tty: amba-pl011: add support for 32-bit register access

Add support for 32-bit register accesses to the AMBA PL011 UART.  This
is needed for ZTE UARTs, which require 32-bit accesses as opposed to
the more normal 16-bit accesses.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index e0f9e3e739d09a49fe1f2a1a451f42632f6b14b1..c8165b61dbf845b8afcc6e74e7636540a079d8bb 100644 (file)
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -93,6 +93,7 @@ static u16 pl011_std_offsets[REG_ARRAY_SIZE] = {
 struct vendor_data {
        const u16               *reg_offset;
        unsigned int            ifls;
+       bool                    access_32b;
        bool                    oversampling;
        bool                    dma_threshold;
        bool                    cts_event_workaround;
@@ -214,6 +215,7 @@ 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
@@ -235,13 +237,20 @@ static unsigned int pl011_reg_to_offset(const struct uart_amba_port *uap,
 static unsigned int pl011_read(const struct uart_amba_port *uap,
        unsigned int reg)
 {
-       return readw(uap->port.membase + pl011_reg_to_offset(uap, reg));
+       void __iomem *addr = uap->port.membase + pl011_reg_to_offset(uap, reg);
+
+       return uap->access_32b ? readl(addr) : readw(addr);
 }
 
 static void pl011_write(unsigned int val, const struct uart_amba_port *uap,
        unsigned int reg)
 {
-       writew(val, uap->port.membase + pl011_reg_to_offset(uap, reg));
+       void __iomem *addr = uap->port.membase + pl011_reg_to_offset(uap, reg);
+
+       if (uap->access_32b)
+               writel(val, addr);
+       else
+               writew(val, addr);
 }
 
 /*
@@ -2438,6 +2447,7 @@ 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.irq = dev->irq[0];
@@ -2518,6 +2528,7 @@ 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.irq   = platform_get_irq(pdev, 0);