For some reason we do not really understand, ZTE hardware designers
choose to define PL011 Flag Register bit positions differently from
standard ones as below.
Bit Standard ZTE
-----------------------------------
CTS 0 1
DSR 1 3
BUSY 3 8
RI 8 0
Let's define these bits into vendor data and get ZTE PL011 supported
properly.
Signed-off-by: Shawn Guo <shawn.guo@xxxxxxxxxx>
---
drivers/tty/serial/amba-pl011.c | 45 ++++++++++++++++++++++++++++++++---------
include/linux/amba/serial.h | 9 +++++++++
2 files changed, 44 insertions(+), 10 deletions(-)
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 1b7331e40d79..e09354e6bcb7 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -93,6 +93,10 @@ static u16 pl011_std_offsets[REG_ARRAY_SIZE] = {
struct vendor_data {
const u16 *reg_offset;
unsigned int ifls;
+ unsigned int fr_busy;
+ unsigned int fr_dsr;
+ unsigned int fr_cts;
+ unsigned int fr_ri;
bool access_32b;
bool oversampling;
bool dma_threshold;
@@ -111,6 +115,10 @@ static unsigned int get_fifosize_arm(struct amba_device *dev)
static struct vendor_data vendor_arm = {
.reg_offset = pl011_std_offsets,
.ifls = UART011_IFLS_RX4_8|UART011_IFLS_TX4_8,
+ .fr_busy = UART01x_FR_BUSY,
+ .fr_dsr = UART01x_FR_DSR,
+ .fr_cts = UART01x_FR_CTS,
+ .fr_ri = UART011_FR_RI,
.oversampling = false,
.dma_threshold = false,
.cts_event_workaround = false,
@@ -121,6 +129,10 @@ static struct vendor_data vendor_arm = {
static struct vendor_data vendor_sbsa = {
.reg_offset = pl011_std_offsets,
+ .fr_busy = UART01x_FR_BUSY,
+ .fr_dsr = UART01x_FR_DSR,
+ .fr_cts = UART01x_FR_CTS,
+ .fr_ri = UART011_FR_RI,
.access_32b = true,
.oversampling = false,
.dma_threshold = false,
@@ -164,6 +176,10 @@ static unsigned int get_fifosize_st(struct amba_device *dev)
static struct vendor_data vendor_st = {
.reg_offset = pl011_st_offsets,
.ifls = UART011_IFLS_RX_HALF|UART011_IFLS_TX_HALF,
+ .fr_busy = UART01x_FR_BUSY,
+ .fr_dsr = UART01x_FR_DSR,
+ .fr_cts = UART01x_FR_CTS,
+ .fr_ri = UART011_FR_RI,
.oversampling = true,
.dma_threshold = true,
.cts_event_workaround = true,
@@ -192,6 +208,10 @@ static struct vendor_data vendor_zte __maybe_unused = {
.reg_offset = pl011_zte_offsets,
.access_32b = true,
.ifls = UART011_IFLS_RX4_8|UART011_IFLS_TX4_8,
+ .fr_busy = ZX_UART01x_FR_BUSY,
+ .fr_dsr = ZX_UART01x_FR_DSR,
+ .fr_cts = ZX_UART01x_FR_CTS,
+ .fr_ri = ZX_UART011_FR_RI,
.get_fifosize = get_fifosize_arm,
};
@@ -1167,7 +1187,7 @@ static void pl011_dma_shutdown(struct uart_amba_port *uap)
return;
/* Disable RX and TX DMA */
- while (pl011_read(uap, REG_FR) & UART01x_FR_BUSY)
+ while (pl011_read(uap, REG_FR) & uap->vendor->fr_busy)
cpu_relax();
spin_lock_irq(&uap->port.lock);
@@ -1416,11 +1436,12 @@ static void pl011_modem_status(struct uart_amba_port *uap)
if (delta & UART01x_FR_DCD)
uart_handle_dcd_change(&uap->port, status & UART01x_FR_DCD);
- if (delta & UART01x_FR_DSR)
+ if (delta & uap->vendor->fr_dsr)
uap->port.icount.dsr++;
- if (delta & UART01x_FR_CTS)
- uart_handle_cts_change(&uap->port, status & UART01x_FR_CTS);
+ if (delta & uap->vendor->fr_cts)
+ uart_handle_cts_change(&uap->port,
+ status & uap->vendor->fr_cts);
wake_up_interruptible(&uap->port.state->port.delta_msr_wait);
}
@@ -1493,7 +1514,8 @@ static unsigned int pl011_tx_empty(struct uart_port *port)
struct uart_amba_port *uap =
container_of(port, struct uart_amba_port, port);
unsigned int status = pl011_read(uap, REG_FR);
- return status & (UART01x_FR_BUSY|UART01x_FR_TXFF) ? 0 : TIOCSER_TEMT;
+ return status & (uap->vendor->fr_busy | UART01x_FR_TXFF) ?
+ 0 : TIOCSER_TEMT;
}
static unsigned int pl011_get_mctrl(struct uart_port *port)
@@ -1508,9 +1530,9 @@ static unsigned int pl011_get_mctrl(struct uart_port *port)
result |= tiocmbit
TIOCMBIT(UART01x_FR_DCD, TIOCM_CAR);
- TIOCMBIT(UART01x_FR_DSR, TIOCM_DSR);
- TIOCMBIT(UART01x_FR_CTS, TIOCM_CTS);
- TIOCMBIT(UART011_FR_RI, TIOCM_RNG);
+ TIOCMBIT(uap->vendor->fr_dsr, TIOCM_DSR);
+ TIOCMBIT(uap->vendor->fr_cts, TIOCM_CTS);
+ TIOCMBIT(uap->vendor->fr_ri, TIOCM_RNG);
#undef TIOCMBIT
return result;
}
@@ -2191,7 +2213,7 @@ pl011_console_write(struct console *co, const char *s, unsigned int count)
* Finally, wait for transmitter to become empty
* and restore the TCR
*/
- while (pl011_read(uap, REG_FR) & UART01x_FR_BUSY)
+ while (pl011_read(uap, REG_FR) & uap->vendor->fr_busy)
cpu_relax();
if (!uap->vendor->always_enabled)
pl011_write(old_cr, uap, REG_CR);
@@ -2303,13 +2325,16 @@ static struct console amba_console = {
static void pl011_putc(struct uart_port *port, int c)
{
+ struct uart_amba_port *uap =
+ container_of(port, struct uart_amba_port, port);
+
while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF)
cpu_relax();
if (port->iotype == UPIO_MEM32)
writel(c, port->membase + UART01x_DR);
else
writeb(c, port->membase + UART01x_DR);
- while (readl(port->membase + UART01x_FR) & UART01x_FR_BUSY)
+ while (readl(port->membase + UART01x_FR) & uap->vendor->fr_busy)
cpu_relax();
}
diff --git a/include/linux/amba/serial.h b/include/linux/amba/serial.h
index d76a19ba2cff..ad0965e21a5e 100644
--- a/include/linux/amba/serial.h
+++ b/include/linux/amba/serial.h
@@ -104,6 +104,15 @@
#define UART01x_FR_CTS 0x001
#define UART01x_FR_TMSK (UART01x_FR_TXFF + UART01x_FR_BUSY)
+/*
+ * Some bits of Flag Register on ZTE device have different position from
+ * standard ones.
+ */
+#define ZX_UART01x_FR_BUSY 0x100
+#define ZX_UART01x_FR_DSR 0x008
+#define ZX_UART01x_FR_CTS 0x002
+#define ZX_UART011_FR_RI 0x001
+
#define UART011_CR_CTSEN 0x8000 /* CTS hardware flow control */
#define UART011_CR_RTSEN 0x4000 /* RTS hardware flow control */
#define UART011_CR_OUT2 0x2000 /* OUT2 */
--
1.9.1
--
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