diff options
Diffstat (limited to 'drivers/tty/serial/8250/8250_rsa.c')
| -rw-r--r-- | drivers/tty/serial/8250/8250_rsa.c | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250/8250_rsa.c b/drivers/tty/serial/8250/8250_rsa.c new file mode 100644 index 000000000000..4c8b9671bd41 --- /dev/null +++ b/drivers/tty/serial/8250/8250_rsa.c @@ -0,0 +1,132 @@ +// SPDX-License-Identifier: GPL-2.0+ + +#include <linux/errno.h> +#include <linux/ioport.h> +#include <linux/module.h> +#include <linux/moduleparam.h> + +#include <linux/serial.h> +#include <linux/serial_8250.h> + +#include "8250.h" + +#define PORT_RSA_MAX 4 +static unsigned long probe_rsa[PORT_RSA_MAX]; +static unsigned int probe_rsa_count; + +static int rsa8250_request_resource(struct uart_8250_port *up) +{ + struct uart_port *port = &up->port; + unsigned long start = UART_RSA_BASE << port->regshift; + unsigned int size = 8 << port->regshift; + + switch (port->iotype) { + case UPIO_HUB6: + case UPIO_PORT: + start += port->iobase; + if (!request_region(start, size, "serial-rsa")) + return -EBUSY; + return 0; + default: + return -EINVAL; + } +} + +static void rsa8250_release_resource(struct uart_8250_port *up) +{ + struct uart_port *port = &up->port; + unsigned long offset = UART_RSA_BASE << port->regshift; + unsigned int size = 8 << port->regshift; + + switch (port->iotype) { + case UPIO_HUB6: + case UPIO_PORT: + release_region(port->iobase + offset, size); + break; + default: + break; + } +} + +static void univ8250_config_port(struct uart_port *port, int flags) +{ + struct uart_8250_port *up = up_to_u8250p(port); + unsigned int i; + + up->probe &= ~UART_PROBE_RSA; + if (port->type == PORT_RSA) { + if (rsa8250_request_resource(up) == 0) + up->probe |= UART_PROBE_RSA; + } else if (flags & UART_CONFIG_TYPE) { + for (i = 0; i < probe_rsa_count; i++) { + if (probe_rsa[i] == up->port.iobase) { + if (rsa8250_request_resource(up) == 0) + up->probe |= UART_PROBE_RSA; + break; + } + } + } + + univ8250_port_base_ops->config_port(port, flags); + + if (port->type != PORT_RSA && up->probe & UART_PROBE_RSA) + rsa8250_release_resource(up); +} + +static int univ8250_request_port(struct uart_port *port) +{ + struct uart_8250_port *up = up_to_u8250p(port); + int ret; + + ret = univ8250_port_base_ops->request_port(port); + if (ret == 0 && port->type == PORT_RSA) { + ret = rsa8250_request_resource(up); + if (ret < 0) + univ8250_port_base_ops->release_port(port); + } + + return ret; +} + +static void univ8250_release_port(struct uart_port *port) +{ + struct uart_8250_port *up = up_to_u8250p(port); + + if (port->type == PORT_RSA) + rsa8250_release_resource(up); + univ8250_port_base_ops->release_port(port); +} + +void univ8250_rsa_support(struct uart_ops *ops) +{ + ops->config_port = univ8250_config_port; + ops->request_port = univ8250_request_port; + ops->release_port = univ8250_release_port; +} + +module_param_hw_array(probe_rsa, ulong, ioport, &probe_rsa_count, 0444); +MODULE_PARM_DESC(probe_rsa, "Probe I/O ports for RSA"); + +#ifdef CONFIG_SERIAL_8250_DEPRECATED_OPTIONS +#ifndef MODULE +/* + * Keep the old "8250" name working as well for the module options so we don't + * break people. We need to keep the names identical and the convenient macros + * will happily refuse to let us do that by failing the build with redefinition + * errors of global variables. So we stick them inside a dummy function to + * avoid those conflicts. The options still get parsed, and the redefined + * MODULE_PARAM_PREFIX lets us keep the "8250." syntax alive. + * + * This is hacky. I'm sorry. + */ +static void __used rsa8250_options(void) +{ +#undef MODULE_PARAM_PREFIX +#define MODULE_PARAM_PREFIX "8250_core." + + __module_param_call(MODULE_PARAM_PREFIX, probe_rsa, + ¶m_array_ops, .arr = &__param_arr_probe_rsa, + 0444, -1, 0); +} +#endif +#endif |