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@xxxxxxx>
---
drivers/tty/serial/amba-pl011.c | 20 ++++++++++++++++----
1 files changed, 16 insertions(+), 4 deletions(-)
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 3ea5408..22af0c8 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -72,32 +72,44 @@
/* 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];
@@ -2010,7 +2022,7 @@ 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;
--
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