diff options
author | Ji-Ze Hong (Peter Hong) <hpeter@gmail.com> | 2018-01-11 09:47:19 +0300 |
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committer | Johan Hovold <johan@kernel.org> | 2018-01-11 13:00:25 +0300 |
commit | bb543ca287f5b14a61533f959e3f62ae58890311 (patch) | |
tree | 016d618f1cec236484443c41e73a71cd8c68a244 /drivers/usb/serial/f81534.c | |
parent | f047d35782553ab862003a58b0fcf7e1b542e4f9 (diff) | |
download | linux-bb543ca287f5b14a61533f959e3f62ae58890311.tar.xz |
USB: serial: f81534: add H/W disable port support
The F81532/534 can be disable port by manufacturer with
following H/W design.
1: Connect DCD/DSR/CTS/RI pin to ground.
2: Connect RX pin to ground.
In driver, we'll implements some detect method likes following:
1: Read MSR.
2: Turn MCR LOOP bit on, off and read LSR after delay with 60ms.
It'll contain BREAK status in LSR.
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/usb/serial/f81534.c')
-rw-r--r-- | drivers/usb/serial/f81534.c | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/drivers/usb/serial/f81534.c b/drivers/usb/serial/f81534.c index 9fa990b8766f..86edec3e8c05 100644 --- a/drivers/usb/serial/f81534.c +++ b/drivers/usb/serial/f81534.c @@ -307,6 +307,20 @@ static int f81534_set_mask_register(struct usb_serial *serial, u16 reg, return f81534_set_register(serial, reg, tmp); } +static int f81534_set_phy_port_register(struct usb_serial *serial, int phy, + u16 reg, u8 data) +{ + return f81534_set_register(serial, reg + F81534_UART_OFFSET * phy, + data); +} + +static int f81534_get_phy_port_register(struct usb_serial *serial, int phy, + u16 reg, u8 *data) +{ + return f81534_get_register(serial, reg + F81534_UART_OFFSET * phy, + data); +} + static int f81534_set_port_register(struct usb_serial_port *port, u16 reg, u8 data) { @@ -733,6 +747,70 @@ static int f81534_find_config_idx(struct usb_serial *serial, u8 *index) } /* + * The F81532/534 will not report serial port to USB serial subsystem when + * H/W DCD/DSR/CTS/RI/RX pin connected to ground. + * + * To detect RX pin status, we'll enable MCR interal loopback, disable it and + * delayed for 60ms. It connected to ground If LSR register report UART_LSR_BI. + */ +static bool f81534_check_port_hw_disabled(struct usb_serial *serial, int phy) +{ + int status; + u8 old_mcr; + u8 msr; + u8 lsr; + u8 msr_mask; + + msr_mask = UART_MSR_DCD | UART_MSR_RI | UART_MSR_DSR | UART_MSR_CTS; + + status = f81534_get_phy_port_register(serial, phy, + F81534_MODEM_STATUS_REG, &msr); + if (status) + return false; + + if ((msr & msr_mask) != msr_mask) + return false; + + status = f81534_set_phy_port_register(serial, phy, + F81534_FIFO_CONTROL_REG, UART_FCR_ENABLE_FIFO | + UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT); + if (status) + return false; + + status = f81534_get_phy_port_register(serial, phy, + F81534_MODEM_CONTROL_REG, &old_mcr); + if (status) + return false; + + status = f81534_set_phy_port_register(serial, phy, + F81534_MODEM_CONTROL_REG, UART_MCR_LOOP); + if (status) + return false; + + status = f81534_set_phy_port_register(serial, phy, + F81534_MODEM_CONTROL_REG, 0x0); + if (status) + return false; + + msleep(60); + + status = f81534_get_phy_port_register(serial, phy, + F81534_LINE_STATUS_REG, &lsr); + if (status) + return false; + + status = f81534_set_phy_port_register(serial, phy, + F81534_MODEM_CONTROL_REG, old_mcr); + if (status) + return false; + + if ((lsr & UART_LSR_BI) == UART_LSR_BI) + return true; + + return false; +} + +/* * We had 2 generation of F81532/534 IC. All has an internal storage. * * 1st is pure USB-to-TTL RS232 IC and designed for 4 ports only, no any @@ -823,6 +901,9 @@ static int f81534_calc_num_ports(struct usb_serial *serial, /* New style, find all possible ports */ for (i = 0; i < F81534_NUM_PORT; ++i) { + if (f81534_check_port_hw_disabled(serial, i)) + serial_priv->conf_data[i] |= F81534_PORT_UNAVAILABLE; + if (serial_priv->conf_data[i] & F81534_PORT_UNAVAILABLE) continue; |