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Message-Id: <1454865276-22215-1-git-send-email-konstantin.shkolnyy@gmail.com>
Date: Sun, 7 Feb 2016 11:14:36 -0600
From: Konstantin Shkolnyy <konstantin.shkolnyy@...il.com>
To: johan@...nel.org
Cc: linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org,
Konstantin Shkolnyy <konstantin.shkolnyy@...il.com>
Subject: [PATCH v4 2/3] USB: serial: cp210x: New 8-bit and 32-bit register access functions.
cp210x_get_config and cp210x_set_config are cumbersome to use. This change
introduces new register access functions for 8 and 32-bit values, instead
of the above functions.
Signed-off-by: Konstantin Shkolnyy <konstantin.shkolnyy@...il.com>
---
change in v4: Instead of adding all new functions a one separate patch, added
them with patches that actually start using them. Also amended the cp210x_open
change as directed by Johan Hovold.
change in v3: Presented new function addition as a separate patch #1,
to simplify code review.
drivers/usb/serial/cp210x.c | 92 ++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 86 insertions(+), 6 deletions(-)
diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index bea6ce7..1dbad3c 100644
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -469,6 +469,29 @@ static int cp210x_read_reg_block(struct usb_serial_port *port, u8 req,
}
/*
+ * Reads any 32-bit CP210X_ register identified by req.
+ */
+static int cp210x_read_u32_reg(struct usb_serial_port *port, u8 req, u32 *val)
+{
+ __le32 le32_val;
+ int err;
+
+ err = cp210x_read_reg_block(port, req, &le32_val, sizeof(le32_val));
+ if (err) {
+ /*
+ * FIXME Some callers don't bother to check for error,
+ * at least give them consistent junk until they are fixed
+ */
+ *val = 0;
+ return err;
+ }
+
+ *val = le32_to_cpu(le32_val);
+
+ return 0;
+}
+
+/*
* Reads any 16-bit CP210X_ register identified by req.
*/
static int cp210x_read_u16_reg(struct usb_serial_port *port, u8 req, u16 *val)
@@ -481,10 +504,19 @@ static int cp210x_read_u16_reg(struct usb_serial_port *port, u8 req, u16 *val)
return err;
*val = le16_to_cpu(le16_val);
+
return 0;
}
/*
+ * Reads any 8-bit CP210X_ register identified by req.
+ */
+static int cp210x_read_u8_reg(struct usb_serial_port *port, u8 req, u8 *val)
+{
+ return cp210x_read_reg_block(port, req, val, sizeof(*val));
+}
+
+/*
* Writes any 16-bit CP210X_ register (req) whose value is passed
* entirely in the wValue field of the USB request.
*/
@@ -507,6 +539,55 @@ static int cp210x_write_u16_reg(struct usb_serial_port *port, u8 req, u16 val)
}
/*
+ * Writes a variable-sized block of CP210X_ registers, identified by req.
+ * Data in buf must be in native USB byte order.
+ */
+static int cp210x_write_reg_block(struct usb_serial_port *port, u8 req,
+ void *buf, int bufsize)
+{
+ struct usb_serial *serial = port->serial;
+ struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
+ void *dmabuf;
+ int result;
+
+ dmabuf = kmalloc(bufsize, GFP_KERNEL);
+ if (!dmabuf)
+ return -ENOMEM;
+
+ memcpy(dmabuf, buf, bufsize);
+
+ result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+ req, REQTYPE_HOST_TO_INTERFACE, 0,
+ port_priv->bInterfaceNumber, dmabuf, bufsize,
+ USB_CTRL_SET_TIMEOUT);
+
+ kfree(dmabuf);
+
+ if (result == bufsize) {
+ result = 0;
+ } else {
+ dev_err(&port->dev, "failed set req 0x%x size %d status: %d\n",
+ req, bufsize, result);
+ if (result >= 0)
+ result = -EPROTO;
+ }
+
+ return result;
+}
+
+/*
+ * Writes any 32-bit CP210X_ register identified by req.
+ */
+static int cp210x_write_u32_reg(struct usb_serial_port *port, u8 req, u32 val)
+{
+ __le32 le32_val;
+
+ le32_val = cpu_to_le32(val);
+
+ return cp210x_write_reg_block(port, req, &le32_val, sizeof(le32_val));
+}
+
+/*
* Detect CP2108 GET_LINE_CTL bug and activate workaround.
* Write a known good value 0x800, read it back.
* If it comes back swapped the bug is detected.
@@ -708,10 +789,10 @@ static void cp210x_get_termios_port(struct usb_serial_port *port,
{
struct device *dev = &port->dev;
unsigned int cflag, modem_ctl[4];
- unsigned int baud;
+ u32 baud;
u16 bits;
- cp210x_get_config(port, CP210X_GET_BAUDRATE, &baud, 4);
+ cp210x_read_u32_reg(port, CP210X_GET_BAUDRATE, &baud);
dev_dbg(dev, "%s - baud rate = %d\n", __func__, baud);
*baudp = baud;
@@ -858,8 +939,7 @@ static void cp210x_change_speed(struct tty_struct *tty,
baud = cp210x_quantise_baudrate(baud);
dev_dbg(&port->dev, "%s - setting baud rate to %u\n", __func__, baud);
- if (cp210x_set_config(port, CP210X_SET_BAUDRATE, &baud,
- sizeof(baud))) {
+ if (cp210x_write_u32_reg(port, CP210X_SET_BAUDRATE, baud)) {
dev_warn(&port->dev, "failed to set baud rate to %u\n", baud);
if (old_termios)
baud = old_termios->c_ospeed;
@@ -1030,10 +1110,10 @@ static void cp210x_dtr_rts(struct usb_serial_port *p, int on)
static int cp210x_tiocmget(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
- unsigned int control;
+ u8 control;
int result;
- cp210x_get_config(port, CP210X_GET_MDMSTS, &control, 1);
+ cp210x_read_u8_reg(port, CP210X_GET_MDMSTS, &control);
result = ((control & CONTROL_DTR) ? TIOCM_DTR : 0)
|((control & CONTROL_RTS) ? TIOCM_RTS : 0)
--
1.8.4.5
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