tty: amba-pl011: use iotype instead of access_32b to track 32-bit I/O

Instead of defining a new field in the uart_amba_port structure, use the
existing iotype field of the uart_port structure, which is intended for
this purpose.  If we need to use 32-bit register access, we set iotype
to UPIO_MEM32, otherwise we set it to UPIO_MEM.

For early console, specify the "mmio32" option on the kernel command-line.
Example:

        earlycon=pl011,mmio32,0x3ced1000

Signed-off-by: Timur Tabi <timur@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 13 insertions, 8 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 054e11d33b6b..654c547b9fc9 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1003,10 +1003,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                         unspecified, the h/w is not initialized.
 
                 pl011,<addr>
+                pl011,mmio32,<addr>
                         Start an early, polled-mode console on a pl011 serial
                         port at the specified address. The pl011 serial port
                         must already be setup and configured. Options are not
-                        yet supported.
+                        yet supported.  If 'mmio32' is specified, then only
+                        the driver will use only 32-bit accessors to read/write
+                        the device registers.
 
                 msm_serial,<addr>
                         Start an early, polled-mode console on an msm serial
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index a7d7ab05dc64..c0da0ccbbcf5 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -238,7 +238,6 @@ struct uart_amba_port {
         unsigned int            fifosize;       /* vendor-specific */
         unsigned int            old_cr;         /* state during shutdown */
         bool                    autorts;
-        bool                    access_32b;
         unsigned int            fixed_baud;     /* vendor-set fixed baud rate */
         char                    type[12];
 #ifdef CONFIG_DMA_ENGINE
@@ -262,7 +261,8 @@ static unsigned int pl011_read(const struct uart_amba_port *uap,
 {
         void __iomem *addr = uap->port.membase + pl011_reg_to_offset(uap, reg);
 
-        return uap->access_32b ? readl_relaxed(addr) : readw_relaxed(addr);
+        return (uap->port.iotype == UPIO_MEM32) ?
+                readl_relaxed(addr) : readw_relaxed(addr);
 }
 
 static void pl011_write(unsigned int val, const struct uart_amba_port *uap,
@@ -270,7 +270,7 @@ static void pl011_write(unsigned int val, const struct uart_amba_port *uap,
 {
         void __iomem *addr = uap->port.membase + pl011_reg_to_offset(uap, reg);
 
-        if (uap->access_32b)
+        if (uap->port.iotype == UPIO_MEM32)
                 writel_relaxed(val, addr);
         else
                 writew_relaxed(val, addr);
@@ -2303,7 +2303,10 @@ static void pl011_putc(struct uart_port *port, int c)
 {
         while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF)
                 ;
-        writeb(c, port->membase + UART01x_DR);
+        if (port->iotype == UPIO_MEM32)
+                writel(c, port->membase + UART01x_DR);
+        else
+                writeb(c, port->membase + UART01x_DR);
         while (readl(port->membase + UART01x_FR) & UART01x_FR_BUSY)
                 ;
 }
@@ -2416,7 +2419,6 @@ static int pl011_setup_port(struct device *dev, struct uart_amba_port *uap,
         uap->port.dev = dev;
         uap->port.mapbase = mmiobase->start;
         uap->port.membase = base;
-        uap->port.iotype = UPIO_MEM;
         uap->port.fifosize = uap->fifosize;
         uap->port.flags = UPF_BOOT_AUTOCONF;
         uap->port.line = index;
@@ -2470,9 +2472,9 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
                 return PTR_ERR(uap->clk);
 
         uap->reg_offset = vendor->reg_offset;
-        uap->access_32b = vendor->access_32b;
         uap->vendor = vendor;
         uap->fifosize = vendor->get_fifosize(dev);
+        uap->port.iotype = vendor->access_32b ? UPIO_MEM32 : UPIO_MEM;
         uap->port.irq = dev->irq[0];
         uap->port.ops = &amba_pl011_pops;
 
@@ -2551,9 +2553,9 @@ static int sbsa_uart_probe(struct platform_device *pdev)
                 return -ENOMEM;
 
         uap->reg_offset = vendor_sbsa.reg_offset;
-        uap->access_32b = vendor_sbsa.access_32b;
         uap->vendor     = &vendor_sbsa;
         uap->fifosize   = 32;
+        uap->port.iotype = vendor_sbsa.access_32b ? UPIO_MEM32 : UPIO_MEM;
         uap->port.irq   = platform_get_irq(pdev, 0);
         uap->port.ops   = &sbsa_uart_pops;
         uap->fixed_baud = baudrate;