linux-kernel - [PATCH 2/7] serial: sc16is7xx: remove global regmap from struct sc16is7xx

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Message-Id: <20231130191050.3165862-3-hugo@hugovil.com>
Date:   Thu, 30 Nov 2023 14:10:44 -0500
From:   Hugo Villeneuve <hugo@...ovil.com>
To:     gregkh@...uxfoundation.org, jirislaby@...nel.org,
        hvilleneuve@...onoff.com
Cc:     linux-kernel@...r.kernel.org, linux-serial@...r.kernel.org,
        hugo@...ovil.com, stable@...r.kernel.org,
        Andy Shevchenko <andy.shevchenko@...il.com>
Subject: [PATCH 2/7] serial: sc16is7xx: remove global regmap from struct sc16is7xx_port

From: Hugo Villeneuve <hvilleneuve@...onoff.com>

Remove global struct regmap so that it is more obvious that this
regmap is to be used only in the probe function.

Also add a comment to that effect in probe function.

Fixes: 3837a0379533 ("serial: sc16is7xx: improve regmap debugfs by using one regmap per port")
Cc: stable@...r.kernel.org
Suggested-by: Andy Shevchenko <andy.shevchenko@...il.com>
Signed-off-by: Hugo Villeneuve <hvilleneuve@...onoff.com>
---
 drivers/tty/serial/sc16is7xx.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 8e5baf2f6ec6..23dbf77633aa 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -334,7 +334,6 @@ struct sc16is7xx_one {
 
 struct sc16is7xx_port {
 	const struct sc16is7xx_devtype	*devtype;
-	struct regmap			*regmap;
 	struct clk			*clk;
 #ifdef CONFIG_GPIOLIB
 	struct gpio_chip		gpio;
@@ -1422,7 +1421,8 @@ static void sc16is7xx_setup_irda_ports(struct sc16is7xx_port *s)
 /*
  * Configure ports designated to operate as modem control lines.
  */
-static int sc16is7xx_setup_mctrl_ports(struct sc16is7xx_port *s)
+static int sc16is7xx_setup_mctrl_ports(struct sc16is7xx_port *s,
+				       struct regmap *regmap)
 {
 	int i;
 	int ret;
@@ -1451,7 +1451,7 @@ static int sc16is7xx_setup_mctrl_ports(struct sc16is7xx_port *s)
 
 	if (s->mctrl_mask)
 		regmap_update_bits(
-			s->regmap,
+			regmap,
 			SC16IS7XX_IOCONTROL_REG,
 			SC16IS7XX_IOCONTROL_MODEM_A_BIT |
 			SC16IS7XX_IOCONTROL_MODEM_B_BIT, s->mctrl_mask);
@@ -1483,6 +1483,10 @@ static int sc16is7xx_probe(struct device *dev,
 	 * This device does not have an identification register that would
 	 * tell us if we are really connected to the correct device.
 	 * The best we can do is to check if communication is at all possible.
+	 *
+	 * Note: regmap[0] is used in the probe function to access registers
+	 * common to all channels/ports, as it is guaranteed to be present on
+	 * all variants.
 	 */
 	ret = regmap_read(regmaps[0], SC16IS7XX_LSR_REG, &val);
 	if (ret < 0)
@@ -1518,7 +1522,6 @@ static int sc16is7xx_probe(struct device *dev,
 			return -EINVAL;
 	}
 
-	s->regmap = regmaps[0];
 	s->devtype = devtype;
 	dev_set_drvdata(dev, s);
 	mutex_init(&s->efr_lock);
@@ -1533,7 +1536,7 @@ static int sc16is7xx_probe(struct device *dev,
 	sched_set_fifo(s->kworker_task);
 
 	/* reset device, purging any pending irq / data */
-	regmap_write(s->regmap, SC16IS7XX_IOCONTROL_REG,
+	regmap_write(regmaps[0], SC16IS7XX_IOCONTROL_REG,
 		     SC16IS7XX_IOCONTROL_SRESET_BIT);
 
 	for (i = 0; i < devtype->nr_uart; ++i) {
@@ -1604,7 +1607,7 @@ static int sc16is7xx_probe(struct device *dev,
 
 	sc16is7xx_setup_irda_ports(s);
 
-	ret = sc16is7xx_setup_mctrl_ports(s);
+	ret = sc16is7xx_setup_mctrl_ports(s, regmaps[0]);
 	if (ret)
 		goto out_ports;
 
-- 
2.39.2