[PATCH 17/18] serial: max310x: reformat and improve comments

From: Hugo Villeneuve
Date: Wed Jan 17 2024 - 17:43:41 EST


From: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>

Add comments about I2C slave address structure, and reformat to
improve readability.

Also reformat some comments according to kernel coding style.

Signed-off-by: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>
---
drivers/tty/serial/max310x.c | 40 ++++++++++++++++++++++--------------
1 file changed, 25 insertions(+), 15 deletions(-)

diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c
index 6ef0155074dd..c7849b92abb0 100644
--- a/drivers/tty/serial/max310x.c
+++ b/drivers/tty/serial/max310x.c
@@ -179,7 +179,8 @@
#define MAX310X_FLOWCTRL_GPIADDR_BIT (1 << 2) /* Enables that GPIO inputs
* are used in conjunction with
* XOFF2 for definition of
- * special character */
+ * special character
+ */
#define MAX310X_FLOWCTRL_SWFLOWEN_BIT (1 << 3) /* Auto SW flow ctrl enable */
#define MAX310X_FLOWCTRL_SWFLOW0_BIT (1 << 4) /* SWFLOW bit 0 */
#define MAX310X_FLOWCTRL_SWFLOW1_BIT (1 << 5) /* SWFLOW bit 1
@@ -258,7 +259,7 @@ struct max310x_devtype {
struct {
unsigned short min;
unsigned short max;
- } slave_addr;
+ } slave_addr; /* Relevant only in I2C mode. */
int nr;
char name[9];
u8 mode1;
@@ -639,7 +640,8 @@ static void max310x_handle_rx(struct uart_port *port, unsigned int rxlen)
u8 ch, flag;

if (port->read_status_mask == MAX310X_LSR_RXOVR_BIT) {
- /* We are just reading, happily ignoring any error conditions.
+ /*
+ * We are just reading, happily ignoring any error conditions.
* Break condition, parity checking, framing errors -- they
* are all ignored. That means that we can do a batch-read.
*
@@ -648,7 +650,7 @@ static void max310x_handle_rx(struct uart_port *port, unsigned int rxlen)
* that the LSR register applies to the "current" character.
* That's also the reason why we cannot do batched reads when
* asked to check the individual statuses.
- * */
+ */

sts = max310x_port_read(port, MAX310X_LSR_IRQSTS_REG);
max310x_batch_read(port, one->rx_buf, rxlen);
@@ -752,8 +754,10 @@ static void max310x_handle_tx(struct uart_port *port)
to_send = (to_send > txlen) ? txlen : to_send;

if (until_end < to_send) {
- /* It's a circ buffer -- wrap around.
- * We could do that in one SPI transaction, but meh. */
+ /*
+ * It's a circ buffer -- wrap around.
+ * We could do that in one SPI transaction, but meh.
+ */
max310x_batch_write(port, xmit->buf + xmit->tail, until_end);
max310x_batch_write(port, xmit->buf, to_send - until_end);
} else {
@@ -842,7 +846,8 @@ static unsigned int max310x_tx_empty(struct uart_port *port)

static unsigned int max310x_get_mctrl(struct uart_port *port)
{
- /* DCD and DSR are not wired and CTS/RTS is handled automatically
+ /*
+ * DCD and DSR are not wired and CTS/RTS is handled automatically
* so just indicate DSR and CAR asserted
*/
return TIOCM_DSR | TIOCM_CAR;
@@ -934,7 +939,8 @@ static void max310x_set_termios(struct uart_port *port,
max310x_port_write(port, MAX310X_XON1_REG, termios->c_cc[VSTART]);
max310x_port_write(port, MAX310X_XOFF1_REG, termios->c_cc[VSTOP]);

- /* Disable transmitter before enabling AutoCTS or auto transmitter
+ /*
+ * Disable transmitter before enabling AutoCTS or auto transmitter
* flow control
*/
if (termios->c_cflag & CRTSCTS || termios->c_iflag & IXOFF) {
@@ -961,7 +967,8 @@ static void max310x_set_termios(struct uart_port *port,
}
max310x_port_write(port, MAX310X_FLOWCTRL_REG, flow);

- /* Enable transmitter after disabling AutoCTS and auto transmitter
+ /*
+ * Enable transmitter after disabling AutoCTS and auto transmitter
* flow control
*/
if (!(termios->c_cflag & CRTSCTS) && !(termios->c_iflag & IXOFF)) {
@@ -1052,8 +1059,11 @@ static int max310x_startup(struct uart_port *port)
MAX310X_MODE2_ECHOSUPR_BIT);
}

- /* Configure flow control levels */
- /* Flow control halt level 96, resume level 48 */
+ /*
+ * Configure flow control levels:
+ * resume: 48
+ * halt: 96
+ */
max310x_port_write(port, MAX310X_FLOWLVL_REG,
MAX310X_FLOWLVL_RES(48) | MAX310X_FLOWLVL_HALT(96));

@@ -1561,10 +1571,10 @@ static unsigned short max310x_i2c_slave_addr(unsigned short addr,
* For MAX14830 and MAX3109, the slave address depends on what the
* A0 and A1 pins are tied to.
* See Table I2C Address Map of the datasheet.
- * Based on that table, the following formulas were determined.
- * UART1 - UART0 = 0x10
- * UART2 - UART1 = 0x20 + 0x10
- * UART3 - UART2 = 0x10
+ * Based on that table, the following formulas were determined:
+ * UART1 - UART0 = 0x10
+ * UART2 - UART1 = 0x20 + 0x10
+ * UART3 - UART2 = 0x10
*/

addr -= nr * 0x10;
--
2.39.2