From 78506f223a7bb7d47b1772592932921689adc6d8 Mon Sep 17 00:00:00 2001 From: Jongsung Kim Date: Mon, 15 Apr 2013 14:45:25 +0900 Subject: 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 Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/amba-pl011.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) (limited to 'drivers/tty/serial/amba-pl011.c') diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index 6cf861e..b2e9e17 100644 --- 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; -- cgit v1.1