[PATCH v9 1/3] serial: 8250_dw: Avoid serial_outx code duplicate with new dw8250_check_lcr()

From: Noam Camus
Date: Sat Dec 12 2015 - 12:19:51 EST


From: Noam Camus <noamc@xxxxxxxxxx>

With the help of Heikki we take common code that
makes sure LCR write wasn't ignored and put it in new function called
dw8250_check_lcr(). This function serves 3 serial_out routines:
dw8250_serial_out(), dw8250_serial_out32(), and dw8250_serial_outq().

This patch only brings better code reuse.

Signed-off-by: Noam Camus <noamc@xxxxxxxxxx>
Cc: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/tty/serial/8250/8250_dw.c | 91 +++++++++++++++++--------------------
1 files changed, 42 insertions(+), 49 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index a5d319e..ffe5e0c 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -95,25 +95,43 @@ static void dw8250_force_idle(struct uart_port *p)
(void)p->serial_in(p, UART_RX);
}

-static void dw8250_serial_out(struct uart_port *p, int offset, int value)
+static void dw8250_check_lcr(struct uart_port *p, int value)
{
- writeb(value, p->membase + (offset << p->regshift));
+ void __iomem *offset = p->membase + (UART_LCR << p->regshift);
+ int tries = 1000;

/* Make sure LCR write wasn't ignored */
- if (offset == UART_LCR) {
- int tries = 1000;
- while (tries--) {
- unsigned int lcr = p->serial_in(p, UART_LCR);
- if ((value & ~UART_LCR_SPAR) == (lcr & ~UART_LCR_SPAR))
- return;
- dw8250_force_idle(p);
- writeb(value, p->membase + (UART_LCR << p->regshift));
- }
- /*
- * FIXME: this deadlocks if port->lock is already held
- * dev_err(p->dev, "Couldn't set LCR to %d\n", value);
- */
+ while (tries--) {
+ unsigned int lcr = p->serial_in(p, UART_LCR);
+
+ if ((value & ~UART_LCR_SPAR) == (lcr & ~UART_LCR_SPAR))
+ return;
+
+ dw8250_force_idle(p);
+
+#ifdef CONFIG_64BIT
+ __raw_writeq(value & 0xff, offset);
+#else
+ if (p->iotype == UPIO_MEM32)
+ writel(value, offset);
+ else
+ writeb(value, offset);
+#endif
}
+ /*
+ * FIXME: this deadlocks if port->lock is already held
+ * dev_err(p->dev, "Couldn't set LCR to %d\n", value);
+ */
+}
+
+static void dw8250_serial_out(struct uart_port *p, int offset, int value)
+{
+ struct dw8250_data *d = p->private_data;
+
+ writeb(value, p->membase + (offset << p->regshift));
+
+ if (offset == UART_LCR && !d->uart_16550_compatible)
+ dw8250_check_lcr(p, value);
}

static unsigned int dw8250_serial_in(struct uart_port *p, int offset)
@@ -135,49 +153,26 @@ static unsigned int dw8250_serial_inq(struct uart_port *p, int offset)

static void dw8250_serial_outq(struct uart_port *p, int offset, int value)
{
+ struct dw8250_data *d = p->private_data;
+
value &= 0xff;
__raw_writeq(value, p->membase + (offset << p->regshift));
/* Read back to ensure register write ordering. */
__raw_readq(p->membase + (UART_LCR << p->regshift));

- /* Make sure LCR write wasn't ignored */
- if (offset == UART_LCR) {
- int tries = 1000;
- while (tries--) {
- unsigned int lcr = p->serial_in(p, UART_LCR);
- if ((value & ~UART_LCR_SPAR) == (lcr & ~UART_LCR_SPAR))
- return;
- dw8250_force_idle(p);
- __raw_writeq(value & 0xff,
- p->membase + (UART_LCR << p->regshift));
- }
- /*
- * FIXME: this deadlocks if port->lock is already held
- * dev_err(p->dev, "Couldn't set LCR to %d\n", value);
- */
- }
+ if (offset == UART_LCR && !d->uart_16550_compatible)
+ dw8250_check_lcr(p, value);
}
#endif /* CONFIG_64BIT */

static void dw8250_serial_out32(struct uart_port *p, int offset, int value)
{
+ struct dw8250_data *d = p->private_data;
+
writel(value, p->membase + (offset << p->regshift));

- /* Make sure LCR write wasn't ignored */
- if (offset == UART_LCR) {
- int tries = 1000;
- while (tries--) {
- unsigned int lcr = p->serial_in(p, UART_LCR);
- if ((value & ~UART_LCR_SPAR) == (lcr & ~UART_LCR_SPAR))
- return;
- dw8250_force_idle(p);
- writel(value, p->membase + (UART_LCR << p->regshift));
- }
- /*
- * FIXME: this deadlocks if port->lock is already held
- * dev_err(p->dev, "Couldn't set LCR to %d\n", value);
- */
- }
+ if (offset == UART_LCR && !d->uart_16550_compatible)
+ dw8250_check_lcr(p, value);
}

static unsigned int dw8250_serial_in32(struct uart_port *p, int offset)
@@ -463,10 +458,8 @@ static int dw8250_probe(struct platform_device *pdev)
dw8250_quirks(p, data);

/* If the Busy Functionality is not implemented, don't handle it */
- if (data->uart_16550_compatible) {
- p->serial_out = NULL;
+ if (data->uart_16550_compatible)
p->handle_irq = NULL;
- }

if (!data->skip_autocfg)
dw8250_setup_port(p);
--
1.7.1

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