[PATCH 10/12] tty: amba-pl011: add support for 32-bit register access
Russell King
rmk+kernel at arm.linux.org.uk
Mon Nov 16 09:40:52 PST 2015
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 at arm.linux.org.uk>
---
drivers/tty/serial/amba-pl011.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index afa0de7d481f..3470a1e67bbc 100644
--- 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);
--
2.1.0
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