[PATCH v3] tty: samsung_tty: 32-bit access for TX/RX hold registers

From: Hyunki Koo
Date: Fri Apr 03 2020 - 06:20:59 EST


Support 32-bit access for the TX/RX hold registers UTXH and URXH.

This is required for some newer SoCs.

Signed-off-by: Hyunki Koo <hyunki00.koo@xxxxxxxxxxx>
---
v3: change rd_regl to rd_reg in line 954 for backward compatibility.
---

drivers/tty/serial/samsung_tty.c | 76 +++++++++++++++++++++++++++++++++-------
1 file changed, 64 insertions(+), 12 deletions(-)

diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
index 73f951d65b93..a674a80163ed 100644
--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c
@@ -154,12 +154,47 @@ struct s3c24xx_uart_port {
#define portaddrl(port, reg) \
((unsigned long *)(unsigned long)((port)->membase + (reg)))

-#define rd_regb(port, reg) (readb_relaxed(portaddr(port, reg)))
+static unsigned int rd_reg(struct uart_port *port, int reg)
+{
+ switch (port->iotype) {
+ case UPIO_MEM:
+ return readb_relaxed(portaddr(port, reg));
+ case UPIO_MEM32:
+ return readl_relaxed(portaddr(port, reg));
+ default:
+ return 0;
+ }
+ return 0;
+}
+
#define rd_regl(port, reg) (readl_relaxed(portaddr(port, reg)))

-#define wr_regb(port, reg, val) writeb_relaxed(val, portaddr(port, reg))
+static void wr_reg(struct uart_port *port, int reg, int val)
+{
+ switch (port->iotype) {
+ case UPIO_MEM:
+ writeb_relaxed(val, portaddr(port, reg));
+ break;
+ case UPIO_MEM32:
+ writel_relaxed(val, portaddr(port, reg));
+ break;
+ }
+}
+
#define wr_regl(port, reg, val) writel_relaxed(val, portaddr(port, reg))

+static void write_buf(struct uart_port *port, int reg, int val)
+{
+ switch (port->iotype) {
+ case UPIO_MEM:
+ writeb(val, portaddr(port, reg));
+ break;
+ case UPIO_MEM32:
+ writel(val, portaddr(port, reg));
+ break;
+ }
+}
+
/* Byte-order aware bit setting/clearing functions. */

static inline void s3c24xx_set_bit(struct uart_port *port, int idx,
@@ -714,7 +749,7 @@ static void s3c24xx_serial_rx_drain_fifo(struct s3c24xx_uart_port *ourport)
fifocnt--;

uerstat = rd_regl(port, S3C2410_UERSTAT);
- ch = rd_regb(port, S3C2410_URXH);
+ ch = rd_reg(port, S3C2410_URXH);

if (port->flags & UPF_CONS_FLOW) {
int txe = s3c24xx_serial_txempty_nofifo(port);
@@ -826,7 +861,7 @@ static irqreturn_t s3c24xx_serial_tx_chars(int irq, void *id)
}

if (port->x_char) {
- wr_regb(port, S3C2410_UTXH, port->x_char);
+ wr_reg(port, S3C2410_UTXH, port->x_char);
port->icount.tx++;
port->x_char = 0;
goto out;
@@ -852,7 +887,7 @@ static irqreturn_t s3c24xx_serial_tx_chars(int irq, void *id)
if (rd_regl(port, S3C2410_UFSTAT) & ourport->info->tx_fifofull)
break;

- wr_regb(port, S3C2410_UTXH, xmit->buf[xmit->tail]);
+ wr_reg(port, S3C2410_UTXH, xmit->buf[xmit->tail]);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
port->icount.tx++;
count--;
@@ -916,7 +951,7 @@ static unsigned int s3c24xx_serial_tx_empty(struct uart_port *port)
/* no modem control lines */
static unsigned int s3c24xx_serial_get_mctrl(struct uart_port *port)
{
- unsigned int umstat = rd_regb(port, S3C2410_UMSTAT);
+ unsigned int umstat = rd_reg(port, S3C2410_UMSTAT);

if (umstat & S3C2410_UMSTAT_CTS)
return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
@@ -1974,7 +2009,7 @@ static int s3c24xx_serial_probe(struct platform_device *pdev)
struct device_node *np = pdev->dev.of_node;
struct s3c24xx_uart_port *ourport;
int index = probe_index;
- int ret;
+ int ret, prop = 0;

if (np) {
ret = of_alias_get_id(np, "serial");
@@ -2000,10 +2035,27 @@ static int s3c24xx_serial_probe(struct platform_device *pdev)
dev_get_platdata(&pdev->dev) :
ourport->drv_data->def_cfg;

- if (np)
+ if (np) {
of_property_read_u32(np,
"samsung,uart-fifosize", &ourport->port.fifosize);

+ if (of_property_read_u32(np, "reg-io-width", &prop) == 0) {
+ switch (prop) {
+ case 1:
+ ourport->port.iotype = UPIO_MEM;
+ break;
+ case 4:
+ ourport->port.iotype = UPIO_MEM32;
+ break;
+ default:
+ dev_warn(&pdev->dev, "unsupported reg-io-width (%d)\n",
+ prop);
+ ret = -EINVAL;
+ break;
+ }
+ }
+ }
+
if (ourport->drv_data->fifosize[index])
ourport->port.fifosize = ourport->drv_data->fifosize[index];
else if (ourport->info->fifosize)
@@ -2185,7 +2237,7 @@ static int s3c24xx_serial_get_poll_char(struct uart_port *port)
if (s3c24xx_serial_rx_fifocnt(ourport, ufstat) == 0)
return NO_POLL_CHAR;

- return rd_regb(port, S3C2410_URXH);
+ return rd_reg(port, S3C2410_URXH);
}

static void s3c24xx_serial_put_poll_char(struct uart_port *port,
@@ -2200,7 +2252,7 @@ static void s3c24xx_serial_put_poll_char(struct uart_port *port,

while (!s3c24xx_serial_console_txrdy(port, ufcon))
cpu_relax();
- wr_regb(port, S3C2410_UTXH, c);
+ wr_reg(port, S3C2410_UTXH, c);
}

#endif /* CONFIG_CONSOLE_POLL */
@@ -2212,7 +2264,7 @@ s3c24xx_serial_console_putchar(struct uart_port *port, int ch)

while (!s3c24xx_serial_console_txrdy(port, ufcon))
cpu_relax();
- wr_regb(port, S3C2410_UTXH, ch);
+ wr_reg(port, S3C2410_UTXH, ch);
}

static void
@@ -2612,7 +2664,7 @@ static void samsung_early_putc(struct uart_port *port, int c)
else
samsung_early_busyuart(port);

- writeb(c, port->membase + S3C2410_UTXH);
+ write_buf(port, S3C2410_UTXH, c);
}

static void samsung_early_write(struct console *con, const char *s,
--
2.15.0.rc1