Bump, do you think we can get this into 3.7 please?
> Add DT property "m25p,fast-read" that signalises the particular > chip supports "fast read" opcode. > > Signed-off-by: Marek Vasut <[email protected]> > Cc: Artem Bityutskiy <[email protected]> > Cc: David Woodhouse <[email protected]> > --- > Documentation/devicetree/bindings/mtd/m25p80.txt | 29 ++++++++++++++++++ > drivers/mtd/devices/m25p80.c | 34 > +++++++++++++--------- 2 files changed, 50 insertions(+), 13 deletions(-) > create mode 100644 Documentation/devicetree/bindings/mtd/m25p80.txt > > V2: Add documentation for the DT property. > V3: Use of_property_get_bool() instead of of_find_property(). > V4: Adjust the documentation's "compatible:" section, make it not > Linux-specific, but keep the reference to Linux's list of > supported devices. Also, use the default name, spansion,m25p80 > in the example. > V5: Enclose of_property_read_bool() into CONFIG_OF for systems that do not > use OF / Device Tree . > > diff --git a/Documentation/devicetree/bindings/mtd/m25p80.txt > b/Documentation/devicetree/bindings/mtd/m25p80.txt new file mode 100644 > index 0000000..701bb58 > --- /dev/null > +++ b/Documentation/devicetree/bindings/mtd/m25p80.txt > @@ -0,0 +1,29 @@ > +* MTD SPI driver for ST M25Pxx (and similar) serial flash chips > + > +Required properties: > +- #address-cells, #size-cells : Must be present if the device has > sub-nodes + representing partitions. > +- compatible : Should be the manufacturer and the name of the chip. Bear > in mind + the DT binding is not Linux-only, but in case of > Linux, see the + "m25p_ids" table in > drivers/mtd/devices/m25p80.c for the list of + supported > chips. > +- reg : Chip-Select number > +- spi-max-frequency : Maximum frequency of the SPI bus the chip can > operate at + > +Optional properties: > +- m25p,fast-read : Use the "fast read" opcode to read data from the chip > instead + of the usual "read" opcode. This opcode isn > not supported by + all chips and support for it can not > be detected at runtime. + Refer to your chips' datasheet > to check if this is supported + by your chip. > + > +Example: > + > + flash: m25p80@0 { > + #address-cells = <1>; > + #size-cells = <1>; > + compatible = "spansion,m25p80"; > + reg = <0>; > + spi-max-frequency = <40000000>; > + m25p,fast-read; > + }; > diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c > index d16f75c..c433051 100644 > --- a/drivers/mtd/devices/m25p80.c > +++ b/drivers/mtd/devices/m25p80.c > @@ -73,14 +73,6 @@ > #define MAX_READY_WAIT_JIFFIES (40 * HZ) /* M25P16 specs 40s max chip > erase */ #define MAX_CMD_SIZE 5 > > -#ifdef CONFIG_M25PXX_USE_FAST_READ > -#define OPCODE_READ OPCODE_FAST_READ > -#define FAST_READ_DUMMY_BYTE 1 > -#else > -#define OPCODE_READ OPCODE_NORM_READ > -#define FAST_READ_DUMMY_BYTE 0 > -#endif > - > #define JEDEC_MFR(_jedec_id) ((_jedec_id) >> 16) > > /************************************************************************* > ***/ @@ -93,6 +85,7 @@ struct m25p { > u16 addr_width; > u8 erase_opcode; > u8 *command; > + bool fast_read; > }; > > static inline struct m25p *mtd_to_m25p(struct mtd_info *mtd) > @@ -342,6 +335,7 @@ static int m25p80_read(struct mtd_info *mtd, loff_t > from, size_t len, struct m25p *flash = mtd_to_m25p(mtd); > struct spi_transfer t[2]; > struct spi_message m; > + uint8_t opcode; > > pr_debug("%s: %s from 0x%08x, len %zd\n", dev_name(&flash->spi->dev), > __func__, (u32)from, len); > @@ -354,7 +348,7 @@ static int m25p80_read(struct mtd_info *mtd, loff_t > from, size_t len, * Should add 1 byte DUMMY_BYTE. > */ > t[0].tx_buf = flash->command; > - t[0].len = m25p_cmdsz(flash) + FAST_READ_DUMMY_BYTE; > + t[0].len = m25p_cmdsz(flash) + (flash->fast_read ? 1 : 0); > spi_message_add_tail(&t[0], &m); > > t[1].rx_buf = buf; > @@ -376,12 +370,14 @@ static int m25p80_read(struct mtd_info *mtd, loff_t > from, size_t len, */ > > /* Set up the write data buffer. */ > - flash->command[0] = OPCODE_READ; > + opcode = flash->fast_read ? OPCODE_FAST_READ : OPCODE_NORM_READ; > + flash->command[0] = opcode; > m25p_addr2cmd(flash, from, flash->command); > > spi_sync(flash->spi, &m); > > - *retlen = m.actual_length - m25p_cmdsz(flash) - FAST_READ_DUMMY_BYTE; > + *retlen = m.actual_length - m25p_cmdsz(flash) - > + (flash->fast_read ? 1 : 0); > > mutex_unlock(&flash->lock); > > @@ -804,9 +800,10 @@ static int __devinit m25p_probe(struct spi_device > *spi) struct flash_info *info; > unsigned i; > struct mtd_part_parser_data ppdata; > + struct device_node *np = spi->dev.of_node; > > #ifdef CONFIG_MTD_OF_PARTS > - if (!of_device_is_available(spi->dev.of_node)) > + if (!of_device_is_available(np)) > return -ENODEV; > #endif > > @@ -858,7 +855,8 @@ static int __devinit m25p_probe(struct spi_device *spi) > flash = kzalloc(sizeof *flash, GFP_KERNEL); > if (!flash) > return -ENOMEM; > - flash->command = kmalloc(MAX_CMD_SIZE + FAST_READ_DUMMY_BYTE, > GFP_KERNEL); + flash->command = kmalloc(MAX_CMD_SIZE + (flash- >fast_read ? > 1 : 0), + GFP_KERNEL); > if (!flash->command) { > kfree(flash); > return -ENOMEM; > @@ -915,6 +913,16 @@ static int __devinit m25p_probe(struct spi_device > *spi) flash->page_size = info->page_size; > flash->mtd.writebufsize = flash->page_size; > > + flash->fast_read = false; > +#ifdef CONFIG_OF > + if (np && of_property_read_bool(np, "m25p,fast-read")) > + flash->fast_read = true; > +#endif > + > +#ifdef CONFIG_M25PXX_USE_FAST_READ > + flash->fast_read = true; > +#endif > + > if (info->addr_width) > flash->addr_width = info->addr_width; > else { _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
