Re: [PATCH v7] serial: support for 16550A serial ports on LP-8x4x
From: Andy Shevchenko <hidden>
Date: 2016-03-01 11:06:04
Also in:
linux-serial, lkml
On Tue, 2016-03-01 at 00:26 +0300, Sergei Ianovich wrote:
The patch adds support for 3 additional LP-8x4x built-in serial ports. The device can also host up to 8 extension cards with 4 serial ports on each card for a total of 35 ports. However, I don't have the hardware to test extension cards, so they are not supported, yet. Signed-off-by: Sergei Ianovich <redacted> Reviewed-by: Heikki Krogerus <heikki.krogerus-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Few more comments, mostly about style.
+static void lp8841_serial_set_termios(struct uart_port *port,
+ struct ktermios *termios, struct ktermios *old)
+{
+#ifdef BOTHER
+ unsigned int cbaud;
+#endif
+ unsigned int baud;
+ unsigned int len;Since you are writing this to the register at the end maybe - unsigned int -> u8 (write*b* — exactly one byte) - len -> value (it's not only about data length)
+ unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
+ struct lp8841_serial_data *data = port->private_data;
+
+ /* We only support CS7 and CS8 */
+ while ((termios->c_cflag & CSIZE) != CS7 &&
+ (termios->c_cflag & CSIZE) != CS8) {
+ termios->c_cflag &= ~CSIZE;
+ termios->c_cflag |= old_csize;
+ old_csize = CS8;
+ }
+
+ serial8250_do_set_termios(port, termios, old);
+
+ if ((termios->c_cflag & CSIZE) == CS7)
+ len = 9;
+ else
+ len = 10;
+
+ if (termios->c_cflag & CSTOPB)
+ len++;+ if (termios->c_cflag & PARENB) + len++; + if (!(termios->c_cflag & PARODD)) + len++; +#ifdef CMSPAR + if (termios->c_cflag & CMSPAR) + len++; +#endif
I don't know if someone likes it or not (up to you), but for me looks better to have ternary operators here: value += (termios->c_cflag & CSTOPB) ? 1 : 0; value += (termios->c_cflag & PARENB) ? 1 : 0; value += (termios->c_cflag & PARODD) ? 0 : 1; #ifdef CMSPAR value += (termios->c_cflag & CMSPAR) ? 1 : 0; #endif
+ len -= 9;
This one could be part of previous evaluation: value = (termios->c_cflag & CSIZE) == CS7 ? 0 : 1;
+ len &= 3; + len <<= 3;
Perhaps to define magic number (e.g. LP8841_DATA_LEN_SHIFT).
+
+ baud = tty_termios_baud_rate(termios);
+
+#ifdef BOTHER
+ /* We only support fixed rates */
+ cbaud = termios->c_cflag & CBAUD;
+
+ if (cbaud == BOTHER) {
+ termios->c_cflag &= ~BOTHER;
+
+ /* Don't rewrite B0 */
+ if (baud) {
+ tty_termios_encode_baud_rate(termios, baud,
baud);
+ baud = tty_termios_baud_rate(termios);
+
+ /* Set sane default speed if we get 0 */
+ if (!baud) {
+ baud = 9600;+ tty_termios_encode_baud_rate(termios , + baud, baud);
I think you can call this unconditionally together with case > 115200.
+ }
+ }
+ }
+#endif
+
+ /* We only support up to 115200 */
+ if (baud > 115200) {
+ baud = 115200;
+ tty_termios_encode_baud_rate(termios, baud, baud);
+ }Btw, can we use uart_get_baud_rate() here?
+ writeb(len, data->ios_mem); + +}
+static int lp8841_serial_probe(struct platform_device *pdev)
+{
+ struct uart_8250_port uart = {};
{0}
+ struct lp8841_serial_data *data; + struct resource *mmres, *mires; + int ret; + + mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ mires = platform_get_resource(pdev, IORESOURCE_MEM, 1);
Perhaps move it down to be closer to devm_ioremap_resource() call.
+ if (!mmres) + return -ENODEV; + + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; +
+ mires = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+ data->ios_mem = devm_ioremap_resource(&pdev->dev, mires); + if (IS_ERR(data->ios_mem)) + return PTR_ERR(data->ios_mem);
-- Andy Shevchenko [off-list ref] Intel Finland Oy -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html