diff mbox series

[4/8] tty: serial: samsung: Remove USI initialization

Message ID 20211127223253.19098-5-semen.protsenko@linaro.org (mailing list archive)
State Superseded
Headers show
Series soc: samsung: Add USIv2 driver | expand

Commit Message

Sam Protsenko Nov. 27, 2021, 10:32 p.m. UTC 
USI control is now extracted to dedicated USIv2 driver. Remove USI
related code from serial driver to avoid conflicts and code duplication.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
---
 drivers/tty/serial/samsung_tty.c | 36 ++++----------------------------
 include/linux/serial_s3c.h       |  9 --------
 2 files changed, 4 insertions(+), 41 deletions(-)

Comments

Greg Kroah-Hartman Nov. 28, 2021, 2:28 p.m. UTC | #1 
On Sun, Nov 28, 2021 at 12:32:49AM +0200, Sam Protsenko wrote:
> USI control is now extracted to dedicated USIv2 driver. Remove USI
> related code from serial driver to avoid conflicts and code duplication.

What conflicts?

What duplication?  All you did here was delete code.

confused,

greg k-h
Sam Protsenko Nov. 28, 2021, 4:26 p.m. UTC | #2 
On Sun, 28 Nov 2021 at 16:28, Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Sun, Nov 28, 2021 at 12:32:49AM +0200, Sam Protsenko wrote:
> > USI control is now extracted to dedicated USIv2 driver. Remove USI
> > related code from serial driver to avoid conflicts and code duplication.
>
> What conflicts?
>

There might be possible conflicts when accessing the same USI register
from both serial driver and USIv2 driver. Also there will be conflicts
when trying to access the same I/O address space in those both
drivers.

> What duplication?  All you did here was delete code.
>

It's all explained in [PATCH 0/8], but long story short, I've added
USIv2 driver (in this series) which handles the code that's removed
from serial driver in this patch.

> confused,
>
> greg k-h
Sam Protsenko Nov. 28, 2021, 5:03 p.m. UTC | #3 
On Sun, 28 Nov 2021 at 18:26, Sam Protsenko <semen.protsenko@linaro.org> wrote:
>
> On Sun, 28 Nov 2021 at 16:28, Greg Kroah-Hartman
> <gregkh@linuxfoundation.org> wrote:
> >
> > On Sun, Nov 28, 2021 at 12:32:49AM +0200, Sam Protsenko wrote:
> > > USI control is now extracted to dedicated USIv2 driver. Remove USI
> > > related code from serial driver to avoid conflicts and code duplication.
> >
> > What conflicts?
> >
>
> There might be possible conflicts when accessing the same USI register
> from both serial driver and USIv2 driver. Also there will be conflicts
> when trying to access the same I/O address space in those both
> drivers.
>
> > What duplication?  All you did here was delete code.
> >
>
> It's all explained in [PATCH 0/8], but long story short, I've added
> USIv2 driver (in this series) which handles the code that's removed
> from serial driver in this patch.
>

In other words, this code is now present here: [1]. But of course
USIv2 driver must be applied first, and then this patch (removing the
same code from serial driver). That's why it's in the same series and
it's placed after USIv2 driver ([PATCH 3/8]).

[1] https://patchwork.kernel.org/project/linux-samsung-soc/patch/20211127223253.19098-4-semen.protsenko@linaro.org/

> > confused,
> >
> > greg k-h
diff mbox series

Patch

diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
index ca084c10d0bb..f986a9253dc8 100644
--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c
@@ -65,7 +65,6 @@  enum s3c24xx_port_type {
 struct s3c24xx_uart_info {
 	char			*name;
 	enum s3c24xx_port_type	type;
-	bool			has_usi;
 	unsigned int		port_type;
 	unsigned int		fifosize;
 	unsigned long		rx_fifomask;
@@ -1357,28 +1356,6 @@  static int apple_s5l_serial_startup(struct uart_port *port)
 	return ret;
 }
 
-static void exynos_usi_init(struct uart_port *port)
-{
-	struct s3c24xx_uart_port *ourport = to_ourport(port);
-	struct s3c24xx_uart_info *info = ourport->info;
-	unsigned int val;
-
-	if (!info->has_usi)
-		return;
-
-	/* Clear the software reset of USI block (it's set at startup) */
-	val = rd_regl(port, USI_CON);
-	val &= ~USI_CON_RESET_MASK;
-	wr_regl(port, USI_CON, val);
-	udelay(1);
-
-	/* Continuously provide the clock to USI IP w/o gating (for Rx mode) */
-	val = rd_regl(port, USI_OPTION);
-	val &= ~USI_OPTION_HWACG_MASK;
-	val |= USI_OPTION_HWACG_CLKREQ_ON;
-	wr_regl(port, USI_OPTION, val);
-}
-
 /* power power management control */
 
 static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level,
@@ -1405,8 +1382,6 @@  static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level,
 
 		if (!IS_ERR(ourport->baudclk))
 			clk_prepare_enable(ourport->baudclk);
-
-		exynos_usi_init(port);
 		break;
 	default:
 		dev_err(port->dev, "s3c24xx_serial: unknown pm %d\n", level);
@@ -2130,8 +2105,6 @@  static int s3c24xx_serial_init_port(struct s3c24xx_uart_port *ourport,
 	if (ret)
 		pr_warn("uart: failed to enable baudclk\n");
 
-	exynos_usi_init(port);
-
 	/* Keep all interrupts masked and cleared */
 	switch (ourport->info->type) {
 	case TYPE_S3C6400:
@@ -2780,11 +2753,10 @@  static struct s3c24xx_serial_drv_data s5pv210_serial_drv_data = {
 #endif
 
 #if defined(CONFIG_ARCH_EXYNOS)
-#define EXYNOS_COMMON_SERIAL_DRV_DATA(_has_usi)			\
+#define EXYNOS_COMMON_SERIAL_DRV_DATA()				\
 	.info = &(struct s3c24xx_uart_info) {			\
 		.name		= "Samsung Exynos UART",	\
 		.type		= TYPE_S3C6400,			\
-		.has_usi	= _has_usi,			\
 		.port_type	= PORT_S3C6400,			\
 		.has_divslot	= 1,				\
 		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,	\
@@ -2805,17 +2777,17 @@  static struct s3c24xx_serial_drv_data s5pv210_serial_drv_data = {
 	}							\
 
 static struct s3c24xx_serial_drv_data exynos4210_serial_drv_data = {
-	EXYNOS_COMMON_SERIAL_DRV_DATA(false),
+	EXYNOS_COMMON_SERIAL_DRV_DATA(),
 	.fifosize = { 256, 64, 16, 16 },
 };
 
 static struct s3c24xx_serial_drv_data exynos5433_serial_drv_data = {
-	EXYNOS_COMMON_SERIAL_DRV_DATA(false),
+	EXYNOS_COMMON_SERIAL_DRV_DATA(),
 	.fifosize = { 64, 256, 16, 256 },
 };
 
 static struct s3c24xx_serial_drv_data exynos850_serial_drv_data = {
-	EXYNOS_COMMON_SERIAL_DRV_DATA(true),
+	EXYNOS_COMMON_SERIAL_DRV_DATA(),
 	.fifosize = { 256, 64, 64, 64 },
 };
 
diff --git a/include/linux/serial_s3c.h b/include/linux/serial_s3c.h
index cf0de4a86640..f6c3323fc4c5 100644
--- a/include/linux/serial_s3c.h
+++ b/include/linux/serial_s3c.h
@@ -27,15 +27,6 @@ 
 #define S3C2410_UERSTAT	  (0x14)
 #define S3C2410_UFSTAT	  (0x18)
 #define S3C2410_UMSTAT	  (0x1C)
-#define USI_CON		  (0xC4)
-#define USI_OPTION	  (0xC8)
-
-#define USI_CON_RESET			(1<<0)
-#define USI_CON_RESET_MASK		(1<<0)
-
-#define USI_OPTION_HWACG_CLKREQ_ON	(1<<1)
-#define USI_OPTION_HWACG_CLKSTOP_ON	(1<<2)
-#define USI_OPTION_HWACG_MASK		(3<<1)
 
 #define S3C2410_LCON_CFGMASK	  ((0xF<<3)|(0x3))