From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pratyush Yadav Subject: Re: [PATCH v2 04/11] spi: spi-mem: allow specifying a command's extension Date: Fri, 28 Feb 2020 15:11:42 +0530 Message-ID: <20200228094142.436fjee5fb7w6pd2@ti.com> References: <20200226093703.19765-1-p.yadav@ti.com> <20200226093703.19765-5-p.yadav@ti.com> <20200227174406.66bf6f84@collabora.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Mark Rutland , devicetree@vger.kernel.org, Vignesh Raghavendra , Tudor Ambarus , Richard Weinberger , Sekhar Nori , linux-kernel@vger.kernel.org, Rob Herring , linux-spi@vger.kernel.org, Mark Brown , linux-mtd@lists.infradead.org, Miquel Raynal To: Boris Brezillon Return-path: Content-Disposition: inline In-Reply-To: <20200227174406.66bf6f84@collabora.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-mtd" Errors-To: linux-mtd-bounces+gldm-linux-mtd-36=m.gmane-mx.org@lists.infradead.org List-Id: linux-spi.vger.kernel.org On 27/02/20 05:44PM, Boris Brezillon wrote: > On Wed, 26 Feb 2020 15:06:56 +0530 > Pratyush Yadav wrote: > > > In xSPI mode, flashes expect 2-byte opcodes. The second byte is called > > the "command extension". There can be 3 types of extensions in xSPI: > > repeat, invert, and hex. When the extension type is "repeat", the same > > opcode is sent twice. When it is "invert", the second byte is the > > inverse of the opcode. When it is "hex" an additional opcode byte based > > is sent with the command whose value can be anything. > > > > Signed-off-by: Pratyush Yadav > > --- > > drivers/spi/spi-mem.c | 23 +++++++++++++++++++++++ > > include/linux/spi/spi-mem.h | 24 ++++++++++++++++++++++++ > > 2 files changed, 47 insertions(+) > > > > diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c > > index cb13e0878b95..3838ddc9aeec 100644 > > --- a/drivers/spi/spi-mem.c > > +++ b/drivers/spi/spi-mem.c > > @@ -462,6 +462,29 @@ int spi_mem_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op) > > } > > EXPORT_SYMBOL_GPL(spi_mem_adjust_op_size); > > > > +int spi_mem_get_cmd_ext(const struct spi_mem_op *op, u8 *ext) > > +{ > > + switch (op->cmd.ext_type) { > > + case SPI_MEM_EXT_INVERT: > > + *ext = ~op->cmd.opcode; > > + break; > > + > > + case SPI_MEM_EXT_REPEAT: > > + *ext = op->cmd.opcode; > > + break; > > + > > + case SPI_MEM_EXT_HEX: > > + *ext = op->cmd.ext; > > + break; > > + > > + default: > > + return -EINVAL; > > + } > > + > > + return 0; > > +} > > +EXPORT_SYMBOL_GPL(spi_mem_get_cmd_ext); > > + > > static ssize_t spi_mem_no_dirmap_read(struct spi_mem_dirmap_desc *desc, > > u64 offs, size_t len, void *buf) > > { > > diff --git a/include/linux/spi/spi-mem.h b/include/linux/spi/spi-mem.h > > index 4669082b4e3b..06ccab17e4d0 100644 > > --- a/include/linux/spi/spi-mem.h > > +++ b/include/linux/spi/spi-mem.h > > @@ -67,11 +67,31 @@ enum spi_mem_data_dir { > > SPI_MEM_DATA_OUT, > > }; > > > > +/** > > + * enum spi_mem_cmd_ext - describes the command opcode extension in DTR mode > > + * @SPI_MEM_EXT_NONE: no extension. This is the default, and is used in Legacy > > + * SPI mode > > + * @SPI_MEM_EXT_REPEAT: the extension is same as the opcode > > + * @SPI_MEM_EXT_INVERT: the extension is the bitwise inverse of the opcode > > + * @SPI_MEM_EXT_HEX: the extension is any hex value. The command and opcode > > + * combine to form a 16-bit opcode. > > + */ > > +enum spi_mem_cmd_ext { > > + SPI_MEM_EXT_NONE = 0, > > + SPI_MEM_EXT_REPEAT, > > + SPI_MEM_EXT_INVERT, > > + SPI_MEM_EXT_HEX, > > +}; > > + > > /** > > * struct spi_mem_op - describes a SPI memory operation > > * @cmd.buswidth: number of IO lines used to transmit the command > > * @cmd.opcode: operation opcode > > * @cmd.is_dtr: whether the command opcode should be sent in DTR mode or not > > + * @cmd.ext_type: type of the command opcode extension in DTR mode > > + * @cmd.ext: value of the command opcode extension in DTR mode. It is > > + * only set when 'ext_type' is 'SPI_MEM_EXT_HEX'. In all other > > + * cases, the extension can be directly derived from the opcode. > > * @addr.nbytes: number of address bytes to send. Can be zero if the operation > > * does not need to send an address > > * @addr.buswidth: number of IO lines used to transmit the address cycles > > @@ -97,6 +117,8 @@ struct spi_mem_op { > > u8 buswidth; > > u8 opcode; > > bool is_dtr; > > + enum spi_mem_cmd_ext ext_type; > > + u8 ext; > > Could we instead make opcode an u16 (or u8[2]) and pass the number of > bytes, as done for the other addr? Mode can be extracted from the > opcode/nbytes values if really needed, and the caller would be > responsible for filling those fields properly (which shouldn't be too > hard) Ok. Will do. > > } cmd; > > > > struct { > > @@ -361,6 +383,8 @@ int spi_mem_driver_register_with_owner(struct spi_mem_driver *drv, > > > > void spi_mem_driver_unregister(struct spi_mem_driver *drv); > > > > +int spi_mem_get_cmd_ext(const struct spi_mem_op *op, u8 *ext); > > + > > #define spi_mem_driver_register(__drv) \ > > spi_mem_driver_register_with_owner(__drv, THIS_MODULE) > > > -- Regards, Pratyush Yadav Texas Instruments India ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/