altera_uart: Add support for different address strides

Some controllers implement registers with a stride, to support
those we must implement the proper IO accessors.

Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
Acked-by: Tobias Klauser <tklauser@distanz.ch>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 38 insertions, 21 deletions

diff --git a/drivers/serial/altera_uart.c b/drivers/serial/altera_uart.c
index 1dfeffae5231..f1985aaf2cbc 100644
--- a/drivers/serial/altera_uart.c
+++ b/drivers/serial/altera_uart.c
@@ -82,9 +82,23 @@ struct altera_uart {
         unsigned short imr;     /* Local IMR mirror */
 };
 
+static u32 altera_uart_readl(struct uart_port *port, int reg)
+{
+        struct altera_uart_platform_uart *platp = port->private_data;
+
+        return readl(port->membase + (reg << platp->bus_shift));
+}
+
+static void altera_uart_writel(struct uart_port *port, u32 dat, int reg)
+{
+        struct altera_uart_platform_uart *platp = port->private_data;
+
+        writel(dat, port->membase + (reg << platp->bus_shift));
+}
+
 static unsigned int altera_uart_tx_empty(struct uart_port *port)
 {
-        return (readl(port->membase + ALTERA_UART_STATUS_REG) &
+        return (altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
                 ALTERA_UART_STATUS_TMT_MSK) ? TIOCSER_TEMT : 0;
 }
 
@@ -93,8 +107,7 @@ static unsigned int altera_uart_get_mctrl(struct uart_port *port)
         struct altera_uart *pp = container_of(port, struct altera_uart, port);
         unsigned int sigs;
 
-        sigs =
-            (readl(port->membase + ALTERA_UART_STATUS_REG) &
+        sigs = (altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
              ALTERA_UART_STATUS_CTS_MSK) ? TIOCM_CTS : 0;
         sigs |= (pp->sigs & TIOCM_RTS);
 
@@ -110,7 +123,7 @@ static void altera_uart_set_mctrl(struct uart_port *port, unsigned int sigs)
                 pp->imr |= ALTERA_UART_CONTROL_RTS_MSK;
         else
                 pp->imr &= ~ALTERA_UART_CONTROL_RTS_MSK;
-        writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
+        altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
 }
 
 static void altera_uart_start_tx(struct uart_port *port)
@@ -118,7 +131,7 @@ static void altera_uart_start_tx(struct uart_port *port)
         struct altera_uart *pp = container_of(port, struct altera_uart, port);
 
         pp->imr |= ALTERA_UART_CONTROL_TRDY_MSK;
-        writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
+        altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
 }
 
 static void altera_uart_stop_tx(struct uart_port *port)
@@ -126,7 +139,7 @@ static void altera_uart_stop_tx(struct uart_port *port)
         struct altera_uart *pp = container_of(port, struct altera_uart, port);
 
         pp->imr &= ~ALTERA_UART_CONTROL_TRDY_MSK;
-        writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
+        altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
 }
 
 static void altera_uart_stop_rx(struct uart_port *port)
@@ -134,7 +147,7 @@ static void altera_uart_stop_rx(struct uart_port *port)
         struct altera_uart *pp = container_of(port, struct altera_uart, port);
 
         pp->imr &= ~ALTERA_UART_CONTROL_RRDY_MSK;
-        writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
+        altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
 }
 
 static void altera_uart_break_ctl(struct uart_port *port, int break_state)
@@ -147,7 +160,7 @@ static void altera_uart_break_ctl(struct uart_port *port, int break_state)
                 pp->imr |= ALTERA_UART_CONTROL_TRBK_MSK;
         else
                 pp->imr &= ~ALTERA_UART_CONTROL_TRBK_MSK;
-        writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
+        altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
         spin_unlock_irqrestore(&port->lock, flags);
 }
 
@@ -171,7 +184,7 @@ static void altera_uart_set_termios(struct uart_port *port,
 
         spin_lock_irqsave(&port->lock, flags);
         uart_update_timeout(port, termios->c_cflag, baud);
-        writel(baudclk, port->membase + ALTERA_UART_DIVISOR_REG);
+        altera_uart_writel(port, baudclk, ALTERA_UART_DIVISOR_REG);
         spin_unlock_irqrestore(&port->lock, flags);
 }
 
@@ -181,14 +194,15 @@ static void altera_uart_rx_chars(struct altera_uart *pp)
         unsigned char ch, flag;
         unsigned short status;
 
-        while ((status = readl(port->membase + ALTERA_UART_STATUS_REG)) &
+        while ((status = altera_uart_readl(port, ALTERA_UART_STATUS_REG)) &
                ALTERA_UART_STATUS_RRDY_MSK) {
-                ch = readl(port->membase + ALTERA_UART_RXDATA_REG);
+                ch = altera_uart_readl(port, ALTERA_UART_RXDATA_REG);
                 flag = TTY_NORMAL;
                 port->icount.rx++;
 
                 if (status & ALTERA_UART_STATUS_E_MSK) {
-                        writel(status, port->membase + ALTERA_UART_STATUS_REG);
+                        altera_uart_writel(port, status,
+                                           ALTERA_UART_STATUS_REG);
 
                         if (status & ALTERA_UART_STATUS_BRK_MSK) {
                                 port->icount.brk++;
@@ -228,18 +242,18 @@ static void altera_uart_tx_chars(struct altera_uart *pp)
 
         if (port->x_char) {
                 /* Send special char - probably flow control */
-                writel(port->x_char, port->membase + ALTERA_UART_TXDATA_REG);
+                altera_uart_writel(port, port->x_char, ALTERA_UART_TXDATA_REG);
                 port->x_char = 0;
                 port->icount.tx++;
                 return;
         }
 
-        while (readl(port->membase + ALTERA_UART_STATUS_REG) &
+        while (altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
                ALTERA_UART_STATUS_TRDY_MSK) {
                 if (xmit->head == xmit->tail)
                         break;
-                writel(xmit->buf[xmit->tail],
-                       port->membase + ALTERA_UART_TXDATA_REG);
+                altera_uart_writel(port, xmit->buf[xmit->tail],
+                       ALTERA_UART_TXDATA_REG);
                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
                 port->icount.tx++;
         }
@@ -249,7 +263,7 @@ static void altera_uart_tx_chars(struct altera_uart *pp)
 
         if (xmit->head == xmit->tail) {
                 pp->imr &= ~ALTERA_UART_CONTROL_TRDY_MSK;
-                writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
+                altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
         }
 }
 
@@ -259,7 +273,7 @@ static irqreturn_t altera_uart_interrupt(int irq, void *data)
         struct altera_uart *pp = container_of(port, struct altera_uart, port);
         unsigned int isr;
 
-        isr = readl(port->membase + ALTERA_UART_STATUS_REG) & pp->imr;
+        isr = altera_uart_readl(port, ALTERA_UART_STATUS_REG) & pp->imr;
 
         spin_lock(&port->lock);
         if (isr & ALTERA_UART_STATUS_RRDY_MSK)
@@ -285,9 +299,9 @@ static void altera_uart_config_port(struct uart_port *port, int flags)
         port->type = PORT_ALTERA_UART;
 
         /* Clear mask, so no surprise interrupts. */
-        writel(0, port->membase + ALTERA_UART_CONTROL_REG);
+        altera_uart_writel(port, 0, ALTERA_UART_CONTROL_REG);
         /* Clear status register */
-        writel(0, port->membase + ALTERA_UART_STATUS_REG);
+        altera_uart_writel(port, 0, ALTERA_UART_STATUS_REG);
 }
 
 static int altera_uart_startup(struct uart_port *port)
@@ -407,6 +421,7 @@ int __init early_altera_uart_setup(struct altera_uart_platform_uart *platp)
                 port->uartclk = platp[i].uartclk;
                 port->flags = ASYNC_BOOT_AUTOCONF;
                 port->ops = &altera_uart_ops;
+                port->private_data = platp;
         }
 
         return 0;
@@ -414,7 +429,7 @@ int __init early_altera_uart_setup(struct altera_uart_platform_uart *platp)
 
 static void altera_uart_console_putc(struct uart_port *port, const char c)
 {
-        while (!(readl(port->membase + ALTERA_UART_STATUS_REG) &
+        while (!(altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
                  ALTERA_UART_STATUS_TRDY_MSK))
                 cpu_relax();
 
@@ -535,6 +550,7 @@ static int __devinit altera_uart_probe(struct platform_device *pdev)
         port->uartclk = platp->uartclk;
         port->ops = &altera_uart_ops;
         port->flags = ASYNC_BOOT_AUTOCONF;
+        port->private_data = platp;
 
         uart_add_one_port(&altera_uart_driver, port);
 
diff --git a/include/linux/altera_uart.h b/include/linux/altera_uart.h
index 8d441064a30d..c022c82db7ca 100644
--- a/include/linux/altera_uart.h
+++ b/include/linux/altera_uart.h
@@ -9,6 +9,7 @@ struct altera_uart_platform_uart {
         unsigned long mapbase;  /* Physical address base */
         unsigned int irq;       /* Interrupt vector */
         unsigned int uartclk;   /* UART clock rate */
+        unsigned int bus_shift; /* Bus shift (address stride) */
 };
 
 #endif /* __ALTUART_H */