RE: [PATCH v2] tty: samsung_tty: 32-bit access for TX/RX hold registers
From: Hyunki Koo
Date: Fri Apr 03 2020 - 03:30:48 EST
On Thu, Apr 02, 2020 at 10:59:29PM +0900, Krzysztof Kozlowski
> On Thu, Apr 02, 2020 at 08:04:29PM +0900, Hyunki Koo wrote:
> > 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>
> > ---
> > drivers/tty/serial/samsung_tty.c | 78
> > +++++++++++++++++++++++++++++++++-------
> > 1 file changed, 66 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/tty/serial/samsung_tty.c
> > b/drivers/tty/serial/samsung_tty.c
> > index 73f951d65b93..826d8c5846a6 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
> +2035,29 @@ 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;
> > + }
> > + } else {
> > + ourport->port.iotype = UPIO_MEM;
> > + }
> > + }
>
> I think this still breaks all non-DT platforms (e.g. s3c).
>
> Best regards,
> Krzysztof
Thank you for your comment.
I hope ourport->port.iotype is initialized by below table for non-DT platforms
1662 static struct s3c24xx_uart_port
1663 s3c24xx_serial_ports[CONFIG_SERIAL_SAMSUNG_UARTS] = {
1664 [0] = {
1665 .port = {
1666 .lock = __PORT_LOCK_UNLOCKED(0),
1667 .iotype = UPIO_MEM,
1668 .uartclk = 0,
1669 .fifosize = 16,
1670 .ops = &s3c24xx_serial_ops,
1671 .flags = UPF_BOOT_AUTOCONF,
1672 .line = 0,
1673 }
1674 },
1675 [1] = {
1676 .port = {
1677 .lock = __PORT_LOCK_UNLOCKED(1),
1678 .iotype = UPIO_MEM,
1679 .uartclk = 0,
1680 .fifosize = 16,
1681 .ops = &s3c24xx_serial_ops,
1682 .flags = UPF_BOOT_AUTOCONF,
1683 .line = 1,
1684 }
1685 },