Unverified Commit b7bafb9f authored by Tudor Ambarus's avatar Tudor Ambarus Committed by Mark Brown
Browse files

spi: s3c64xx: add s3c64xx_iowrite{8,16}_32_rep accessors 



Allow SoCs that require 32 bits register accesses to write data in
chunks of 8 or 16 bits. One SoC that requires 32 bit register accesses
is the google gs101. The operation is rare, thus open code it in the
driver rather than making it generic (through asm-generic/io.h).

Signed-off-by: default avatarTudor Ambarus <tudor.ambarus@linaro.org>
Link: https://lore.kernel.org/r/20240207111516.2563218-4-tudor.ambarus@linaro.org


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 80d3204a

drivers/spi/spi-s3c64xx.c

+34 −2
Original line number Diff line number Diff line
@@ -142,6 +142,7 @@ struct s3c64xx_spi_dma_data { 
 *	prescaler unit.

 * @clk_ioclk: True if clock is present on this device

 * @has_loopback: True if loopback mode can be supported

 * @use_32bit_io: True if the SoC allows only 32-bit register accesses.

 *

 * The Samsung s3c64xx SPI controller are used on various Samsung SoC's but

 * differ in some aspects such as the size of the fifo and spi bus clock
@@ -158,6 +159,7 @@ struct s3c64xx_spi_port_config { 
	bool	clk_from_cmu;

	bool	clk_ioclk;

	bool	has_loopback;

	bool	use_32bit_io;

};



/**
@@ -414,6 +416,30 @@ static bool s3c64xx_spi_can_dma(struct spi_controller *host, 


}



static void s3c64xx_iowrite8_32_rep(volatile void __iomem *addr,

				    const void *buffer, unsigned int count)

{

	if (count) {

		const u8 *buf = buffer;



		do {

			__raw_writel(*buf++, addr);

		} while (--count);

	}

}



static void s3c64xx_iowrite16_32_rep(volatile void __iomem *addr,

				     const void *buffer, unsigned int count)

{

	if (count) {

		const u16 *buf = buffer;



		do {

			__raw_writel(*buf++, addr);

		} while (--count);

	}

}



static void s3c64xx_iowrite_rep(const struct s3c64xx_spi_driver_data *sdd,

				struct spi_transfer *xfer)

{
@@ -426,9 +452,15 @@ static void s3c64xx_iowrite_rep(const struct s3c64xx_spi_driver_data *sdd, 
		iowrite32_rep(addr, buf, len / 4);

		break;

	case 16:

		if (sdd->port_conf->use_32bit_io)

			s3c64xx_iowrite16_32_rep(addr, buf, len / 2);

		else

			iowrite16_rep(addr, buf, len / 2);

		break;

	default:

		if (sdd->port_conf->use_32bit_io)

			s3c64xx_iowrite8_32_rep(addr, buf, len);

		else

			iowrite8_rep(addr, buf, len);

		break;

	}