i2c: lpi2c: use readl_poll_timeout() for register polling

Replaces polling loops with the readl_poll_timeout() helper macro.

Signed-off-by: Emanuele Ghidoli <emanuele.ghidoli@toradex.com>
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Reviewed-by: Carlos Song <carlos.song@nxp.com>
Tested-by: Primoz Fiser <primoz.fiser@norik.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20250718133429.67219-2-francesco@dolcini.it

diff --git a/drivers/i2c/busses/i2c-imx-lpi2c.c b/drivers/i2c/busses/i2c-imx-lpi2c.c
index 717b617dbc2cbc0edc142807fd75dbf02e39231f..1a802a51853d13e37867d8caecd437b1d92476cc 100644 (file)
--- a/drivers/i2c/busses/i2c-imx-lpi2c.c
+++ b/drivers/i2c/busses/i2c-imx-lpi2c.c
@@ -16,6 +16,7 @@
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
@@ -187,6 +188,10 @@ struct lpi2c_imx_struct {
        struct i2c_client       *target;
 };
 
+#define lpi2c_imx_read_msr_poll_timeout(val, cond)                            \
+                 readl_poll_timeout(lpi2c_imx->base + LPI2C_MSR, val, cond,  \
+                                    0, 500000)
+
 static void lpi2c_imx_intctrl(struct lpi2c_imx_struct *lpi2c_imx,
                              unsigned int enable)
 {
@@ -195,33 +200,34 @@ static void lpi2c_imx_intctrl(struct lpi2c_imx_struct *lpi2c_imx,
 
 static int lpi2c_imx_bus_busy(struct lpi2c_imx_struct *lpi2c_imx)
 {
-       unsigned long orig_jiffies = jiffies;
        unsigned int temp;
+       int err;
 
-       while (1) {
-               temp = readl(lpi2c_imx->base + LPI2C_MSR);
-
-               /* check for arbitration lost, clear if set */
-               if (temp & MSR_ALF) {
-                       writel(temp, lpi2c_imx->base + LPI2C_MSR);
-                       return -EAGAIN;
-               }
+       err = lpi2c_imx_read_msr_poll_timeout(temp,
+                                             temp & (MSR_ALF | MSR_BBF | MSR_MBF));
 
-               if (temp & (MSR_BBF | MSR_MBF))
-                       break;
+       /* check for arbitration lost, clear if set */
+       if (temp & MSR_ALF) {
+               writel(temp, lpi2c_imx->base + LPI2C_MSR);
+               return -EAGAIN;
+       }
 
-               if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
-                       dev_dbg(&lpi2c_imx->adapter.dev, "bus not work\n");
-                       if (lpi2c_imx->adapter.bus_recovery_info)
-                               i2c_recover_bus(&lpi2c_imx->adapter);
-                       return -ETIMEDOUT;
-               }
-               schedule();
+       /* check for bus not busy */
+       if (err) {
+               dev_dbg(&lpi2c_imx->adapter.dev, "bus not work\n");
+               if (lpi2c_imx->adapter.bus_recovery_info)
+                       i2c_recover_bus(&lpi2c_imx->adapter);
+               return -ETIMEDOUT;
        }
 
        return 0;
 }
 
+static u32 lpi2c_imx_txfifo_cnt(struct lpi2c_imx_struct *lpi2c_imx)
+{
+       return readl(lpi2c_imx->base + LPI2C_MFSR) & 0xff;
+}
+
 static void lpi2c_imx_set_mode(struct lpi2c_imx_struct *lpi2c_imx)
 {
        unsigned int bitrate = lpi2c_imx->bitrate;
@@ -259,25 +265,18 @@ static int lpi2c_imx_start(struct lpi2c_imx_struct *lpi2c_imx,
 
 static void lpi2c_imx_stop(struct lpi2c_imx_struct *lpi2c_imx)
 {
-       unsigned long orig_jiffies = jiffies;
        unsigned int temp;
+       int err;
 
        writel(GEN_STOP << 8, lpi2c_imx->base + LPI2C_MTDR);
 
-       do {
-               temp = readl(lpi2c_imx->base + LPI2C_MSR);
-               if (temp & MSR_SDF)
-                       break;
+       err = lpi2c_imx_read_msr_poll_timeout(temp, temp & MSR_SDF);
 
-               if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
-                       dev_dbg(&lpi2c_imx->adapter.dev, "stop timeout\n");
-                       if (lpi2c_imx->adapter.bus_recovery_info)
-                               i2c_recover_bus(&lpi2c_imx->adapter);
-                       break;
-               }
-               schedule();
-
-       } while (1);
+       if (err) {
+               dev_dbg(&lpi2c_imx->adapter.dev, "stop timeout\n");
+               if (lpi2c_imx->adapter.bus_recovery_info)
+                       i2c_recover_bus(&lpi2c_imx->adapter);
+       }
 }
 
 /* CLKLO = I2C_CLK_RATIO * CLKHI, SETHOLD = CLKHI, DATAVD = CLKHI/2 */
@@ -393,26 +392,23 @@ static int lpi2c_imx_pio_msg_complete(struct lpi2c_imx_struct *lpi2c_imx)
 
 static int lpi2c_imx_txfifo_empty(struct lpi2c_imx_struct *lpi2c_imx)
 {
-       unsigned long orig_jiffies = jiffies;
-       u32 txcnt;
-
-       do {
-               txcnt = readl(lpi2c_imx->base + LPI2C_MFSR) & 0xff;
+       unsigned int temp;
+       int err;
 
-               if (readl(lpi2c_imx->base + LPI2C_MSR) & MSR_NDF) {
-                       dev_dbg(&lpi2c_imx->adapter.dev, "NDF detected\n");
-                       return -EIO;
-               }
+       err = lpi2c_imx_read_msr_poll_timeout(temp,
+                                             (temp & MSR_NDF) || !lpi2c_imx_txfifo_cnt(lpi2c_imx));
 
-               if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
-                       dev_dbg(&lpi2c_imx->adapter.dev, "txfifo empty timeout\n");
-                       if (lpi2c_imx->adapter.bus_recovery_info)
-                               i2c_recover_bus(&lpi2c_imx->adapter);
-                       return -ETIMEDOUT;
-               }
-               schedule();
+       if (temp & MSR_NDF) {
+               dev_dbg(&lpi2c_imx->adapter.dev, "NDF detected\n");
+               return -EIO;
+       }
 
-       } while (txcnt);
+       if (err) {
+               dev_dbg(&lpi2c_imx->adapter.dev, "txfifo empty timeout\n");
+               if (lpi2c_imx->adapter.bus_recovery_info)
+                       i2c_recover_bus(&lpi2c_imx->adapter);
+               return -ETIMEDOUT;
+       }
 
        return 0;
 }