Hi Andy,


2015-05-25 18:14 GMT+09:00 Shevchenko, Andriy [off-list ref]:

On Mon, 2015-05-25 at 12:44 +0900, Masahiro Yamada wrote:

quoted

Add the driver for on-chip UART used on UniPhier SoCs.

This hardware is similar to 8250, but the register mapping is
slightly different:
  - The offset to FCR, MCR is different.
  - The divisor latch access bit does not exist.  Instead, the
    divisor latch register is available at offset 9.

This driver overrides serial_{in,out}, dl_{read,write} callbacks,
but wants to borrow most of code from 8250_core.c.

Do not send series too often, let people to review what you did.

More comments below.

quoted

+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+#include "8250.h"
+
+/* Most (but not all) of UniPhier UART devices have 64-depth FIFO. */
+#define UNIPHIER_UART_DEFAULT_FIFO_SIZE      64
+
+#define UNIPHIER_UART_CHAR_FCR       3       /* Character / FIFO Control Register */
+#define UNIPHIER_UART_LCR_MCR        4       /* Line/Modem Control Register */
+#define   UNIPHIER_UART_LCR_SHIFT    8

Indentation problem, needs to be fixed.

How should it be fixed?

Could you explain it more detailed, please?

quoted

+#define UNIPHIER_UART_DLR    9       /* Divisor Latch Register */
+
+struct uniphier8250_priv {
+     int line;
+     struct clk *clk;
+     spinlock_t atomic_write_lock;
+};
+
+/*
+ * The register map is slightly different from that of 8250.
+ * IO callbacks must be overridden for correct access to FCR, LCR, and MCR.
+ */
+static unsigned int uniphier_serial_in(struct uart_port *p, int offset)
+{
+     int valshift = 0;

Perhaps unsigned int?

OK, I will fix it (after waiting for some more comments).

quoted

+     bool normal = false;
+
+     switch (offset) {
+     case UART_FCR:
+             offset = UNIPHIER_UART_CHAR_FCR;
+             break;
+     case UART_LCR:
+             valshift = UNIPHIER_UART_LCR_SHIFT;
+             /* Divisor latch access bit does not exist. */
+             value &= ~(UART_LCR_DLAB << valshift);
+             /* fall through */
+     case UART_MCR:
+             offset = UNIPHIER_UART_LCR_MCR;
+             break;
+     default:
+             normal = true;
+             break;
+     }
+
+     offset <<= p->regshift;
+
+     if (normal) {
+             writel(value, p->membase + offset);

Perhaps put this in place where normal == true and use return instead of
break?

In that case, I do not know where I should put
   offset <<= p->regshift
, which I want to run for all the cases.




-- 
Best Regards
Masahiro Yamada