This patch adds back support for half-duplex controllers, which was removed in
the last patch.
Reviewed-by: Dan Murphy <dmurphy@ti.com>
Tested-by: Sean Nyekjaer <sean@geanix.com>
Link: https://lore.kernel.org/r/20201215231746.1132907-17-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch reworks the SPI access and fixes several probems:
- tcan4x5x_regmap_gather_write(), tcan4x5x_regmap_read():
Do not place variable "addr" on stack and use it as buffer for SPI
transfer. Buffers for SPI transfers must be allocated from DMA save
memory.
- tcan4x5x_regmap_gather_write(), tcan4x5x_regmap_read():
Halfe number of SPI transfers by using a single buffer + memcpy().
This improves the performance, especially on SPI controllers, which
use interrupt based transfers.
- Use "8" bits per word, not "32". This makes it possible to use this
driver on SoCs like the Raspberry Pi, which SPI host controller
drivers only support 8 bits per word.
Note: this breaks half duplex only controllers. Support for them will be
re-added in the next patch.
Reviewed-by: Dan Murphy <dmurphy@ti.com>
Tested-by: Sean Nyekjaer <sean@geanix.com>
Link: https://lore.kernel.org/r/20201215231746.1132907-16-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The memory space of the chip is not fully populated, so add a regmap range
table to document this.
Reviewed-by: Dan Murphy <dmurphy@ti.com>
Tested-by: Sean Nyekjaer <sean@geanix.com>
Link: https://lore.kernel.org/r/20201215231746.1132907-15-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The tcan4x5x chip support bulk read/write, but as the length field is only 8
bits wide, the maximum is 256. A length of 0 is treated as 256.
Reviewed-by: Dan Murphy <dmurphy@ti.com>
Tested-by: Sean Nyekjaer <sean@geanix.com>
Link: https://lore.kernel.org/r/20201215231746.1132907-14-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch sets the regmap stide to 4, as the chip only supports access on 32
bit alligned access.
Reviewed-by: Dan Murphy <dmurphy@ti.com>
Tested-by: Sean Nyekjaer <sean@geanix.com>
Link: https://lore.kernel.org/r/20201215231746.1132907-13-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch replaces the context pointer of the regmap callback functions by a
pointer to the spi_device. This saves one level of indirection in the
callbacks.
Reviewed-by: Dan Murphy <dmurphy@ti.com>
Tested-by: Sean Nyekjaer <sean@geanix.com>
Link: https://lore.kernel.org/r/20201215231746.1132907-11-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch simplifies the tcan4x5x_regmap_write(0 function by removing not
needed casts and replaces hardcoded "4" by appropriate sizeof()s.
Reviewed-by: Dan Murphy <dmurphy@ti.com>
Tested-by: Sean Nyekjaer <sean@geanix.com>
Link: https://lore.kernel.org/r/20201215231746.1132907-10-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch renames the regmap_spi_gather_write() function to
tcan4x5x_regmap_gather_write(). Now it has a "tcan4x5x_" prefix as all other
functions in this driver.
Reviewed-by: Dan Murphy <dmurphy@ti.com>
Tested-by: Sean Nyekjaer <sean@geanix.com>
Link: https://lore.kernel.org/r/20201215231746.1132907-9-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The driver doesn't use regmap async support, so remove the stubs.
Reviewed-by: Dan Murphy <dmurphy@ti.com>
Tested-by: Sean Nyekjaer <sean@geanix.com>
Link: https://lore.kernel.org/r/20201215231746.1132907-8-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
With C99 initializers, all non mentioned members are initialzied to 0, so
remove not needed initialization of read_flag_mask.
Reviewed-by: Dan Murphy <dmurphy@ti.com>
Tested-by: Sean Nyekjaer <sean@geanix.com>
Link: https://lore.kernel.org/r/20201215231746.1132907-7-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch marks the struct regmap_bus tcan4x5x_bus as constant.
Reviewed-by: Dan Murphy <dmurphy@ti.com>
Tested-by: Sean Nyekjaer <sean@geanix.com>
Link: https://lore.kernel.org/r/20201215231746.1132907-6-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
