[PATCH v2 1/3] tty: goldfish: Refactor constants to better reflect their nature

From: Aleksandar Markovic
Date: Mon Aug 28 2017 - 07:35:05 EST


From: Aleksandar Markovic <aleksandar.markovic@xxxxxxxxxx>

Classify constants GOLDFISH_TTY_xxx into two groups: command ids and
register offsets. Apply different naming for regiter offsets (add
'REG_' after 'GOLDFISH_TTY_' in constant names). Change implementation
to use preprocessor's '#define' statements instead of 'enum'
declaration (as this is more common way of implementation in such
cases).

This makes the driver code easier to follow and hopefully prevents
future bugs.

Signed-off-by: Miodrag Dinic <miodrag.dinic@xxxxxxxxxx>
Signed-off-by: Goran Ferenc <goran.ferenc@xxxxxxxxxx>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@xxxxxxxxxx>
---
drivers/tty/goldfish.c | 52 ++++++++++++++++++++++++--------------------------
1 file changed, 25 insertions(+), 27 deletions(-)

diff --git a/drivers/tty/goldfish.c b/drivers/tty/goldfish.c
index 996bd47..011eb53 100644
--- a/drivers/tty/goldfish.c
+++ b/drivers/tty/goldfish.c
@@ -23,20 +23,18 @@
#include <linux/module.h>
#include <linux/goldfish.h>

-enum {
- GOLDFISH_TTY_PUT_CHAR = 0x00,
- GOLDFISH_TTY_BYTES_READY = 0x04,
- GOLDFISH_TTY_CMD = 0x08,
-
- GOLDFISH_TTY_DATA_PTR = 0x10,
- GOLDFISH_TTY_DATA_LEN = 0x14,
- GOLDFISH_TTY_DATA_PTR_HIGH = 0x18,
-
- GOLDFISH_TTY_CMD_INT_DISABLE = 0,
- GOLDFISH_TTY_CMD_INT_ENABLE = 1,
- GOLDFISH_TTY_CMD_WRITE_BUFFER = 2,
- GOLDFISH_TTY_CMD_READ_BUFFER = 3,
-};
+/* Goldfish tty register's offsets */
+#define GOLDFISH_TTY_REG_BYTES_READY 0x04
+#define GOLDFISH_TTY_REG_CMD 0x08
+#define GOLDFISH_TTY_REG_DATA_PTR 0x10
+#define GOLDFISH_TTY_REG_DATA_LEN 0x14
+#define GOLDFISH_TTY_REG_DATA_PTR_HIGH 0x18
+
+/* Goldfish tty commands */
+#define GOLDFISH_TTY_CMD_INT_DISABLE 0
+#define GOLDFISH_TTY_CMD_INT_ENABLE 1
+#define GOLDFISH_TTY_CMD_WRITE_BUFFER 2
+#define GOLDFISH_TTY_CMD_READ_BUFFER 3

struct goldfish_tty {
struct tty_port port;
@@ -59,10 +57,10 @@ static void goldfish_tty_do_write(int line, const char *buf, unsigned count)
struct goldfish_tty *qtty = &goldfish_ttys[line];
void __iomem *base = qtty->base;
spin_lock_irqsave(&qtty->lock, irq_flags);
- gf_write_ptr(buf, base + GOLDFISH_TTY_DATA_PTR,
- base + GOLDFISH_TTY_DATA_PTR_HIGH);
- writel(count, base + GOLDFISH_TTY_DATA_LEN);
- writel(GOLDFISH_TTY_CMD_WRITE_BUFFER, base + GOLDFISH_TTY_CMD);
+ gf_write_ptr(buf, base + GOLDFISH_TTY_REG_DATA_PTR,
+ base + GOLDFISH_TTY_REG_DATA_PTR_HIGH);
+ writel(count, base + GOLDFISH_TTY_REG_DATA_LEN);
+ writel(GOLDFISH_TTY_CMD_WRITE_BUFFER, base + GOLDFISH_TTY_REG_CMD);
spin_unlock_irqrestore(&qtty->lock, irq_flags);
}

@@ -74,16 +72,16 @@ static irqreturn_t goldfish_tty_interrupt(int irq, void *dev_id)
unsigned char *buf;
u32 count;

- count = readl(base + GOLDFISH_TTY_BYTES_READY);
+ count = readl(base + GOLDFISH_TTY_REG_BYTES_READY);
if (count == 0)
return IRQ_NONE;

count = tty_prepare_flip_string(&qtty->port, &buf, count);
spin_lock_irqsave(&qtty->lock, irq_flags);
- gf_write_ptr(buf, base + GOLDFISH_TTY_DATA_PTR,
- base + GOLDFISH_TTY_DATA_PTR_HIGH);
- writel(count, base + GOLDFISH_TTY_DATA_LEN);
- writel(GOLDFISH_TTY_CMD_READ_BUFFER, base + GOLDFISH_TTY_CMD);
+ gf_write_ptr(buf, base + GOLDFISH_TTY_REG_DATA_PTR,
+ base + GOLDFISH_TTY_REG_DATA_PTR_HIGH);
+ writel(count, base + GOLDFISH_TTY_REG_DATA_LEN);
+ writel(GOLDFISH_TTY_CMD_READ_BUFFER, base + GOLDFISH_TTY_REG_CMD);
spin_unlock_irqrestore(&qtty->lock, irq_flags);
tty_schedule_flip(&qtty->port);
return IRQ_HANDLED;
@@ -93,7 +91,7 @@ static int goldfish_tty_activate(struct tty_port *port, struct tty_struct *tty)
{
struct goldfish_tty *qtty = container_of(port, struct goldfish_tty,
port);
- writel(GOLDFISH_TTY_CMD_INT_ENABLE, qtty->base + GOLDFISH_TTY_CMD);
+ writel(GOLDFISH_TTY_CMD_INT_ENABLE, qtty->base + GOLDFISH_TTY_REG_CMD);
return 0;
}

@@ -101,7 +99,7 @@ static void goldfish_tty_shutdown(struct tty_port *port)
{
struct goldfish_tty *qtty = container_of(port, struct goldfish_tty,
port);
- writel(GOLDFISH_TTY_CMD_INT_DISABLE, qtty->base + GOLDFISH_TTY_CMD);
+ writel(GOLDFISH_TTY_CMD_INT_DISABLE, qtty->base + GOLDFISH_TTY_REG_CMD);
}

static int goldfish_tty_open(struct tty_struct *tty, struct file *filp)
@@ -136,7 +134,7 @@ static int goldfish_tty_chars_in_buffer(struct tty_struct *tty)
{
struct goldfish_tty *qtty = &goldfish_ttys[tty->index];
void __iomem *base = qtty->base;
- return readl(base + GOLDFISH_TTY_BYTES_READY);
+ return readl(base + GOLDFISH_TTY_REG_BYTES_READY);
}

static void goldfish_tty_console_write(struct console *co, const char *b,
@@ -272,7 +270,7 @@ static int goldfish_tty_probe(struct platform_device *pdev)
qtty->base = base;
qtty->irq = irq;

- writel(GOLDFISH_TTY_CMD_INT_DISABLE, base + GOLDFISH_TTY_CMD);
+ writel(GOLDFISH_TTY_CMD_INT_DISABLE, base + GOLDFISH_TTY_REG_CMD);

ret = request_irq(irq, goldfish_tty_interrupt, IRQF_SHARED,
"goldfish_tty", qtty);
--
2.7.4