[PATCH 3.16 197/370] USB: serial: ch341: add register and USB request definitions

Ben Hutchings
2017-03-10T13:57:37Z

From: Aidan Thornton <makosoft@gmail.com>

commit 6fde8d29b0424f292a4ec5dbce01458ad759a41f upstream.

No functional changes, this just gives names to some registers and USB
requests based on Grigori Goronzy's work and WinChipTech's Linux driver
(which reassuringly agree), then uses them in place of magic numbers.
This also renames the misnamed BREAK2 register (actually UART config)

Signed-off-by: Aidan Thornton <makosoft@gmail.com>
Reviewed-by: Grigori Goronzy <greg@chown.ath.cx>
Signed-off-by: Johan Hovold <johan@kernel.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/usb/serial/ch341.c | 51 +++++++++++++++++++++++++++++-----------------
1 file changed, 32 insertions(+), 19 deletions(-)

--- a/drivers/usb/serial/ch341.c
+++ b/drivers/usb/serial/ch341.c
@@ -61,13 +61,26 @@
* the Net/FreeBSD uchcom.c driver by Takanori Watanabe. Domo arigato.
*/

+#define CH341_REQ_READ_VERSION 0x5F
#define CH341_REQ_WRITE_REG 0x9A
#define CH341_REQ_READ_REG 0x95
-#define CH341_REG_BREAK1 0x05
-#define CH341_REG_BREAK2 0x18
-#define CH341_NBREAK_BITS_REG1 0x01
-#define CH341_NBREAK_BITS_REG2 0x40
+#define CH341_REQ_SERIAL_INIT 0xA1
+#define CH341_REQ_MODEM_CTRL 0xA4

+#define CH341_REG_BREAK 0x05
+#define CH341_REG_LCR 0x18
+#define CH341_NBREAK_BITS 0x01
+
+#define CH341_LCR_ENABLE_RX 0x80
+#define CH341_LCR_ENABLE_TX 0x40
+#define CH341_LCR_MARK_SPACE 0x20
+#define CH341_LCR_PAR_EVEN 0x10
+#define CH341_LCR_ENABLE_PAR 0x08
+#define CH341_LCR_STOP_BITS_2 0x04
+#define CH341_LCR_CS8 0x03
+#define CH341_LCR_CS7 0x02
+#define CH341_LCR_CS6 0x01
+#define CH341_LCR_CS5 0x00

static const struct usb_device_id id_table[] = {
{ USB_DEVICE(0x4348, 0x5523) },
@@ -144,16 +157,16 @@ static int ch341_set_baudrate(struct usb
a = (factor & 0xff00) | divisor;
b = factor & 0xff;

- r = ch341_control_out(dev, 0x9a, 0x1312, a);
+ r = ch341_control_out(dev, CH341_REQ_WRITE_REG, 0x1312, a);
if (!r)
- r = ch341_control_out(dev, 0x9a, 0x0f2c, b);
+ r = ch341_control_out(dev, CH341_REQ_WRITE_REG, 0x0f2c, b);

return r;
}

static int ch341_set_handshake(struct usb_device *dev, u8 control)
{
- return ch341_control_out(dev, 0xa4, ~control, 0);
+ return ch341_control_out(dev, CH341_REQ_MODEM_CTRL, ~control, 0);
}

static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv)
@@ -167,7 +180,7 @@ static int ch341_get_status(struct usb_d
if (!buffer)
return -ENOMEM;

- r = ch341_control_in(dev, 0x95, 0x0706, 0, buffer, size);
+ r = ch341_control_in(dev, CH341_REQ_READ_REG, 0x0706, 0, buffer, size);
if (r < 0)
goto out;

@@ -197,11 +210,11 @@ static int ch341_configure(struct usb_de
return -ENOMEM;

/* expect two bytes 0x27 0x00 */
- r = ch341_control_in(dev, 0x5f, 0, 0, buffer, size);
+ r = ch341_control_in(dev, CH341_REQ_READ_VERSION, 0, 0, buffer, size);
if (r < 0)
goto out;

- r = ch341_control_out(dev, 0xa1, 0, 0);
+ r = ch341_control_out(dev, CH341_REQ_SERIAL_INIT, 0, 0);
if (r < 0)
goto out;

@@ -210,11 +223,11 @@ static int ch341_configure(struct usb_de
goto out;

/* expect two bytes 0x56 0x00 */
- r = ch341_control_in(dev, 0x95, 0x2518, 0, buffer, size);
+ r = ch341_control_in(dev, CH341_REQ_READ_REG, 0x2518, 0, buffer, size);
if (r < 0)
goto out;

- r = ch341_control_out(dev, 0x9a, 0x2518, 0x0050);
+ r = ch341_control_out(dev, CH341_REQ_WRITE_REG, 0x2518, 0x0050);
if (r < 0)
goto out;

@@ -223,7 +236,7 @@ static int ch341_configure(struct usb_de
if (r < 0)
goto out;

- r = ch341_control_out(dev, 0xa1, 0x501f, 0xd90a);
+ r = ch341_control_out(dev, CH341_REQ_SERIAL_INIT, 0x501f, 0xd90a);
if (r < 0)
goto out;

@@ -370,7 +383,7 @@ static void ch341_set_termios(struct tty
static void ch341_break_ctl(struct tty_struct *tty, int break_state)
{
const uint16_t ch341_break_reg =
- CH341_REG_BREAK1 | ((uint16_t) CH341_REG_BREAK2 << 8);
+ ((uint16_t) CH341_REG_LCR << 8) | CH341_REG_BREAK;
struct usb_serial_port *port = tty->driver_data;
int r;
uint16_t reg_contents;
@@ -391,12 +404,12 @@ static void ch341_break_ctl(struct tty_s
__func__, break_reg[0], break_reg[1]);
if (break_state != 0) {
dev_dbg(&port->dev, "%s - Enter break state requested\n", __func__);
- break_reg[0] &= ~CH341_NBREAK_BITS_REG1;
- break_reg[1] &= ~CH341_NBREAK_BITS_REG2;
+ break_reg[0] &= ~CH341_NBREAK_BITS;
+ break_reg[1] &= ~CH341_LCR_ENABLE_TX;
} else {
dev_dbg(&port->dev, "%s - Leave break state requested\n", __func__);
- break_reg[0] |= CH341_NBREAK_BITS_REG1;
- break_reg[1] |= CH341_NBREAK_BITS_REG2;
+ break_reg[0] |= CH341_NBREAK_BITS;
+ break_reg[1] |= CH341_LCR_ENABLE_TX;
}
dev_dbg(&port->dev, "%s - New ch341 break register contents - reg1: %x, reg2: %x\n",
__func__, break_reg[0], break_reg[1]);