On Thu, 25 May 2017 11:49:16 +1200 Chris Packham <[email protected]> wrote:
> The mchp23lcv1024 is similar to the mchp23k256, the differences (from a > software point of view) are the capacity of the chip and the size of the > addresses used. > > There is no way to detect the specific chip so we must be told via a > Device Tree or default to mchp23k256 when device tree is not used. > > Signed-off-by: Chris Packham <[email protected]> > Reviewed-by: Andrew Lunn <[email protected]> Acked-by: Boris Brezillon <[email protected]> > --- > Changes in v2: > - fix formatting in switch statement > - add support for 24-bit addressing > Changes in v3: > - None > Changes in v4: > - reword commit message (thanks Andrew) > - introduce mchp23_caps struct (thanks Boris) > > .../bindings/mtd/microchip,mchp23k256.txt | 2 +- > drivers/mtd/devices/mchp23k256.c | 66 > ++++++++++++++++++---- > 2 files changed, 57 insertions(+), 11 deletions(-) > > diff --git a/Documentation/devicetree/bindings/mtd/microchip,mchp23k256.txt > b/Documentation/devicetree/bindings/mtd/microchip,mchp23k256.txt > index 25e5ad38b0f0..7328eb92a03c 100644 > --- a/Documentation/devicetree/bindings/mtd/microchip,mchp23k256.txt > +++ b/Documentation/devicetree/bindings/mtd/microchip,mchp23k256.txt > @@ -3,7 +3,7 @@ > Required properties: > - #address-cells, #size-cells : Must be present if the device has sub-nodes > representing partitions. > -- compatible : Must be "microchip,mchp23k256" > +- compatible : Must be one of "microchip,mchp23k256" or > "microchip,mchp23lcv1024" > - reg : Chip-Select number > - spi-max-frequency : Maximum frequency of the SPI bus the chip can operate > at > > diff --git a/drivers/mtd/devices/mchp23k256.c > b/drivers/mtd/devices/mchp23k256.c > index 3e5feb454644..8956b7dcc984 100644 > --- a/drivers/mtd/devices/mchp23k256.c > +++ b/drivers/mtd/devices/mchp23k256.c > @@ -21,10 +21,18 @@ > #include <linux/spi/spi.h> > #include <linux/of_device.h> > > +#define MAX_CMD_SIZE 4 > + > +struct mchp23_caps { > + u8 addr_width; > + unsigned int size; > +}; > + > struct mchp23k256_flash { > struct spi_device *spi; > struct mutex lock; > struct mtd_info mtd; > + const struct mchp23_caps *caps; > }; > > #define MCHP23K256_CMD_WRITE_STATUS 0x01 > @@ -34,22 +42,40 @@ struct mchp23k256_flash { > > #define to_mchp23k256_flash(x) container_of(x, struct mchp23k256_flash, mtd) > > +static void mchp23k256_addr2cmd(struct mchp23k256_flash *flash, > + unsigned int addr, u8 *cmd) > +{ > + int i; > + > + /* > + * Address is sent in big endian (MSB first) and we skip > + * the first entry of the cmd array which contains the cmd > + * opcode. > + */ > + for (i = flash->caps->addr_width; i > 0; i--, addr >>= 8) > + cmd[i] = addr; > +} > + > +static int mchp23k256_cmdsz(struct mchp23k256_flash *flash) > +{ > + return 1 + flash->caps->addr_width; > +} > + > static int mchp23k256_write(struct mtd_info *mtd, loff_t to, size_t len, > size_t *retlen, const unsigned char *buf) > { > struct mchp23k256_flash *flash = to_mchp23k256_flash(mtd); > struct spi_transfer transfer[2] = {}; > struct spi_message message; > - unsigned char command[3]; > + unsigned char command[MAX_CMD_SIZE]; > > spi_message_init(&message); > > command[0] = MCHP23K256_CMD_WRITE; > - command[1] = to >> 8; > - command[2] = to; > + mchp23k256_addr2cmd(flash, to, command); > > transfer[0].tx_buf = command; > - transfer[0].len = sizeof(command); > + transfer[0].len = mchp23k256_cmdsz(flash); > spi_message_add_tail(&transfer[0], &message); > > transfer[1].tx_buf = buf; > @@ -73,17 +99,16 @@ static int mchp23k256_read(struct mtd_info *mtd, loff_t > from, size_t len, > struct mchp23k256_flash *flash = to_mchp23k256_flash(mtd); > struct spi_transfer transfer[2] = {}; > struct spi_message message; > - unsigned char command[3]; > + unsigned char command[MAX_CMD_SIZE]; > > spi_message_init(&message); > > memset(&transfer, 0, sizeof(transfer)); > command[0] = MCHP23K256_CMD_READ; > - command[1] = from >> 8; > - command[2] = from; > + mchp23k256_addr2cmd(flash, from, command); > > transfer[0].tx_buf = command; > - transfer[0].len = sizeof(command); > + transfer[0].len = mchp23k256_cmdsz(flash); > spi_message_add_tail(&transfer[0], &message); > > transfer[1].rx_buf = buf; > @@ -123,6 +148,16 @@ static int mchp23k256_set_mode(struct spi_device *spi) > return spi_sync(spi, &message); > } > > +static const struct mchp23_caps mchp23k256_caps = { > + .size = SZ_32K, > + .addr_width = 2, > +}; > + > +static const struct mchp23_caps mchp23lcv1024_caps = { > + .size = SZ_128K, > + .addr_width = 3, > +}; > + > static int mchp23k256_probe(struct spi_device *spi) > { > struct mchp23k256_flash *flash; > @@ -143,12 +178,16 @@ static int mchp23k256_probe(struct spi_device *spi) > > data = dev_get_platdata(&spi->dev); > > + flash->caps = of_device_get_match_data(&spi->dev); > + if (!flash->caps) > + flash->caps = &mchp23k256_caps; > + > mtd_set_of_node(&flash->mtd, spi->dev.of_node); > flash->mtd.dev.parent = &spi->dev; > flash->mtd.type = MTD_RAM; > flash->mtd.flags = MTD_CAP_RAM; > flash->mtd.writesize = 1; > - flash->mtd.size = SZ_32K; > + flash->mtd.size = flash->caps->size; > flash->mtd._read = mchp23k256_read; > flash->mtd._write = mchp23k256_write; > > @@ -168,7 +207,14 @@ static int mchp23k256_remove(struct spi_device *spi) > } > > static const struct of_device_id mchp23k256_of_table[] = { > - { .compatible = "microchip,mchp23k256" }, > + { > + .compatible = "microchip,mchp23k256", > + .data = &mchp23k256_caps, > + }, > + { > + .compatible = "microchip,mchp23lcv1024", > + .data = &mchp23lcv1024_caps, > + }, > {} > }; > MODULE_DEVICE_TABLE(of, mchp23k256_of_table);
