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Message-ID: <1394173606.16156.51.camel@joe-AO722>
Date: Thu, 06 Mar 2014 22:26:46 -0800
From: Joe Perches <joe@...ches.com>
To: Greg KH <gregkh@...uxfoundation.org>
Cc: jon@...gle.org, jslaby@...e.cz, linux-kernel@...r.kernel.org,
linux-serial@...r.kernel.org, Jon Ringle <jringle@...dpoint.com>
Subject: Re: [PATCH] RFC: WIP: sc16is7xx.c
On Thu, 2014-03-06 at 21:52 -0800, Greg KH wrote:
> On Thu, Mar 06, 2014 at 09:35:46PM -0500, jon@...gle.org wrote:
> > From: Jon Ringle <jringle@...dpoint.com>
> >
> > I am requesting comments on this serial driver.
> > I am currently having some latency issues with it where I experience
> > packet loss at speed of 19200.
> >
> > I welcome any and all comments.
>
> The basic coding style problems make it hard to read to be able to help
> review it, sorry.
>
> Yes, brains have patterns, you want to follow the same patterns as
> others, it matters.
Here's a patternizing patch on top of this...
It's an extended version of what I sent Jon privately.
Mostly whitespace but some other neatening too.
Brace removals, tabifying, 80 column comments,
spelling typos, pr_<level>, c90 comments, etc.
I don't care that's it does a lot of things in
a single patch because this hasn't ever been
submitted before and I hope Jon rolls it into
his next submission.
---
drivers/tty/serial/sc16is7xx.c | 485 +++++++++++++++++++++--------------------
1 file changed, 253 insertions(+), 232 deletions(-)
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 5daed84..045241e 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -1,28 +1,34 @@
/*
- * The SC16IS740/750/760 is a slave I2C-bus/SPI interface to a single-channel high
- * performance UART. The SC16IS740/750/760’s internal register set is backward-compatible
- * with the widely used and widely popular 16C450. The SC16IS740/750/760 also provides
- * additional advanced features such as auto hardware and software flow control, automatic
- * RS-485 support, and software reset.
- *
- * Copyright (C) 2014 GridPoint
+ * SC16IS740/750/760 tty serial driver - Copyright (C) 2014 GridPoint
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
+ * The SC16IS740/750/760 is a slave I2C-bus/SPI interface to a single-channel
+ * high performance UART. The SC16IS740/750/760’s internal register set is
+ * backward-compatible with the widely used and widely popular 16C450.
+ *
+ * The SC16IS740/750/760 also provides additional advanced features such as
+ * auto hardware and software flow control, automatic RS-485 support, and
+ * software reset.
+ *
* Notes:
+ *
* The sc16is740 driver is used for the GPEC RS485 Half duplex communication.
- * In the EC1K board the sc16is740 RTS line is connected to the SN65HVD1780DR chip and which
- * is used to signal the RS485 diretion. When the RTS is low the RS485 direction is set to
- * output from the CPU.
- * To set the RS485 diretion we use the sc16is740 internal RS485 feature where the chip drives
- * the RTS line when the data is written to the TX FIFO (see the spec note for the EFCR[4] bit
- * configuration).
*
+ * In the EC1K board the sc16is740 RTS line is connected to a SN65HVD1780DR
+ * chip which is used to signal the RS485 direction.
+ * When RTS is low, the RS485 direction is set to output from the CPU.
+ *
+ * To set the RS485 direction we use the sc16is740 internal RS485 feature
+ * where the chip drives the RTS line when the data is written to the TX FIFO
+ * (see the spec note for the EFCR[4] bit configuration).
*/
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/gpio.h>
@@ -39,116 +45,139 @@
#include <linux/tty_flip.h>
#include <linux/wait.h>
-#define DRV_VERSION "0.3"
-#define DRV_NAME "sc16is7xx"
-#define DEV_NAME "ttySC"
-#define SC16IS7XX_MAJOR 204 /* Take place of the /dev/ttySC0 SCI serial port 0 */
-#define SC16IS7XX_MINOR 8
+#define DRV_VERSION "0.3"
+#define DRV_NAME "sc16is7xx"
+#define DEV_NAME "ttySC"
+
+#define SC16IS7XX_MAJOR 204 /* Take place of the /dev/ttySC0
+ * SCI serial port 0
+ */
+#define SC16IS7XX_MINOR 8
/*
* Software Definitions
*/
/* Commands sent from the uart callbacks to the work handler */
-#define SC16IS7XX_CMND_STOP_RX (0) /* Disable the RX interrupt */
-#define SC16IS7XX_CMND_START_TX (1) /* Enable the TX holding register empty interrupt */
-#define SC16IS7XX_CMND_STOP_TX (2) /* Disable the TX holding register empty interrupt */
-#define SC16IS7XX_CMND_NEW_TERMIOS (3) /* Apply new termios configuration */
-#define SC16IS7XX_CMND_BREAK_CTRL (4)
-#define SC16IS7XX_CMND_TX_RX (5)
-
-#define SC16IS7XX_CLEAR_FIFO_ON_TX /* If defined controller will clear tx fifo before it transmits chars */
+#define SC16IS7XX_CMND_STOP_RX (0) /* Disable the RX interrupt */
+#define SC16IS7XX_CMND_START_TX (1) /* Enable the TX holding register
+ * empty interrupt
+ */
+#define SC16IS7XX_CMND_STOP_TX (2) /* Disable the TX holding register
+ * empty interrupt
+ */
+#define SC16IS7XX_CMND_NEW_TERMIOS (3) /* Apply termios configuration */
+#define SC16IS7XX_CMND_BREAK_CTRL (4)
+#define SC16IS7XX_CMND_TX_RX (5)
+
+#define SC16IS7XX_CLEAR_FIFO_ON_TX /* If defined controller will clear
+ * tx fifo before it transmits chars
+ */
/*
* SC16IS7XX Hardware Definitions
*/
-#define DA850_RS485_INT_PIN GPIO_TO_PIN(0,4)
+#define DA850_RS485_INT_PIN GPIO_TO_PIN(0, 4)
-#define SC16IS7XX_CLK 7372800 /* crystal clock connected to the SC16IS7XX chip */
-#define SC16IS7XX_DEFAULT_BAUDRATE 19200
+#define SC16IS7XX_CLK 7372800 /* crystal clock connected
+ * to the SC16IS7XX chip
+ */
+#define SC16IS7XX_DEFAULT_BAUDRATE 19200
/* General registers set */
-#define SC16IS7XX_TCR 0x06
-#define SC16IS7XX_TLR 0x07
-#define SC16IS7XX_TXLVL 0x08
-#define SC16IS7XX_RXLVL 0x09
-#define SC16IS7XX_EFCR 0x0F
+#define SC16IS7XX_TCR 0x06
+#define SC16IS7XX_TLR 0x07
+#define SC16IS7XX_TXLVL 0x08
+#define SC16IS7XX_RXLVL 0x09
+#define SC16IS7XX_EFCR 0x0F
/* LCR / MCR configurations */
-#define UART_LCR_8N1 UART_LCR_WLEN8
+#define UART_LCR_8N1 UART_LCR_WLEN8
-#define SC16IS7XX_LCRVAL UART_LCR_8N1 /* 8 data, 1 stop, no parity */
-#define SC16IS7XX_MCRVAL (UART_MCR_DTR|UART_MCR_RTS) /* clock divisor = 1,UART mode,lpback disabled,RTS/DTR are set,TCR/TLR disabled */
+#define SC16IS7XX_LCRVAL UART_LCR_8N1 /* 8 data, 1 stop, no parity */
+#define SC16IS7XX_MCRVAL (UART_MCR_DTR | UART_MCR_RTS)
+ /* clock divisor = 1,
+ * UART mode,
+ * loopback disabled,
+ * RTS/DTR are set,
+ * TCR/TLR disabled
+ */
/* SC16IS7XX Internal register address translation */
-#define REG_TO_I2C_ADDR(reg) (((reg) & 0x0f) << 3)
-
-#define SC16IS7XX_FIFO_SIZE 64 /* Rx fifo size */
+#define REG_TO_I2C_ADDR(reg) (((reg) & 0x0f) << 3)
-#define SC16IS7XX_LOAD_SIZE 64 /* Tx fifo size */
+#define SC16IS7XX_FIFO_SIZE 64 /* Rx fifo size */
+#define SC16IS7XX_LOAD_SIZE 64 /* Tx fifo size */
struct uart_sc16is7xx_port {
struct uart_port port;
/* private to the driver */
- struct i2c_client* client; /* I2C client handle */
+ struct i2c_client *client; /* I2C client handle */
- int tx_empty; /* last TX empty bit */
+ int tx_empty; /* last TX empty bit */
- unsigned long command; /* Command to the work executed from the workqueue */
+ unsigned long command; /* Command to the work executed
+ * from the workqueue
+ */
- struct ktermios* termios_new;
- struct ktermios* termios_old;
+ struct ktermios *termios_new;
+ struct ktermios *termios_old;
int break_state;
- char ier; /* cache Interrupt Enable Register to manage the interrupt from the work */
+ char ier; /* cache Interrupt Enable Register to
+ * manage the interrupt from the work
+ */
char lcr;
- char fcr; /* cache the FIFO control register to hold write only values of that register */
+ char fcr; /* cache the FIFO control register to
+ * hold write only values of that register
+ */
spinlock_t lock;
/* set to 1 to make the workhandler exit as soon as possible */
- int force_end_work;
+ int force_end_work;
};
-static inline unsigned char sc16is7xx_read_reg(struct uart_sc16is7xx_port* up, unsigned char reg)
+static inline unsigned char sc16is7xx_read_reg(struct uart_sc16is7xx_port *up,
+ unsigned char reg)
{
int rc;
u8 val = 0;
-
u8 sc_reg = REG_TO_I2C_ADDR(reg);
rc = i2c_master_send(up->client, &sc_reg, 1);
- if(rc < 0)
- {
- dev_err(&up->client->dev,"%s I2C error writing the i2c client rc = %d\n",__FUNCTION__, rc);
+ if (rc < 0) {
+ dev_err(&up->client->dev,
+ "%s I2C error writing the i2c client rc = %d\n",
+ __func__, rc);
goto out;
}
rc = i2c_master_recv(up->client, &val, 1);
- if(rc < 0)
- {
- dev_err(&up->client->dev,"%s I2C error reading from the i2c client rc = %d\n",__FUNCTION__, rc);
- }
+ if (rc < 0)
+ dev_err(&up->client->dev,
+ "%s I2C error reading from the i2c client rc = %d\n",
+ __func__, rc);
out:
return val;
}
-static inline void sc16is7xx_write_reg(struct uart_sc16is7xx_port *up, unsigned char reg, unsigned char value)
+static inline void sc16is7xx_write_reg(struct uart_sc16is7xx_port *up,
+ unsigned char reg, unsigned char value)
{
int rc;
-
u8 msg[2];
msg[0] = REG_TO_I2C_ADDR(reg);
msg[1] = value;
rc = i2c_master_send(up->client, msg, 2);
- if(rc < 0)
- {
- dev_err(&up->client->dev,"%s I2C error writing the i2c client rc = %d\n",__FUNCTION__, rc);
- }
+ if (rc < 0)
+ dev_err(&up->client->dev,
+ "%s I2C error writing the i2c client rc = %d\n",
+ __func__, rc);
}
static void sc16is7xx_enable_irq(struct uart_sc16is7xx_port *up, int mask)
@@ -163,45 +192,54 @@ static void sc16is7xx_disable_irq(struct uart_sc16is7xx_port *up, int mask)
sc16is7xx_write_reg(up, UART_IER, up->ier);
}
-
-static void sc16is7xx_set_baudrate(struct uart_sc16is7xx_port* up, int baudrate)
+static void sc16is7xx_set_baudrate(struct uart_sc16is7xx_port *up, int baudrate)
{
u8 lcr, ier;
u32 divisor;
ier = sc16is7xx_read_reg(up, UART_IER);
lcr = sc16is7xx_read_reg(up, UART_LCR);
- sc16is7xx_write_reg(up, UART_IER, 0x00); // Disable interrupts
- sc16is7xx_write_reg(up, SC16IS7XX_EFCR, 0x06 ); // Disable TX/RX
+ /* Disable interrupts */
+ sc16is7xx_write_reg(up, UART_IER, 0x00);
+
+ /* Disable TX/RX */
+ sc16is7xx_write_reg(up, SC16IS7XX_EFCR, 0x06);
- sc16is7xx_write_reg(up, UART_LCR, UART_LCR_CONF_MODE_B); // Open the LCR divisors for configuration
+ /* Open the LCR divisors for configuration */
+ sc16is7xx_write_reg(up, UART_LCR, UART_LCR_CONF_MODE_B);
- sc16is7xx_write_reg(up, UART_EFR, 0x10); // Enable enhanced features and internal clock divider
+ /* Enable enhanced features and internal clock divider */
+ sc16is7xx_write_reg(up, UART_EFR, 0x10);
- sc16is7xx_write_reg(up, UART_MCR, UART_MCR_CLKSEL|4); // Set the input clock divisor to 1
+ /* Set the input clock divisor to 1 */
+ sc16is7xx_write_reg(up, UART_MCR, UART_MCR_CLKSEL|4);
/* Get the baudrate divisor from the upper port layer */
divisor = uart_get_divisor(&up->port, baudrate);
- sc16is7xx_write_reg(up, UART_DLL, divisor & 0xff ); // Write the new divisor
+ /* Write the new divisor */
+ sc16is7xx_write_reg(up, UART_DLL, divisor & 0xff);
sc16is7xx_write_reg(up, UART_DLM, (divisor >> 8) & 0xff);
- sc16is7xx_write_reg(up, UART_LCR, lcr); // Put LCR back to the normal mode
+ /* Put LCR back to the normal mode */
+ sc16is7xx_write_reg(up, UART_LCR, lcr);
sc16is7xx_write_reg(up, SC16IS7XX_TLR, 0x0f);
+
+ /* Enable the FIFOs */
up->fcr = UART_FCR_ENABLE_FIFO;
- sc16is7xx_write_reg(up, UART_FCR, up->fcr); // Enable the FIFOs
+ sc16is7xx_write_reg(up, UART_FCR, up->fcr);
- sc16is7xx_write_reg(up, SC16IS7XX_EFCR, 0x10); // Enable the Rx and Tx and control the RTS (RS485_DIR) line
+ /* Enable the Rx and Tx and control the RTS (RS485_DIR) line */
+ sc16is7xx_write_reg(up, SC16IS7XX_EFCR, 0x10);
- sc16is7xx_write_reg(up, UART_IER, ier); // Restore the interrupts configuration
+ /* Restore the interrupts configuration */
+ sc16is7xx_write_reg(up, UART_IER, ier);
}
-/*
- * The function actually delivers the Tx characters to the HW
- */
-static void sc16is7xx_transmit_chars(struct uart_sc16is7xx_port* up)
+/* deliver the Tx characters to the HW */
+static void sc16is7xx_transmit_chars(struct uart_sc16is7xx_port *up)
{
struct circ_buf *xmit = &up->port.state->xmit;
int count;
@@ -215,6 +253,7 @@ static void sc16is7xx_transmit_chars(struct uart_sc16is7xx_port* up)
up->port.x_char = 0;
return;
}
+
if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
up->ier &= ~UART_IER_THRI;
return;
@@ -235,15 +274,13 @@ static void sc16is7xx_transmit_chars(struct uart_sc16is7xx_port* up)
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&up->port);
- if (uart_circ_empty(xmit)) {
+ if (uart_circ_empty(xmit))
up->ier &= ~UART_IER_THRI;
- }
}
-/*
- * The function actually receives the characters from the HW and transfers them up to the TTY layer.
- */
-static inline void sc16is7xx_receive_chars(struct uart_sc16is7xx_port *up, int *status)
+/* receives characters from the HW and transfer themto the TTY layer */
+static inline void sc16is7xx_receive_chars(struct uart_sc16is7xx_port *up,
+ int *status)
{
unsigned int ch, flag;
int chars = 0;
@@ -252,15 +289,13 @@ static inline void sc16is7xx_receive_chars(struct uart_sc16is7xx_port *up, int *
dev_dbg(&up->client->dev, "%s\n", __func__);
do {
- if (likely(*status & UART_LSR_DR)) {
+ if (likely(*status & UART_LSR_DR))
ch = sc16is7xx_read_reg(up, UART_RX);
- } else {
+ else
ch = 0xffff;
- }
- if (*status & up->port.ignore_status_mask) {
+ if (*status & up->port.ignore_status_mask)
goto ignore_char;
- }
flag = TTY_NORMAL;
up->port.icount.rx++;
@@ -273,64 +308,56 @@ static inline void sc16is7xx_receive_chars(struct uart_sc16is7xx_port *up, int *
*status &= ~(UART_LSR_FE | UART_LSR_PE);
up->port.icount.brk++;
/*
- * We do the SysRQ and SAK checking
- * here because otherwise the break
- * may get masked by ignore_status_mask
- * or read_status_mask.
+ * We do the SysRQ and SAK checking here
+ * because otherwise the break may get masked
+ * by ignore_status_mask or read_status_mask
*/
- if (uart_handle_break(&up->port)) {
+ if (uart_handle_break(&up->port))
goto ignore_char;
- }
} else if (*status & UART_LSR_PE) {
up->port.icount.parity++;
} else if (*status & UART_LSR_FE) {
up->port.icount.frame++;
}
- if (*status & UART_LSR_OE) {
+ if (*status & UART_LSR_OE)
up->port.icount.overrun++;
- }
- /*
- * Mask off conditions which should be ignored.
- */
+ /* Mask off conditions which should be ignored */
*status &= up->port.read_status_mask;
- if (*status & UART_LSR_BI) {
+ if (*status & UART_LSR_BI)
flag = TTY_BREAK;
- } else if (*status & UART_LSR_PE) {
+ else if (*status & UART_LSR_PE)
flag = TTY_PARITY;
- } else if (*status & UART_LSR_FE) {
+ else if (*status & UART_LSR_FE)
flag = TTY_FRAME;
- }
}
- if (unlikely(0xffff == ch)) {
+ if (unlikely(0xffff == ch))
goto ignore_char;
- }
- if (uart_handle_sysrq_char(&up->port, ch)) {
+ if (uart_handle_sysrq_char(&up->port, ch))
goto ignore_char;
- }
uart_insert_char(&up->port, *status, UART_LSR_OE, ch, flag);
chars++;
ignore_char:
*status = sc16is7xx_read_reg(up, UART_LSR);
- } while ((*status & (UART_LSR_DR | UART_LSR_BI)) && (max_count-- > 0) && !up->force_end_work);
+ } while ((*status & (UART_LSR_DR | UART_LSR_BI)) &&
+ (max_count-- > 0) && !up->force_end_work);
- dev_dbg(&up->client->dev, "%s RX:%d chars oe:%d\n", __func__, chars, up->port.icount.overrun);
+ dev_dbg(&up->client->dev, "%s RX:%d chars oe:%d\n",
+ __func__, chars, up->port.icount.overrun);
- if (chars > 0) {
+ if (chars > 0)
tty_flip_buffer_push(&(up->port.state->port));
- }
}
-static void
-sc16is7xx_set_termios_work(struct uart_sc16is7xx_port *up)
+static void sc16is7xx_set_termios_work(struct uart_sc16is7xx_port *up)
{
- struct ktermios* termios = up->termios_new;
- struct ktermios* old = up->termios_old;
+ struct ktermios *termios = up->termios_new;
+ struct ktermios *old = up->termios_old;
unsigned long flags;
unsigned char cval;
unsigned int baud;
@@ -347,8 +374,8 @@ sc16is7xx_set_termios_work(struct uart_sc16is7xx_port *up)
case CS7:
cval = UART_LCR_WLEN7;
break;
- default:
case CS8:
+ default:
cval = UART_LCR_WLEN8;
break;
}
@@ -362,29 +389,22 @@ sc16is7xx_set_termios_work(struct uart_sc16is7xx_port *up)
sc16is7xx_write_reg(up, UART_LCR, cval);
- /*
- * Ask the core to calculate the divisor for us.
- */
+ /* Ask the core to calculate the divisor for us */
baud = uart_get_baud_rate(&up->port, termios, old, 9600, 115200);
sc16is7xx_set_baudrate(up, baud);
- up->port.state->port.low_latency = 1; // Low latency since we Tx from the work queue
+ /* Low latency since we Tx from the work queue */
+ up->port.state->port.low_latency = 1;
- /*
- * Update the per-port timeout.
- */
+ /* Update the per-port timeout */
uart_update_timeout(&up->port, termios->c_cflag, baud);
- /*
- * ignore all characters if CREAD is not set
- */
+ /* ignore all characters if CREAD is not set */
if ((termios->c_cflag & CREAD) == 0)
up->port.ignore_status_mask |= UART_LSR_DR;
- if(tty_termios_baud_rate(termios))
- {
- tty_termios_encode_baud_rate(termios,baud,baud);
- }
+ if (tty_termios_baud_rate(termios))
+ tty_termios_encode_baud_rate(termios, baud, baud);
spin_unlock_irqrestore(&up->lock, flags);
}
@@ -395,53 +415,59 @@ static void sc16is7xx_work(struct uart_sc16is7xx_port *up)
up->ier = sc16is7xx_read_reg(up, UART_IER);
- /* We cannot handle the interrupts while in the work queue so we disable the RX interrupt.
- * It is ok because of during the reception of the characters we check the status of the
+ /*
+ * We cannot handle the interrupts while in the work queue so we
+ * disable the RX interrupt. It is ok because of during the
+ * reception of the characters we check the status of the
* interrupt register and process all incoming packets
*/
sc16is7xx_write_reg(up, UART_IER, 0x00);
- dev_dbg(&up->client->dev, "%s: start work command:%04lx ier:0x%02x\n", __func__, up->command, (int)up->ier);
+ dev_dbg(&up->client->dev, "%s: start work - command:%04lx ier:0x%02x\n",
+ __func__, up->command, (int)up->ier);
- if(test_and_clear_bit(SC16IS7XX_CMND_NEW_TERMIOS, &up->command)) {
+ if (test_and_clear_bit(SC16IS7XX_CMND_NEW_TERMIOS, &up->command)) {
dev_dbg(&up->client->dev, "CMND_NEW_TERMIOS\n");
/* User requested the changes in the Terminal Configurations */
sc16is7xx_set_termios_work(up);
}
- if(test_and_clear_bit(SC16IS7XX_CMND_BREAK_CTRL, &up->command)) {
- if (up->break_state == -1) {
+ if (test_and_clear_bit(SC16IS7XX_CMND_BREAK_CTRL, &up->command)) {
+ if (up->break_state == -1)
up->lcr |= UART_LCR_SBC;
- } else {
+ else
up->lcr &= ~UART_LCR_SBC;
- }
sc16is7xx_write_reg(up, UART_LCR, up->lcr);
}
- if(test_and_clear_bit(SC16IS7XX_CMND_START_TX, &up->command)) {
+ if (test_and_clear_bit(SC16IS7XX_CMND_START_TX, &up->command)) {
dev_dbg(&up->client->dev, "CMND_START_TX\n");
/* Enable the Tx holding register empty interrupt */
up->ier |= UART_IER_THRI;
#ifdef SC16IS7XX_CLEAR_FIFO_ON_TX
/* Clear Tx Fifo to remove the junk characters if any */
- if(up->fcr & UART_FCR_ENABLE_FIFO) {
+ if (up->fcr & UART_FCR_ENABLE_FIFO) {
/* Fifo is enabled */
- sc16is7xx_write_reg(up, UART_FCR, up->fcr & UART_FCR_CLEAR_XMIT);
+ sc16is7xx_write_reg(up, UART_FCR,
+ up->fcr & UART_FCR_CLEAR_XMIT);
dev_dbg(&up->client->dev, "Clear FIFO\n");
}
#endif
}
- if(test_and_clear_bit(SC16IS7XX_CMND_STOP_TX, &up->command)) {
+ if (test_and_clear_bit(SC16IS7XX_CMND_STOP_TX, &up->command)) {
dev_dbg(&up->client->dev, "CMND_STOP_TX\n");
/* Disable the Tx holding register interrupt */
up->ier &= ~UART_IER_THRI;
}
- if(test_and_clear_bit(SC16IS7XX_CMND_STOP_RX, &up->command)) {
+ if (test_and_clear_bit(SC16IS7XX_CMND_STOP_RX, &up->command)) {
dev_dbg(&up->client->dev, "CMND_STOP_RX\n");
- /* User requested to stop the RX interrupt so we clear the interrupt enable register */
+ /*
+ * User requested to stop the RX interrupt so we clear the
+ * interrupt enable register
+ */
up->ier &= ~UART_IER_RDI;
}
@@ -449,35 +475,33 @@ static void sc16is7xx_work(struct uart_sc16is7xx_port *up)
lsr = sc16is7xx_read_reg(up, UART_LSR);
if ((lsr & (UART_LSR_DR | UART_LSR_BI)) && (up->ier & UART_IER_RDI)) {
sc16is7xx_receive_chars(up, &lsr);
- if (lsr & (UART_LSR_DR | UART_LSR_BI)) {
- /* There is more to receive */
+ /* check if there is more to receive */
+ if (lsr & (UART_LSR_DR | UART_LSR_BI))
set_bit(SC16IS7XX_CMND_TX_RX, &up->command);
- }
}
- if ((lsr & UART_LSR_THRE) && (up->ier & UART_IER_THRI)) {
+ if ((lsr & UART_LSR_THRE) && (up->ier & UART_IER_THRI))
sc16is7xx_transmit_chars(up);
- }
- if(sc16is7xx_read_reg(up, UART_LSR) & UART_LSR_THRE)
- {
- dev_dbg(&up->client->dev, "%s: TX_EMPTY\n", __FUNCTION__);
+ if (sc16is7xx_read_reg(up, UART_LSR) & UART_LSR_THRE) {
+ dev_dbg(&up->client->dev, "%s: TX_EMPTY\n", __func__);
up->tx_empty = TIOCSER_TEMT;
- }
- else
- {
- dev_dbg(&up->client->dev, "%s: TX_NOT_EMPTY\n", __FUNCTION__);
- up->tx_empty = 0; /* port is not ready to accept the new TX characters */
+ } else {
+ /* port is not ready to accept the new TX characters */
+ dev_dbg(&up->client->dev, "%s: TX_NOT_EMPTY\n", __func__);
+ up->tx_empty = 0;
}
- dev_dbg(&up->client->dev, "%s: end work ier 0x%02X\n", __func__, (int)up->ier);
+ dev_dbg(&up->client->dev, "%s: end work - ier 0x%02X\n",
+ __func__, (int)up->ier);
- sc16is7xx_write_reg(up, UART_IER, up->ier); /* Restore the interrupts */
+ /* Restore the interrupts */
+ sc16is7xx_write_reg(up, UART_IER, up->ier);
}
-static irqreturn_t sc16is7xx_ist(int irq, void* dev_id)
+static irqreturn_t sc16is7xx_ist(int irq, void *dev_id)
{
- struct uart_sc16is7xx_port* up = (struct uart_sc16is7xx_port *)dev_id;
+ struct uart_sc16is7xx_port *up = (struct uart_sc16is7xx_port *)dev_id;
unsigned long flags;
spin_lock_irqsave(&up->lock, flags);
@@ -491,18 +515,25 @@ static unsigned int sc16is7xx_tx_empty(struct uart_port *port)
{
struct uart_sc16is7xx_port *up = (struct uart_sc16is7xx_port *)port;
- dev_dbg(&up->client->dev, "%s:(%d)\n", __FUNCTION__, up->tx_empty);
+ dev_dbg(&up->client->dev, "%s:(%d)\n", __func__, up->tx_empty);
+
return up->tx_empty;
}
static void sc16is7xx_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
- /* Just a placeholder. We do not have modem control lines in our RS485 port */
+ /*
+ * Just a placeholder
+ * We do not have modem control lines in our RS485 port
+ */
}
static unsigned int sc16is7xx_get_mctrl(struct uart_port *port)
{
- /* Just a placeholder. We do not have modem control lines in our RS485 port */
+ /*
+ * Just a placeholder
+ * We do not have modem control lines in our RS485 port
+ */
return TIOCM_CAR | TIOCM_RNG | TIOCM_DSR | TIOCM_CTS;
}
@@ -548,7 +579,7 @@ static void sc16is7xx_stop_tx(struct uart_port *port)
spin_unlock_irqrestore(&up->lock, flags);
}
-static void sc16is7xxs_enable_ms(struct uart_port* port)
+static void sc16is7xxs_enable_ms(struct uart_port *port)
{
/* Do nothing */
}
@@ -560,7 +591,7 @@ static void sc16is7xx_break_ctl(struct uart_port *port, int break_state)
spin_lock_irqsave(&up->lock, flags);
- dev_dbg(&up->client->dev, "%s:(%d)\n", __FUNCTION__, break_state);
+ dev_dbg(&up->client->dev, "%s:(%d)\n", __func__, break_state);
up->break_state = break_state;
set_bit(SC16IS7XX_CMND_BREAK_CTRL, &up->command);
sc16is7xx_work(up);
@@ -577,18 +608,15 @@ static void sc16is7xx_shutdown(struct uart_port *port)
dev_dbg(&up->client->dev, "%s\n", __func__);
- /*
- * Disable interrupts from this port
- */
+ /* Disable interrupts from this port */
sc16is7xx_disable_irq(up, UART_IER_THRI | UART_IER_RDI);
- /*
- * Disable break condition and FIFOs
- */
- sc16is7xx_write_reg(up, UART_LCR, sc16is7xx_read_reg(up, UART_LCR) & ~UART_LCR_SBC);
- sc16is7xx_write_reg(up, UART_FCR, UART_FCR_ENABLE_FIFO |
- UART_FCR_CLEAR_RCVR |
- UART_FCR_CLEAR_XMIT);
+ /* Disable break condition and FIFOs */
+ sc16is7xx_write_reg(up, UART_LCR,
+ sc16is7xx_read_reg(up, UART_LCR) & ~UART_LCR_SBC);
+ sc16is7xx_write_reg(up, UART_FCR,
+ (UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR |
+ UART_FCR_CLEAR_XMIT));
sc16is7xx_write_reg(up, UART_FCR, 0);
spin_unlock_irqrestore(&up->lock, flags);
@@ -610,37 +638,37 @@ static int sc16is7xx_startup(struct uart_port *port)
up->break_state = -1;
up->tx_empty = TIOCSER_TEMT;
- // Disable IRQs to configure
+ /* Disable IRQs to configure */
sc16is7xx_write_reg(up, UART_IER, 0);
- /*
- * Now, initialize the UART
- */
+ /* Now, initialize the UART */
sc16is7xx_write_reg(up, UART_LCR, UART_LCR_8N1);
/*
- * Clear the FIFO buffers and disable them.
+ * Clear the FIFO buffers and disable them
* (they will be reenabled in set_termios())
*/
- while(sc16is7xx_read_reg(up, UART_LSR) & (UART_LSR_DR | UART_LSR_BI))
- {
- /* Empty the RX holding register to prevent printing stale characters on the screen */
+ while (sc16is7xx_read_reg(up, UART_LSR) & (UART_LSR_DR | UART_LSR_BI)) {
+ /*
+ * Empty the RX holding register to prevent printing
+ * stale characters on the screen
+ */
sc16is7xx_read_reg(up, UART_RX);
}
- /*
- * Finally, enable interrupts.
- */
+ /* Finally, enable interrupts */
sc16is7xx_enable_irq(up, UART_IER_RDI);
spin_unlock_irqrestore(&up->lock, flags);
+
return 0;
}
-static void
-sc16is7xx_set_termios(struct uart_port* port, struct ktermios* termios, struct ktermios* old)
+static void sc16is7xx_set_termios(struct uart_port *port,
+ struct ktermios *termios,
+ struct ktermios *old)
{
- struct uart_sc16is7xx_port * up = (struct uart_sc16is7xx_port *)port;
+ struct uart_sc16is7xx_port *up = (struct uart_sc16is7xx_port *)port;
unsigned long flags;
spin_lock_irqsave(&up->lock, flags);
@@ -678,15 +706,14 @@ static void sc16is7xx_config_port(struct uart_port *port, int flags)
up->port.type = PORT_SC16IS7XX;
}
-static int sc16is7xx_verify_port(struct uart_port *port, struct serial_struct *ser)
+static int sc16is7xx_verify_port(struct uart_port *port,
+ struct serial_struct *ser)
{
- int ret = -EINVAL;
-
if (ser->type == PORT_UNKNOWN || ser->type == PORT_SC16IS7XX)
- ret = 0;
- return ret;
-}
+ return 0;
+ return -EINVAL;
+}
static struct uart_ops sc16is7xx_ops = {
.tx_empty = sc16is7xx_tx_empty,
@@ -701,65 +728,61 @@ static struct uart_ops sc16is7xx_ops = {
.shutdown = sc16is7xx_shutdown,
.set_termios = sc16is7xx_set_termios,
.type = sc16is7xx_type,
- .release_port = sc16is7xx_release_port,
- .request_port = sc16is7xx_request_port,
+ .release_port = sc16is7xx_release_port,
+ .request_port = sc16is7xx_request_port,
.config_port = sc16is7xx_config_port,
.verify_port = sc16is7xx_verify_port,
};
static struct uart_driver sc16is7xx_uart_driver = {
.owner = THIS_MODULE,
- .driver_name = DRV_NAME,
- .dev_name = DEV_NAME,
- .major = SC16IS7XX_MAJOR,
- .minor = SC16IS7XX_MINOR,
- .nr = 1,
+ .driver_name = DRV_NAME,
+ .dev_name = DEV_NAME,
+ .major = SC16IS7XX_MAJOR,
+ .minor = SC16IS7XX_MINOR,
+ .nr = 1,
};
-static int uart_driver_registered = 0;
+
+static int uart_driver_registered;
static int sc16is7xx_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int retval;
- struct uart_sc16is7xx_port* up = NULL; /* user port */
+ struct uart_sc16is7xx_port *up = NULL; /* user port */
if (!uart_driver_registered) {
retval = uart_register_driver(&sc16is7xx_uart_driver);
if (retval) {
- printk(KERN_ERR "Couldn't register sc16is7xx uart driver\n");
+ pr_err("Couldn't register sc16is7xx uart driver\n");
return retval;
}
uart_driver_registered = 1;
}
- up = kzalloc(sizeof(struct uart_sc16is7xx_port), GFP_KERNEL);
- if (!up) {
- dev_warn(&client->dev,
- "kmalloc for sc16is7xx structure failed!\n");
+ up = kzalloc(sizeof(*up), GFP_KERNEL);
+ if (!up)
return -ENOMEM;
- }
/* First check if adaptor is OK and it supports our I2C functionality */
- if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
- {
- dev_err(&client->dev,"Can't find the sc16is7xx chip\n");
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+ dev_err(&client->dev, "Can't find the sc16is7xx chip\n");
retval = -ENODEV;
goto exit;
}
- dev_info(&client->dev,"chip found, driver version " DRV_VERSION "\n");
+ dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
/* Configure the GPIO IRQ line */
retval = gpio_request(DA850_RS485_INT_PIN, "SC16IS7xx INT");
-
- if(retval)
- {
- dev_err(&client->dev,"Can't request gpio interrupt pin \n");
+ if (retval) {
+ dev_err(&client->dev, "Can't request gpio interrupt pin\n");
retval = -EIO;
goto exit;
}
- gpio_direction_input(DA850_RS485_INT_PIN); // Set GPIO IRQ pin to be input
+ /* Set GPIO IRQ pin to be input */
+ gpio_direction_input(DA850_RS485_INT_PIN);
up->client = client;
@@ -768,8 +791,8 @@ static int sc16is7xx_probe(struct i2c_client *client,
up->port.uartclk = SC16IS7XX_CLK;
up->port.fifosize = SC16IS7XX_FIFO_SIZE;
up->port.ops = &sc16is7xx_ops;
- up->port.iotype = UPIO_PORT;
- up->port.flags = UPF_FIXED_TYPE | UPF_FIXED_PORT;
+ up->port.iotype = UPIO_PORT;
+ up->port.flags = UPF_FIXED_TYPE | UPF_FIXED_PORT;
up->port.line = 0;
up->port.type = PORT_SC16IS7XX;
up->port.dev = &client->dev;
@@ -780,7 +803,7 @@ static int sc16is7xx_probe(struct i2c_client *client,
"uart_add_one_port failed with error %d\n",
retval);
- i2c_set_clientdata(client,up);
+ i2c_set_clientdata(client, up);
/* Disable interrupts */
up->ier = 0;
@@ -790,7 +813,8 @@ static int sc16is7xx_probe(struct i2c_client *client,
NULL, sc16is7xx_ist,
IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
DRV_NAME, up) < 0) {
- dev_err(&up->client->dev, "cannot allocate irq %d\n", up->port.irq);
+ dev_err(&up->client->dev, "cannot allocate irq %d\n",
+ up->port.irq);
return -EBUSY;
}
@@ -805,10 +829,8 @@ static int sc16is7xx_remove(struct i2c_client *client)
{
struct uart_sc16is7xx_port *up = i2c_get_clientdata(client);
- if(!uart_driver_registered)
- {
+ if (!uart_driver_registered)
return 0;
- }
devm_free_irq(&client->dev, up->port.irq, up);
@@ -816,7 +838,6 @@ static int sc16is7xx_remove(struct i2c_client *client)
dev_dbg(&client->dev, "%s: removing port\n", __func__);
uart_remove_one_port(&sc16is7xx_uart_driver, &up->port);
kfree(up);
- up = NULL;
pr_debug("removing sc16is7xx driver\n");
uart_unregister_driver(&sc16is7xx_uart_driver);
@@ -827,7 +848,7 @@ static int sc16is7xx_remove(struct i2c_client *client)
}
static const struct i2c_device_id sc16is7xx_i2c_id[] = {
- { "sc16is7xx",0},
+ { "sc16is7xx", 0},
{ }
};
--
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