Patch "serial: max310x: use regmap methods for SPI batch operations" has been added to the 5.4-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    serial: max310x: use regmap methods for SPI batch operations

to the 5.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     serial-max310x-use-regmap-methods-for-spi-batch-oper.patch
and it can be found in the queue-5.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 169b9e3eb17685a3681218505fb91fac050bef77
Author: Cosmin Tanislav <cosmin.tanislav@xxxxxxxxxx>
Date:   Sun Jun 5 17:46:56 2022 +0300

    serial: max310x: use regmap methods for SPI batch operations
    
    [ Upstream commit 285e76fc049c4d32c772eea9460a7ef28a193802 ]
    
    The SPI batch read/write operations can be implemented as simple
    regmap raw read and write, which will also try to do a gather
    write just as it is done here.
    
    Use the regmap raw read and write methods.
    
    Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
    Signed-off-by: Cosmin Tanislav <cosmin.tanislav@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/20220605144659.4169853-2-demonsingur@xxxxxxxxx
    Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
    Stable-dep-of: b35f8dbbce81 ("serial: max310x: prevent infinite while() loop in port startup")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c
index 8d42c537ee5ea..c0fa4ad104774 100644
--- a/drivers/tty/serial/max310x.c
+++ b/drivers/tty/serial/max310x.c
@@ -263,8 +263,6 @@ struct max310x_one {
 	struct work_struct	md_work;
 	struct work_struct	rs_work;
 
-	u8 wr_header;
-	u8 rd_header;
 	u8 rx_buf[MAX310X_FIFO_SIZE];
 };
 #define to_max310x_port(_port) \
@@ -635,32 +633,18 @@ static s32 max310x_set_ref_clk(struct device *dev, struct max310x_port *s,
 
 static void max310x_batch_write(struct uart_port *port, u8 *txbuf, unsigned int len)
 {
-	struct max310x_one *one = to_max310x_port(port);
-	struct spi_transfer xfer[] = {
-		{
-			.tx_buf = &one->wr_header,
-			.len = sizeof(one->wr_header),
-		}, {
-			.tx_buf = txbuf,
-			.len = len,
-		}
-	};
-	spi_sync_transfer(to_spi_device(port->dev), xfer, ARRAY_SIZE(xfer));
+	struct max310x_port *s = dev_get_drvdata(port->dev);
+	u8 reg = port->iobase + MAX310X_THR_REG;
+
+	regmap_raw_write(s->regmap, reg, txbuf, len);
 }
 
 static void max310x_batch_read(struct uart_port *port, u8 *rxbuf, unsigned int len)
 {
-	struct max310x_one *one = to_max310x_port(port);
-	struct spi_transfer xfer[] = {
-		{
-			.tx_buf = &one->rd_header,
-			.len = sizeof(one->rd_header),
-		}, {
-			.rx_buf = rxbuf,
-			.len = len,
-		}
-	};
-	spi_sync_transfer(to_spi_device(port->dev), xfer, ARRAY_SIZE(xfer));
+	struct max310x_port *s = dev_get_drvdata(port->dev);
+	u8 reg = port->iobase + MAX310X_RHR_REG;
+
+	regmap_raw_read(s->regmap, reg, rxbuf, len);
 }
 
 static void max310x_handle_rx(struct uart_port *port, unsigned int rxlen)
@@ -1390,10 +1374,6 @@ static int max310x_probe(struct device *dev, const struct max310x_devtype *devty
 		INIT_WORK(&s->p[i].md_work, max310x_md_proc);
 		/* Initialize queue for changing RS485 mode */
 		INIT_WORK(&s->p[i].rs_work, max310x_rs_proc);
-		/* Initialize SPI-transfer buffers */
-		s->p[i].wr_header = (s->p[i].port.iobase + MAX310X_THR_REG) |
-				    MAX310X_WRITE_BIT;
-		s->p[i].rd_header = (s->p[i].port.iobase + MAX310X_RHR_REG);
 
 		/* Register port */
 		ret = uart_add_one_port(&max310x_uart, &s->p[i].port);