From: Soren Brinkmann <soren.brinkmann@xilinx.com>
To: Russell King <linux@arm.linux.org.uk>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jslaby@suse.cz>,
One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Cc: Michal Simek <michal.simek@xilinx.com>,
Peter Crosthwaite <peter.crosthwaite@xilinx.com>,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-serial@vger.kernel.org, Rob Herring <robh+dt@kernel.org>,
Pawel Moll <pawel.moll@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Ian Campbell <ijc+devicetree@hellion.org.uk>,
Kumar Gala <galak@codeaurora.org>, Rob Landley <rob@landley.net>,
Grant Likely <grant.likely@linaro.org>,
devicetree@vger.kernel.org, linux-doc@vger.kernel.org,
Soren Brinkmann <soren.brinkmann@xilinx.com>
Subject: [PATCH 3/7] tty: xuartps: Refactor read-modify-writes
Date: Mon, 10 Mar 2014 14:21:14 -0700 [thread overview]
Message-ID: <1394486478-31037-4-git-send-email-soren.brinkmann@xilinx.com> (raw)
In-Reply-To: <1394486478-31037-1-git-send-email-soren.brinkmann@xilinx.com>
A lot of read-modify-write sequences used a one-line statement which
nests a readl() within a writel(). Convert this into code sequences that
make the three steps more obvious.
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
---
drivers/tty/serial/xilinx_uartps.c | 52 ++++++++++++++++++--------------------
1 file changed, 24 insertions(+), 28 deletions(-)
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index b00060052316..a4bd6242e72d 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -437,9 +437,9 @@ static int xuartps_clk_notifier_cb(struct notifier_block *nb,
spin_lock_irqsave(&xuartps->port->lock, flags);
/* Disable the TX and RX to set baud rate */
- xuartps_writel(xuartps_readl(XUARTPS_CR_OFFSET) |
- (XUARTPS_CR_TX_DIS | XUARTPS_CR_RX_DIS),
- XUARTPS_CR_OFFSET);
+ ctrl_reg = xuartps_readl(XUARTPS_CR_OFFSET);
+ ctrl_reg |= XUARTPS_CR_TX_DIS | XUARTPS_CR_RX_DIS;
+ xuartps_writel(ctrl_reg, XUARTPS_CR_OFFSET);
spin_unlock_irqrestore(&xuartps->port->lock, flags);
@@ -464,9 +464,9 @@ static int xuartps_clk_notifier_cb(struct notifier_block *nb,
spin_lock_irqsave(&xuartps->port->lock, flags);
/* Set TX/RX Reset */
- xuartps_writel(xuartps_readl(XUARTPS_CR_OFFSET) |
- (XUARTPS_CR_TXRST | XUARTPS_CR_RXRST),
- XUARTPS_CR_OFFSET);
+ ctrl_reg = xuartps_readl(XUARTPS_CR_OFFSET);
+ ctrl_reg |= XUARTPS_CR_TXRST | XUARTPS_CR_RXRST;
+ xuartps_writel(ctrl_reg, XUARTPS_CR_OFFSET);
while (xuartps_readl(XUARTPS_CR_OFFSET) &
(XUARTPS_CR_TXRST | XUARTPS_CR_RXRST))
@@ -479,10 +479,9 @@ static int xuartps_clk_notifier_cb(struct notifier_block *nb,
*/
xuartps_writel(rx_timeout, XUARTPS_RXTOUT_OFFSET);
ctrl_reg = xuartps_readl(XUARTPS_CR_OFFSET);
- xuartps_writel(
- (ctrl_reg & ~(XUARTPS_CR_TX_DIS | XUARTPS_CR_RX_DIS)) |
- (XUARTPS_CR_TX_EN | XUARTPS_CR_RX_EN),
- XUARTPS_CR_OFFSET);
+ ctrl_reg &= ~(XUARTPS_CR_TX_DIS | XUARTPS_CR_RX_DIS);
+ ctrl_reg |= XUARTPS_CR_TX_EN | XUARTPS_CR_RX_EN;
+ xuartps_writel(ctrl_reg, XUARTPS_CR_OFFSET);
spin_unlock_irqrestore(&xuartps->port->lock, flags);
@@ -631,9 +630,9 @@ static void xuartps_set_termios(struct uart_port *port,
}
/* Disable the TX and RX to set baud rate */
- xuartps_writel(xuartps_readl(XUARTPS_CR_OFFSET) |
- (XUARTPS_CR_TX_DIS | XUARTPS_CR_RX_DIS),
- XUARTPS_CR_OFFSET);
+ ctrl_reg = xuartps_readl(XUARTPS_CR_OFFSET);
+ ctrl_reg |= XUARTPS_CR_TX_DIS | XUARTPS_CR_RX_DIS;
+ xuartps_writel(ctrl_reg, XUARTPS_CR_OFFSET);
/*
* Min baud rate = 6bps and Max Baud Rate is 10Mbps for 100Mhz clk
@@ -651,20 +650,18 @@ static void xuartps_set_termios(struct uart_port *port,
uart_update_timeout(port, termios->c_cflag, baud);
/* Set TX/RX Reset */
- xuartps_writel(xuartps_readl(XUARTPS_CR_OFFSET) |
- (XUARTPS_CR_TXRST | XUARTPS_CR_RXRST),
- XUARTPS_CR_OFFSET);
-
ctrl_reg = xuartps_readl(XUARTPS_CR_OFFSET);
+ ctrl_reg |= XUARTPS_CR_TXRST | XUARTPS_CR_RXRST;
+ xuartps_writel(ctrl_reg, XUARTPS_CR_OFFSET);
/*
* Clear the RX disable and TX disable bits and then set the TX enable
* bit and RX enable bit to enable the transmitter and receiver.
*/
- xuartps_writel(
- (ctrl_reg & ~(XUARTPS_CR_TX_DIS | XUARTPS_CR_RX_DIS))
- | (XUARTPS_CR_TX_EN | XUARTPS_CR_RX_EN),
- XUARTPS_CR_OFFSET);
+ ctrl_reg = xuartps_readl(XUARTPS_CR_OFFSET);
+ ctrl_reg &= ~(XUARTPS_CR_TX_DIS | XUARTPS_CR_RX_DIS);
+ ctrl_reg |= XUARTPS_CR_TX_EN | XUARTPS_CR_RX_EN;
+ xuartps_writel(ctrl_reg, XUARTPS_CR_OFFSET);
xuartps_writel(rx_timeout, XUARTPS_RXTOUT_OFFSET);
@@ -1245,9 +1242,9 @@ static int xuartps_resume(struct device *device)
spin_lock_irqsave(&port->lock, flags);
/* Set TX/RX Reset */
- xuartps_writel(xuartps_readl(XUARTPS_CR_OFFSET) |
- (XUARTPS_CR_TXRST | XUARTPS_CR_RXRST),
- XUARTPS_CR_OFFSET);
+ ctrl_reg = xuartps_readl(XUARTPS_CR_OFFSET);
+ ctrl_reg |= XUARTPS_CR_TXRST | XUARTPS_CR_RXRST;
+ xuartps_writel(ctrl_reg, XUARTPS_CR_OFFSET);
while (xuartps_readl(XUARTPS_CR_OFFSET) &
(XUARTPS_CR_TXRST | XUARTPS_CR_RXRST))
cpu_relax();
@@ -1256,10 +1253,9 @@ static int xuartps_resume(struct device *device)
xuartps_writel(rx_timeout, XUARTPS_RXTOUT_OFFSET);
/* Enable Tx/Rx */
ctrl_reg = xuartps_readl(XUARTPS_CR_OFFSET);
- xuartps_writel(
- (ctrl_reg & ~(XUARTPS_CR_TX_DIS | XUARTPS_CR_RX_DIS)) |
- (XUARTPS_CR_TX_EN | XUARTPS_CR_RX_EN),
- XUARTPS_CR_OFFSET);
+ ctrl_reg &= ~(XUARTPS_CR_TX_DIS | XUARTPS_CR_RX_DIS);
+ ctrl_reg |= XUARTPS_CR_TX_EN | XUARTPS_CR_RX_EN;
+ xuartps_writel(ctrl_reg, XUARTPS_CR_OFFSET);
spin_unlock_irqrestore(&port->lock, flags);
} else {
--
1.9.0.1.g4196000
next prev parent reply other threads:[~2014-03-10 21:21 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-10 21:21 [PATCH 0/7] tty: xuartps: Rebranding + DT documentation Soren Brinkmann
2014-03-10 21:21 ` [PATCH 1/7] tty: xuartps: Clean up Soren Brinkmann
2014-03-10 21:21 ` [PATCH 2/7] tty: xuartps: Print warning in clock notifier Soren Brinkmann
2014-03-10 21:21 ` Soren Brinkmann [this message]
2014-03-10 21:21 ` [PATCH 4/7] tty: xuartps: Don't write IRQ disable register to enable interrupts Soren Brinkmann
2014-03-10 21:21 ` [PATCH 5/7] tty: xuartps: Rebrand driver as Cadence UART Soren Brinkmann
2014-03-10 21:21 ` [PATCH 6/7] tty: cadence: Document DT binding Soren Brinkmann
2014-03-10 21:21 ` [PATCH 7/7] ARM: zynq: DT: Migrate UART to Cadence binding Soren Brinkmann
2014-03-10 21:36 ` [PATCH 0/7] tty: xuartps: Rebranding + DT documentation Sören Brinkmann
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