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From: Tudor Ambarus <tudor.ambarus@linaro.org>
To: krzysztof.kozlowski@linaro.org,
	alim.akhtar@samsung.com,
	gregkh@linuxfoundation.org,
	jirislaby@kernel.org
Cc: linux-arm-kernel@lists.infradead.org,
	linux-samsung-soc@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	linux-serial@vger.kernel.org,
	andre.draszik@linaro.org,
	peter.griffin@linaro.org,
	kernel-team@android.com,
	willmcvicker@google.com,
	Tudor Ambarus <tudor.ambarus@linaro.org>
Subject: [PATCH 01/18] tty: serial: samsung: prepare for different IO types
Date: Wed, 10 Jan 2024 10:20:45 +0000
Message-ID: <20240110102102.61587-2-tudor.ambarus@linaro.org>
In-Reply-To: <20240110102102.61587-1-tudor.ambarus@linaro.org>
References: <20240110102102.61587-1-tudor.ambarus@linaro.org>
Precedence: bulk
MIME-Version: 1.0
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GS101's Connectivity Peripheral blocks (peric0/1 blocks) which
include the I3C and USI (I2C, SPI, UART) only allow 32-bit
register accesses. If using 8-bit register accesses, a SError
Interrupt is raised causing the system unusable.

Instead of specifying the reg-io-width = 4 everywhere, for each node,
the requirement should be deduced from the compatible.

Prepare the samsung tty driver to allow IO types different than
UPIO_MEM. ``struct uart_port::iotype`` is an unsigned char where all
its 8 bits are exposed to uapi. We can't make NULL checks on it to
verify if it's set, thus always set it from the driver's data.
Use u8 for the ``iotype`` member of ``struct s3c24xx_uart_info`` to
emphasize that the iotype is an 8 bit mask.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
---
 drivers/tty/serial/samsung_tty.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
index 71d17d804fda..b8fe9df20202 100644
--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c
@@ -84,6 +84,7 @@ struct s3c24xx_uart_info {
 	unsigned long		clksel_mask;
 	unsigned long		clksel_shift;
 	unsigned long		ucon_mask;
+	u8			iotype;
 
 	/* uart port features */
 
@@ -1742,7 +1743,6 @@ static void s3c24xx_serial_init_port_default(int index) {
 
 	spin_lock_init(&port->lock);
 
-	port->iotype = UPIO_MEM;
 	port->uartclk = 0;
 	port->fifosize = 16;
 	port->flags = UPF_BOOT_AUTOCONF;
@@ -1989,6 +1989,8 @@ static int s3c24xx_serial_probe(struct platform_device *pdev)
 		break;
 	}
 
+	ourport->port.iotype = ourport->info->iotype;
+
 	if (np) {
 		of_property_read_u32(np,
 			"samsung,uart-fifosize", &ourport->port.fifosize);
@@ -2399,6 +2401,7 @@ static const struct s3c24xx_serial_drv_data s3c6400_serial_drv_data = {
 		.name		= "Samsung S3C6400 UART",
 		.type		= TYPE_S3C6400,
 		.port_type	= PORT_S3C6400,
+		.iotype		= UPIO_MEM,
 		.fifosize	= 64,
 		.has_divslot	= 1,
 		.rx_fifomask	= S3C2440_UFSTAT_RXMASK,
@@ -2428,6 +2431,7 @@ static const struct s3c24xx_serial_drv_data s5pv210_serial_drv_data = {
 		.name		= "Samsung S5PV210 UART",
 		.type		= TYPE_S3C6400,
 		.port_type	= PORT_S3C6400,
+		.iotype		= UPIO_MEM,
 		.has_divslot	= 1,
 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,
 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,
@@ -2457,6 +2461,7 @@ static const struct s3c24xx_serial_drv_data s5pv210_serial_drv_data = {
 		.name		= "Samsung Exynos UART",	\
 		.type		= TYPE_S3C6400,			\
 		.port_type	= PORT_S3C6400,			\
+		.iotype		= UPIO_MEM,			\
 		.has_divslot	= 1,				\
 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,	\
 		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,	\
@@ -2517,6 +2522,7 @@ static const struct s3c24xx_serial_drv_data s5l_serial_drv_data = {
 		.name		= "Apple S5L UART",
 		.type		= TYPE_APPLE_S5L,
 		.port_type	= PORT_8250,
+		.iotype		= UPIO_MEM,
 		.fifosize	= 16,
 		.rx_fifomask	= S3C2410_UFSTAT_RXMASK,
 		.rx_fifoshift	= S3C2410_UFSTAT_RXSHIFT,
@@ -2546,6 +2552,7 @@ static const struct s3c24xx_serial_drv_data artpec8_serial_drv_data = {
 		.name		= "Axis ARTPEC-8 UART",
 		.type		= TYPE_S3C6400,
 		.port_type	= PORT_S3C6400,
+		.iotype		= UPIO_MEM,
 		.fifosize	= 64,
 		.has_divslot	= 1,
 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,
-- 
2.43.0.472.g3155946c3a-goog