ARM: PL011: add support for extended FIFO-size of PL011-r1p5

The latest r1p5-revision of the ARM PL011 UART has 32-byte FIFOs,
while all earlier ones have 16-byte FIFOs. This patch suggests
a way to set the FIFO-size correctly & flexibly by using a member
function named get_fifosize, rather than using the fifosize member
variable. The function takes the UARTPeriphID, and returns the
correct FIFO size.

Signed-off-by: Jongsung Kim <neidhard.kim@lge.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 6cf861efb2afaf3ef5639cb2077ff40092f7529d..b2e9e177a354dc16f1e6654a68c19855f9fdba0e 100644 (file)
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -73,32 +73,44 @@
 /* There is by now at least one vendor with differing details, so handle it */
 struct vendor_data {
        unsigned int            ifls;
-       unsigned int            fifosize;
        unsigned int            lcrh_tx;
        unsigned int            lcrh_rx;
        bool                    oversampling;
        bool                    dma_threshold;
        bool                    cts_event_workaround;
+
+       unsigned int (*get_fifosize)(unsigned int periphid);
 };
 
+static unsigned int get_fifosize_arm(unsigned int periphid)
+{
+       unsigned int rev = (periphid >> 20) & 0xf;
+       return rev < 3 ? 16 : 32;
+}
+
 static struct vendor_data vendor_arm = {
        .ifls                   = UART011_IFLS_RX4_8|UART011_IFLS_TX4_8,
-       .fifosize               = 16,
        .lcrh_tx                = UART011_LCRH,
        .lcrh_rx                = UART011_LCRH,
        .oversampling           = false,
        .dma_threshold          = false,
        .cts_event_workaround   = false,
+       .get_fifosize           = get_fifosize_arm,
 };
 
+static unsigned int get_fifosize_st(unsigned int periphid)
+{
+       return 64;
+}
+
 static struct vendor_data vendor_st = {
        .ifls                   = UART011_IFLS_RX_HALF|UART011_IFLS_TX_HALF,
-       .fifosize               = 64,
        .lcrh_tx                = ST_UART011_LCRH_TX,
        .lcrh_rx                = ST_UART011_LCRH_RX,
        .oversampling           = true,
        .dma_threshold          = true,
        .cts_event_workaround   = true,
+       .get_fifosize           = get_fifosize_st,
 };
 
 static struct uart_amba_port *amba_ports[UART_NR];
@@ -2133,7 +2145,7 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
        uap->lcrh_rx = vendor->lcrh_rx;
        uap->lcrh_tx = vendor->lcrh_tx;
        uap->old_cr = 0;
-       uap->fifosize = vendor->fifosize;
+       uap->fifosize = vendor->get_fifosize(dev->periphid);
        uap->port.dev = &dev->dev;
        uap->port.mapbase = dev->res.start;
        uap->port.membase = base;