serial: max310x: use regmap_read_poll_timeout() for busy wait

Simplify busy wait stages by using regmap_read_poll_timeout().

Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://patch.msgid.link/20260417-max310x-2-v1-6-b424e105ecac@dimonoff.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c
index 1cd7632831a2826ddd42127b1cde2a10dfa412f0..7ab5e4bd87ee6c87dd211bc52a3a4eb169a2b202 100644 (file)
--- a/drivers/tty/serial/max310x.c
+++ b/drivers/tty/serial/max310x.c
@@ -241,12 +241,12 @@
 #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 */
+#define MAX310X_PORT_STARTUP_SLEEP_US  10000  /* Delay between retries */
+#define MAX310X_PORT_STARTUP_TIMEOUT_US        (20 * MAX310X_PORT_STARTUP_SLEEP_US) /* Total timeout */
 
 /* Crystal-related definitions */
-#define MAX310X_XTAL_WAIT_RETRIES      20 /* Number of retries */
-#define MAX310X_XTAL_WAIT_DELAY_MS     10 /* Delay between retries */
+#define MAX310X_XTAL_SLEEP_US          10000  /* Delay between retries */
+#define MAX310X_XTAL_TIMEOUT_US                (20 * MAX310X_XTAL_SLEEP_US) /* Total timeout */
 
 /* MAX3107 specific */
 #define MAX3107_REV_ID                 (0xa0)
@@ -587,7 +587,7 @@ static u8 max310x_pll_mult_to_id(u8 pll_mult)
 static int max310x_set_ref_clk(struct device *dev, struct max310x_port *s,
                               unsigned int freq, unsigned int *fref, bool xtal)
 {
-       unsigned int div, fdiv, clksrc;
+       unsigned int div, fdiv, clksrc, val;
        struct max310x_clk_config_t cfg;
 
        cfg.err = UINT_MAX;
@@ -629,18 +629,13 @@ static int max310x_set_ref_clk(struct device *dev, struct max310x_port *s,
 
        /* Wait for crystal */
        if (xtal) {
-               bool stable = false;
-               unsigned int try = 0, val = 0;
+               int ret;
 
-               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)
+               ret = regmap_read_poll_timeout(s->regmap, MAX310X_STS_IRQSTS_REG,
+                                              val, val & MAX310X_STS_CLKREADY_BIT,
+                                              MAX310X_XTAL_SLEEP_US,
+                                              MAX310X_XTAL_TIMEOUT_US);
+               if (ret)
                        return dev_err_probe(dev, -EAGAIN,
                                             "clock is not stable\n");
        }
@@ -1346,8 +1341,7 @@ 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;
+               unsigned int val;
 
                /* Reset port */
                regmap_write(regmaps[i], MAX310X_MODE2_REG,
@@ -1356,15 +1350,11 @@ static int max310x_probe(struct device *dev, const struct max310x_devtype *devty
                regmap_write(regmaps[i], MAX310X_MODE2_REG, 0);
 
                /* Wait for port startup */
-               do {
-                       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 = regmap_read_poll_timeout(regmaps[i], MAX310X_BRGDIVLSB_REG,
+                                              val, val == 0x01,
+                                              MAX310X_PORT_STARTUP_SLEEP_US,
+                                              MAX310X_PORT_STARTUP_TIMEOUT_US);
+               if (ret) {
                        ret = dev_err_probe(dev, -EAGAIN, "port reset failed\n");
                        goto out_uart;
                }