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authorJi-Ze Hong (Peter Hong) <hpeter@gmail.com>2019-04-30 04:22:31 +0300
committerJohan Hovold <johan@kernel.org>2019-05-03 10:19:54 +0300
commit268ddb5e9b62221beda22b8e956cf6e732538a90 (patch)
tree1e7f5a28537cdb77933ea273f261ceee7997cd1f /drivers
parent1c6b7ab2dd0763657fc7cac562976fa01772d040 (diff)
downloadlinux-268ddb5e9b62221beda22b8e956cf6e732538a90.tar.xz
USB: serial: f81232: add high baud rate support
The F81232 had 4 clocksource 1.846/18.46/14.77/24MHz and baud rates can be up to 1.5Mbits with 24MHz. F81232 Clock registers (106h) Bit1-0: Clock source selector 00: 1.846MHz. 01: 18.46MHz. 10: 24MHz. 11: 14.77MHz. Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com> Signed-off-by: Johan Hovold <johan@kernel.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/usb/serial/f81232.c105
1 files changed, 94 insertions, 11 deletions
diff --git a/drivers/usb/serial/f81232.c b/drivers/usb/serial/f81232.c
index 840694bf57c1..4f65ddd65cab 100644
--- a/drivers/usb/serial/f81232.c
+++ b/drivers/usb/serial/f81232.c
@@ -28,7 +28,8 @@ static const struct usb_device_id id_table[] = {
MODULE_DEVICE_TABLE(usb, id_table);
/* Maximum baudrate for F81232 */
-#define F81232_MAX_BAUDRATE 115200
+#define F81232_MAX_BAUDRATE 1500000
+#define F81232_DEF_BAUDRATE 9600
/* USB Control EP parameter */
#define F81232_REGISTER_REQUEST 0xa0
@@ -44,18 +45,42 @@ MODULE_DEVICE_TABLE(usb, id_table);
#define LINE_STATUS_REGISTER (0x05 + SERIAL_BASE_ADDRESS)
#define MODEM_STATUS_REGISTER (0x06 + SERIAL_BASE_ADDRESS)
+/*
+ * F81232 Clock registers (106h)
+ *
+ * Bit1-0: Clock source selector
+ * 00: 1.846MHz.
+ * 01: 18.46MHz.
+ * 10: 24MHz.
+ * 11: 14.77MHz.
+ */
+#define F81232_CLK_REGISTER 0x106
+#define F81232_CLK_1_846_MHZ 0
+#define F81232_CLK_18_46_MHZ BIT(0)
+#define F81232_CLK_24_MHZ BIT(1)
+#define F81232_CLK_14_77_MHZ (BIT(1) | BIT(0))
+#define F81232_CLK_MASK GENMASK(1, 0)
+
struct f81232_private {
struct mutex lock;
u8 modem_control;
u8 modem_status;
+ speed_t baud_base;
struct work_struct lsr_work;
struct work_struct interrupt_work;
struct usb_serial_port *port;
};
-static int calc_baud_divisor(speed_t baudrate)
+static u32 const baudrate_table[] = { 115200, 921600, 1152000, 1500000 };
+static u8 const clock_table[] = { F81232_CLK_1_846_MHZ, F81232_CLK_14_77_MHZ,
+ F81232_CLK_18_46_MHZ, F81232_CLK_24_MHZ };
+
+static int calc_baud_divisor(speed_t baudrate, speed_t clockrate)
{
- return DIV_ROUND_CLOSEST(F81232_MAX_BAUDRATE, baudrate);
+ if (!baudrate)
+ return 0;
+
+ return DIV_ROUND_CLOSEST(clockrate, baudrate);
}
static int f81232_get_register(struct usb_serial_port *port, u16 reg, u8 *val)
@@ -129,6 +154,21 @@ static int f81232_set_register(struct usb_serial_port *port, u16 reg, u8 val)
return status;
}
+static int f81232_set_mask_register(struct usb_serial_port *port, u16 reg,
+ u8 mask, u8 val)
+{
+ int status;
+ u8 tmp;
+
+ status = f81232_get_register(port, reg, &tmp);
+ if (status)
+ return status;
+
+ tmp = (tmp & ~mask) | (val & mask);
+
+ return f81232_set_register(port, reg, tmp);
+}
+
static void f81232_read_msr(struct usb_serial_port *port)
{
int status;
@@ -346,13 +386,53 @@ static void f81232_break_ctl(struct tty_struct *tty, int break_state)
*/
}
-static void f81232_set_baudrate(struct usb_serial_port *port, speed_t baudrate)
+static int f81232_find_clk(speed_t baudrate)
+{
+ int idx;
+
+ for (idx = 0; idx < ARRAY_SIZE(baudrate_table); ++idx) {
+ if (baudrate <= baudrate_table[idx] &&
+ baudrate_table[idx] % baudrate == 0)
+ return idx;
+ }
+
+ return -EINVAL;
+}
+
+static void f81232_set_baudrate(struct tty_struct *tty,
+ struct usb_serial_port *port, speed_t baudrate,
+ speed_t old_baudrate)
{
+ struct f81232_private *priv = usb_get_serial_port_data(port);
u8 lcr;
int divisor;
int status = 0;
+ int i;
+ int idx;
+ speed_t baud_list[] = { baudrate, old_baudrate, F81232_DEF_BAUDRATE };
+
+ for (i = 0; i < ARRAY_SIZE(baud_list); ++i) {
+ idx = f81232_find_clk(baud_list[i]);
+ if (idx >= 0) {
+ baudrate = baud_list[i];
+ tty_encode_baud_rate(tty, baudrate, baudrate);
+ break;
+ }
+ }
+
+ if (idx < 0)
+ return;
- divisor = calc_baud_divisor(baudrate);
+ priv->baud_base = baudrate_table[idx];
+ divisor = calc_baud_divisor(baudrate, priv->baud_base);
+
+ status = f81232_set_mask_register(port, F81232_CLK_REGISTER,
+ F81232_CLK_MASK, clock_table[idx]);
+ if (status) {
+ dev_err(&port->dev, "%s failed to set CLK_REG: %d\n",
+ __func__, status);
+ return;
+ }
status = f81232_get_register(port, LINE_CONTROL_REGISTER,
&lcr); /* get LCR */
@@ -442,6 +522,7 @@ static void f81232_set_termios(struct tty_struct *tty,
u8 new_lcr = 0;
int status = 0;
speed_t baudrate;
+ speed_t old_baud;
/* Don't change anything if nothing has changed */
if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
@@ -454,11 +535,12 @@ static void f81232_set_termios(struct tty_struct *tty,
baudrate = tty_get_baud_rate(tty);
if (baudrate > 0) {
- if (baudrate > F81232_MAX_BAUDRATE) {
- baudrate = F81232_MAX_BAUDRATE;
- tty_encode_baud_rate(tty, baudrate, baudrate);
- }
- f81232_set_baudrate(port, baudrate);
+ if (old_termios)
+ old_baud = tty_termios_baud_rate(old_termios);
+ else
+ old_baud = F81232_DEF_BAUDRATE;
+
+ f81232_set_baudrate(tty, port, baudrate, old_baud);
}
if (C_PARENB(tty)) {
@@ -595,11 +677,12 @@ static int f81232_get_serial_info(struct tty_struct *tty,
struct serial_struct *ss)
{
struct usb_serial_port *port = tty->driver_data;
+ struct f81232_private *priv = usb_get_serial_port_data(port);
ss->type = PORT_16550A;
ss->line = port->minor;
ss->port = port->port_number;
- ss->baud_base = F81232_MAX_BAUDRATE;
+ ss->baud_base = priv->baud_base;
return 0;
}