diff options
Diffstat (limited to 'drivers/media/pci/mantis/mantis_uart.c')
| -rw-r--r-- | drivers/media/pci/mantis/mantis_uart.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/drivers/media/pci/mantis/mantis_uart.c b/drivers/media/pci/mantis/mantis_uart.c new file mode 100644 index 000000000..42983a89e --- /dev/null +++ b/drivers/media/pci/mantis/mantis_uart.c @@ -0,0 +1,186 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + Mantis PCI bridge driver + + Copyright (C) Manu Abraham (abraham.manu@gmail.com) + +*/ + +#include <linux/kernel.h> +#include <linux/spinlock.h> +#include <asm/io.h> + +#include <linux/signal.h> +#include <linux/sched.h> +#include <linux/interrupt.h> +#include <linux/pci.h> + +#include <media/dmxdev.h> +#include <media/dvbdev.h> +#include <media/dvb_demux.h> +#include <media/dvb_frontend.h> +#include <media/dvb_net.h> + +#include "mantis_common.h" +#include "mantis_reg.h" +#include "mantis_uart.h" +#include "mantis_input.h" + +struct mantis_uart_params { + enum mantis_baud baud_rate; + enum mantis_parity parity; +}; + +static struct { + char string[7]; +} rates[5] = { + { "9600" }, + { "19200" }, + { "38400" }, + { "57600" }, + { "115200" } +}; + +static struct { + char string[5]; +} parity[3] = { + { "NONE" }, + { "ODD" }, + { "EVEN" } +}; + +static void mantis_uart_read(struct mantis_pci *mantis) +{ + struct mantis_hwconfig *config = mantis->hwconfig; + int i, scancode = 0, err = 0; + + /* get data */ + dprintk(MANTIS_DEBUG, 1, "UART Reading ..."); + for (i = 0; i < (config->bytes + 1); i++) { + int data = mmread(MANTIS_UART_RXD); + + dprintk(MANTIS_DEBUG, 0, " <%02x>", data); + + scancode = (scancode << 8) | (data & 0x3f); + err |= data; + + if (data & (1 << 7)) + dprintk(MANTIS_ERROR, 1, "UART framing error"); + + if (data & (1 << 6)) + dprintk(MANTIS_ERROR, 1, "UART parity error"); + } + dprintk(MANTIS_DEBUG, 0, "\n"); + + if ((err & 0xC0) == 0) + mantis_input_process(mantis, scancode); +} + +static void mantis_uart_work(struct work_struct *work) +{ + struct mantis_pci *mantis = container_of(work, struct mantis_pci, uart_work); + u32 stat; + unsigned long timeout; + + stat = mmread(MANTIS_UART_STAT); + + if (stat & MANTIS_UART_RXFIFO_FULL) + dprintk(MANTIS_ERROR, 1, "RX Fifo FULL"); + + /* + * MANTIS_UART_RXFIFO_DATA is only set if at least + * config->bytes + 1 bytes are in the FIFO. + */ + + /* FIXME: is 10ms good enough ? */ + timeout = jiffies + msecs_to_jiffies(10); + while (stat & MANTIS_UART_RXFIFO_DATA) { + mantis_uart_read(mantis); + stat = mmread(MANTIS_UART_STAT); + + if (!time_is_after_jiffies(timeout)) + break; + } + + /* re-enable UART (RX) interrupt */ + mantis_unmask_ints(mantis, MANTIS_INT_IRQ1); +} + +static int mantis_uart_setup(struct mantis_pci *mantis, + struct mantis_uart_params *params) +{ + u32 reg; + + mmwrite((mmread(MANTIS_UART_CTL) | (params->parity & 0x3)), MANTIS_UART_CTL); + + reg = mmread(MANTIS_UART_BAUD); + + switch (params->baud_rate) { + case MANTIS_BAUD_9600: + reg |= 0xd8; + break; + case MANTIS_BAUD_19200: + reg |= 0x6c; + break; + case MANTIS_BAUD_38400: + reg |= 0x36; + break; + case MANTIS_BAUD_57600: + reg |= 0x23; + break; + case MANTIS_BAUD_115200: + reg |= 0x11; + break; + default: + return -EINVAL; + } + + mmwrite(reg, MANTIS_UART_BAUD); + + return 0; +} + +int mantis_uart_init(struct mantis_pci *mantis) +{ + struct mantis_hwconfig *config = mantis->hwconfig; + struct mantis_uart_params params; + + /* default parity: */ + params.baud_rate = config->baud_rate; + params.parity = config->parity; + dprintk(MANTIS_INFO, 1, "Initializing UART @ %sbps parity:%s", + rates[params.baud_rate].string, + parity[params.parity].string); + + INIT_WORK(&mantis->uart_work, mantis_uart_work); + + /* disable interrupt */ + mmwrite(mmread(MANTIS_UART_CTL) & 0xffef, MANTIS_UART_CTL); + + mantis_uart_setup(mantis, ¶ms); + + /* default 1 byte */ + mmwrite((mmread(MANTIS_UART_BAUD) | (config->bytes << 8)), MANTIS_UART_BAUD); + + /* flush buffer */ + mmwrite((mmread(MANTIS_UART_CTL) | MANTIS_UART_RXFLUSH), MANTIS_UART_CTL); + + /* enable interrupt */ + mmwrite(mmread(MANTIS_UART_CTL) | MANTIS_UART_RXINT, MANTIS_UART_CTL); + mantis_unmask_ints(mantis, MANTIS_INT_IRQ1); + + schedule_work(&mantis->uart_work); + dprintk(MANTIS_DEBUG, 1, "UART successfully initialized"); + + return 0; +} +EXPORT_SYMBOL_GPL(mantis_uart_init); + +void mantis_uart_exit(struct mantis_pci *mantis) +{ + /* disable interrupt */ + mantis_mask_ints(mantis, MANTIS_INT_IRQ1); + mmwrite(mmread(MANTIS_UART_CTL) & 0xffef, MANTIS_UART_CTL); + flush_work(&mantis->uart_work); +} +EXPORT_SYMBOL_GPL(mantis_uart_exit); |