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path: root/drivers/tty/serial/max310x.c
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Diffstat (limited to 'drivers/tty/serial/max310x.c')
-rw-r--r--drivers/tty/serial/max310x.c53
1 files changed, 43 insertions, 10 deletions
diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c
index f3a99daebdaa..10bf6d75bf9e 100644
--- a/drivers/tty/serial/max310x.c
+++ b/drivers/tty/serial/max310x.c
@@ -237,6 +237,14 @@
#define MAX310x_REV_MASK (0xf8)
#define MAX310X_WRITE_BIT 0x80
+/* Port startup definitions */
+#define MAX310X_PORT_STARTUP_WAIT_RETRIES 20 /* Number of retries */
+#define MAX310X_PORT_STARTUP_WAIT_DELAY_MS 10 /* Delay between retries */
+
+/* Crystal-related definitions */
+#define MAX310X_XTAL_WAIT_RETRIES 20 /* Number of retries */
+#define MAX310X_XTAL_WAIT_DELAY_MS 10 /* Delay between retries */
+
/* MAX3107 specific */
#define MAX3107_REV_ID (0xa0)
@@ -583,7 +591,7 @@ static int max310x_update_best_err(unsigned long f, long *besterr)
return 1;
}
-static u32 max310x_set_ref_clk(struct device *dev, struct max310x_port *s,
+static s32 max310x_set_ref_clk(struct device *dev, struct max310x_port *s,
unsigned long freq, bool xtal)
{
unsigned int div, clksrc, pllcfg = 0;
@@ -641,12 +649,20 @@ static u32 max310x_set_ref_clk(struct device *dev, struct max310x_port *s,
/* Wait for crystal */
if (xtal) {
- unsigned int val;
- msleep(10);
- regmap_read(s->regmap, MAX310X_STS_IRQSTS_REG, &val);
- if (!(val & MAX310X_STS_CLKREADY_BIT)) {
- dev_warn(dev, "clock is not stable yet\n");
- }
+ bool stable = false;
+ unsigned int try = 0, val = 0;
+
+ do {
+ msleep(MAX310X_XTAL_WAIT_DELAY_MS);
+ regmap_read(s->regmap, MAX310X_STS_IRQSTS_REG, &val);
+
+ if (val & MAX310X_STS_CLKREADY_BIT)
+ stable = true;
+ } while (!stable && (++try < MAX310X_XTAL_WAIT_RETRIES));
+
+ if (!stable)
+ return dev_err_probe(dev, -EAGAIN,
+ "clock is not stable\n");
}
return bestfreq;
@@ -1271,7 +1287,7 @@ static int max310x_probe(struct device *dev, const struct max310x_devtype *devty
{
int i, ret, fmin, fmax, freq;
struct max310x_port *s;
- u32 uartclk = 0;
+ s32 uartclk = 0;
bool xtal;
for (i = 0; i < devtype->nr; i++)
@@ -1334,6 +1350,9 @@ static int max310x_probe(struct device *dev, const struct max310x_devtype *devty
goto out_clk;
for (i = 0; i < devtype->nr; i++) {
+ bool started = false;
+ unsigned int try = 0, val = 0;
+
/* Reset port */
regmap_write(regmaps[i], MAX310X_MODE2_REG,
MAX310X_MODE2_RST_BIT);
@@ -1342,13 +1361,27 @@ static int max310x_probe(struct device *dev, const struct max310x_devtype *devty
/* Wait for port startup */
do {
- regmap_read(regmaps[i], MAX310X_BRGDIVLSB_REG, &ret);
- } while (ret != 0x01);
+ msleep(MAX310X_PORT_STARTUP_WAIT_DELAY_MS);
+ regmap_read(regmaps[i], MAX310X_BRGDIVLSB_REG, &val);
+
+ if (val == 0x01)
+ started = true;
+ } while (!started && (++try < MAX310X_PORT_STARTUP_WAIT_RETRIES));
+
+ if (!started) {
+ ret = dev_err_probe(dev, -EAGAIN, "port reset failed\n");
+ goto out_uart;
+ }
regmap_write(regmaps[i], MAX310X_MODE1_REG, devtype->mode1);
}
uartclk = max310x_set_ref_clk(dev, s, freq, xtal);
+ if (uartclk < 0) {
+ ret = uartclk;
+ goto out_uart;
+ }
+
dev_dbg(dev, "Reference clock set to %i Hz\n", uartclk);
for (i = 0; i < devtype->nr; i++) {