mtd: spi-nor: Use the spi_mem_xx() API

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>

2 files changed, 80 insertions, 157 deletions

diff --git a/drivers/mtd/devices/Kconfig b/drivers/mtd/devices/Kconfig
index 6def5445e03e..57b02c4b3f63 100644
--- a/drivers/mtd/devices/Kconfig
+++ b/drivers/mtd/devices/Kconfig
@@ -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,
diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index a4e18f6aaa33..3dc022d3b53e 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -24,12 +24,13 @@
 #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];
 };
@@ -37,97 +38,68 @@ 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_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;
 }
 
 /*
@@ -138,92 +110,39 @@ 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;
 }
 
 /*
@@ -231,8 +150,9 @@ 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 +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;
 
@@ -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;
@@ -303,9 +223,9 @@ 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 +233,9 @@ 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 +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,
@@ -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");