h>

#include <linux/spi/spi.h>
#include <linux/spi/spi-mem.h>
#include <linux/spi/flash.h>
#include <linux/mtd/spi-nor.h>

#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];
};

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_ADDR,
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)
{
/* 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;
}

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;

flash->command[0] = opcode;
if (buf)
memcpy(&flash->command[1], buf, len);
struct spi_mem_op op = SPI_MEM_OP(SPI_MEM_OP_CMD(opcode, 1),
SPI_MEM_OP_NO_ADDR,
SPI_MEM_OP_NO_DUMMY,
SPI_MEM_OP_DATA_OUT(len, buf, 1));

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;
struct spi_mem_op op =
SPI_MEM_OP(SPI_MEM_OP_CMD(nor->program_opcode, 1),
SPI_MEM_OP_ADDR(nor->addr_width, to, 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);

/* split the op code and address bytes into two transfers if needed. */
data_idx = 1;
if (addr_nbits != inst_nbits) {
t[0].len = 1;
while (remaining) {
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;
op.addr.val += 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;
}

/*
Expand All @@ -138,101 +110,49 @@ 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;
struct spi_mem_op op =
SPI_MEM_OP(SPI_MEM_OP_CMD(nor->read_opcode, 1),
SPI_MEM_OP_ADDR(nor->addr_width, from, 1),
SPI_MEM_OP_DUMMY(nor->read_dummy, 1),
SPI_MEM_OP_DATA_IN(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;

memset(&msg, 0, sizeof(msg));
op.dummy.nbytes = (nor->read_dummy * op.dummy.buswidth) / 8;

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)
while (remaining) {
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;
op.addr.val += 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;
}

/*
* board specific setup should have ensured the SPI clock used here
* 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;
Expand All @@ -244,9 +164,9 @@ 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;

Expand All @@ -258,12 +178,12 @@ 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;
Expand Down Expand Up @@ -303,19 +223,19 @@ 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);

/* Clean up MTD stuff. */
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);
}
Expand Down Expand Up @@ -386,12 +306,14 @@ 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,
Expand All @@ -402,7 +324,7 @@ static struct spi_driver m25p80_driver = {
*/
};

module_spi_driver(m25p80_driver);
module_spi_mem_driver(m25p80_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Mike Lavender");
Expand Down

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