Linux 2.6.34-rc3

[pohmelfs.git] / drivers / media / video / cx23885 / cx23885-input.c

/*
 *  Driver for the Conexant CX23885/7/8 PCIe bridge
 *
 *  Infrared remote control input device
 *
 *  Most of this file is
 *
 *  Copyright (C) 2009  Andy Walls <awalls@radix.net>
 *
 *  However, the cx23885_input_{init,fini} functions contained herein are
 *  derived from Linux kernel files linux/media/video/.../...-input.c marked as:
 *
 *  Copyright (C) 2008 <srinivasa.deevi at conexant dot com>
 *  Copyright (C) 2005 Ludovico Cavedon <cavedon@sssup.it>
 *                     Markus Rechberger <mrechberger@gmail.com>
 *                     Mauro Carvalho Chehab <mchehab@infradead.org>
 *                     Sascha Sommer <saschasommer@freenet.de>
 *  Copyright (C) 2004, 2005 Chris Pascoe
 *  Copyright (C) 2003, 2004 Gerd Knorr
 *  Copyright (C) 2003 Pavel Machek
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version 2
 *  of the License, or (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 *  02110-1301, USA.
 */

#include <linux/input.h>
#include <media/ir-common.h>
#include <media/v4l2-subdev.h>

#include "cx23885.h"

#define RC5_BITS                14
#define RC5_HALF_BITS           (2*RC5_BITS)
#define RC5_HALF_BITS_MASK      ((1 << RC5_HALF_BITS) - 1)

#define RC5_START_BITS_NORMAL   0x3 /* Command range  0 -  63 */
#define RC5_START_BITS_EXTENDED 0x2 /* Command range 64 - 127 */

#define RC5_EXTENDED_COMMAND_OFFSET     64

static inline unsigned int rc5_command(u32 rc5_baseband)
{
        return RC5_INSTR(rc5_baseband) +
                ((RC5_START(rc5_baseband) == RC5_START_BITS_EXTENDED)
                        ? RC5_EXTENDED_COMMAND_OFFSET : 0);
}

static void cx23885_input_process_raw_rc5(struct cx23885_dev *dev)
{
        struct card_ir *ir_input = dev->ir_input;
        unsigned int code, command;
        u32 rc5;

        /* Ignore codes that are too short to be valid RC-5 */
        if (ir_input->last_bit < (RC5_HALF_BITS - 1))
                return;

        /* The library has the manchester coding backwards; XOR to adapt. */
        code = (ir_input->code & RC5_HALF_BITS_MASK) ^ RC5_HALF_BITS_MASK;
        rc5 = ir_rc5_decode(code);

        switch (RC5_START(rc5)) {
        case RC5_START_BITS_NORMAL:
                break;
        case RC5_START_BITS_EXTENDED:
                /* Don't allow if the remote only emits standard commands */
                if (ir_input->start == RC5_START_BITS_NORMAL)
                        return;
                break;
        default:
                return;
        }

        if (ir_input->addr != RC5_ADDR(rc5))
                return;

        /* Don't generate a keypress for RC-5 auto-repeated keypresses */
        command = rc5_command(rc5);
        if (RC5_TOGGLE(rc5) != RC5_TOGGLE(ir_input->last_rc5) ||
            command != rc5_command(ir_input->last_rc5) ||
            /* Catch T == 0, CMD == 0 (e.g. '0') as first keypress after init */
            RC5_START(ir_input->last_rc5) == 0) {
                /* This keypress is differnet: not an auto repeat */
                ir_input_nokey(ir_input->dev, &ir_input->ir);
                ir_input_keydown(ir_input->dev, &ir_input->ir, command);
        }
        ir_input->last_rc5 = rc5;

        /* Schedule when we should do the key up event: ir_input_nokey() */
        mod_timer(&ir_input->timer_keyup,
                  jiffies + msecs_to_jiffies(ir_input->rc5_key_timeout));
}

static void cx23885_input_next_pulse_width_rc5(struct cx23885_dev *dev,
                                               u32 ns_pulse)
{
        const int rc5_quarterbit_ns = 444444; /* 32 cycles/36 kHz/2 = 444 us */
        struct card_ir *ir_input = dev->ir_input;
        int i, level, quarterbits, halfbits;

        if (!ir_input->active) {
                ir_input->active = 1;
                /* assume an initial space that we may not detect or measure */
                ir_input->code = 0;
                ir_input->last_bit = 0;
        }

        if (ns_pulse == V4L2_SUBDEV_IR_PULSE_RX_SEQ_END) {
                ir_input->last_bit++; /* Account for the final space */
                ir_input->active = 0;
                cx23885_input_process_raw_rc5(dev);
                return;
        }

        level = (ns_pulse & V4L2_SUBDEV_IR_PULSE_LEVEL_MASK) ? 1 : 0;

        /* Skip any leading space to sync to the start bit */
        if (ir_input->last_bit == 0 && level == 0)
                return;

        /*
         * With valid RC-5 we can get up to two consecutive half-bits in a
         * single pulse measurment.  Experiments have shown that the duration
         * of a half-bit can vary.  Make sure we always end up with an even
         * number of quarter bits at the same level (mark or space).
         */
        ns_pulse &= V4L2_SUBDEV_IR_PULSE_MAX_WIDTH_NS;
        quarterbits = ns_pulse / rc5_quarterbit_ns;
        if (quarterbits & 1)
                quarterbits++;
        halfbits = quarterbits / 2;

        for (i = 0; i < halfbits; i++) {
                ir_input->last_bit++;
                ir_input->code |= (level << ir_input->last_bit);

                if (ir_input->last_bit >= RC5_HALF_BITS-1) {
                        ir_input->active = 0;
                        cx23885_input_process_raw_rc5(dev);
                        /*
                         * If level is 1, a leading mark is invalid for RC5.
                         * If level is 0, we scan past extra intial space.
                         * Either way we don't want to reactivate collecting
                         * marks or spaces here with any left over half-bits.
                         */
                        break;
                }
        }
}

static void cx23885_input_process_pulse_widths_rc5(struct cx23885_dev *dev,
                                                   bool add_eom)
{
        struct card_ir *ir_input = dev->ir_input;
        struct ir_input_state *ir_input_state = &ir_input->ir;

        u32 ns_pulse[RC5_HALF_BITS+1];
        ssize_t num = 0;
        int count, i;

        do {
                v4l2_subdev_call(dev->sd_ir, ir, rx_read, (u8 *) ns_pulse,
                                 sizeof(ns_pulse), &num);

                count = num / sizeof(u32);

                /* Append an end of Rx seq, if the caller requested */
                if (add_eom && count < ARRAY_SIZE(ns_pulse)) {
                        ns_pulse[count] = V4L2_SUBDEV_IR_PULSE_RX_SEQ_END;
                        count++;
                }

                /* Just drain the Rx FIFO, if we're called, but not RC-5 */
                if (ir_input_state->ir_type != IR_TYPE_RC5)
                        continue;

                for (i = 0; i < count; i++)
                        cx23885_input_next_pulse_width_rc5(dev, ns_pulse[i]);
        } while (num != 0);
}

void cx23885_input_rx_work_handler(struct cx23885_dev *dev, u32 events)
{
        struct v4l2_subdev_ir_parameters params;
        int overrun, data_available;

        if (dev->sd_ir == NULL || events == 0)
                return;

        switch (dev->board) {
        case CX23885_BOARD_HAUPPAUGE_HVR1850:
        case CX23885_BOARD_HAUPPAUGE_HVR1290:
                /*
                 * The only board we handle right now.  However other boards
                 * using the CX2388x integrated IR controller should be similar
                 */
                break;
        default:
                return;
        }

        overrun = events & (V4L2_SUBDEV_IR_RX_SW_FIFO_OVERRUN |
                            V4L2_SUBDEV_IR_RX_HW_FIFO_OVERRUN);

        data_available = events & (V4L2_SUBDEV_IR_RX_END_OF_RX_DETECTED |
                                   V4L2_SUBDEV_IR_RX_FIFO_SERVICE_REQ);

        if (overrun) {
                /* If there was a FIFO overrun, stop the device */
                v4l2_subdev_call(dev->sd_ir, ir, rx_g_parameters, &params);
                params.enable = false;
                /* Mitigate race with cx23885_input_ir_stop() */
                params.shutdown = atomic_read(&dev->ir_input_stopping);
                v4l2_subdev_call(dev->sd_ir, ir, rx_s_parameters, &params);
        }

        if (data_available)
                cx23885_input_process_pulse_widths_rc5(dev, overrun);

        if (overrun) {
                /* If there was a FIFO overrun, clear & restart the device */
                params.enable = true;
                /* Mitigate race with cx23885_input_ir_stop() */
                params.shutdown = atomic_read(&dev->ir_input_stopping);
                v4l2_subdev_call(dev->sd_ir, ir, rx_s_parameters, &params);
        }
}

static void cx23885_input_ir_start(struct cx23885_dev *dev)
{
        struct card_ir *ir_input = dev->ir_input;
        struct ir_input_state *ir_input_state = &ir_input->ir;
        struct v4l2_subdev_ir_parameters params;

        if (dev->sd_ir == NULL)
                return;

        atomic_set(&dev->ir_input_stopping, 0);

        /* keyup timer set up, if needed */
        switch (dev->board) {
        case CX23885_BOARD_HAUPPAUGE_HVR1850:
        case CX23885_BOARD_HAUPPAUGE_HVR1290:
                setup_timer(&ir_input->timer_keyup,
                            ir_rc5_timer_keyup, /* Not actually RC-5 specific */
                            (unsigned long) ir_input);
                if (ir_input_state->ir_type == IR_TYPE_RC5) {
                        /*
                         * RC-5 repeats a held key every
                         * 64 bits * (2 * 32/36000) sec/bit = 113.778 ms
                         */
                        ir_input->rc5_key_timeout = 115;
                }
                break;
        }

        v4l2_subdev_call(dev->sd_ir, ir, rx_g_parameters, &params);
        switch (dev->board) {
        case CX23885_BOARD_HAUPPAUGE_HVR1850:
        case CX23885_BOARD_HAUPPAUGE_HVR1290:
                /*
                 * The IR controller on this board only returns pulse widths.
                 * Any other mode setting will fail to set up the device.
                */
                params.mode = V4L2_SUBDEV_IR_MODE_PULSE_WIDTH;
                params.enable = true;
                params.interrupt_enable = true;
                params.shutdown = false;

                /* Setup for baseband compatible with both RC-5 and RC-6A */
                params.modulation = false;
                /* RC-5:  2,222,222 ns = 1/36 kHz * 32 cycles * 2 marks * 1.25*/
                /* RC-6A: 3,333,333 ns = 1/36 kHz * 16 cycles * 6 marks * 1.25*/
                params.max_pulse_width = 3333333; /* ns */
                /* RC-5:    666,667 ns = 1/36 kHz * 32 cycles * 1 mark * 0.75 */
                /* RC-6A:   333,333 ns = 1/36 kHz * 16 cycles * 1 mark * 0.75 */
                params.noise_filter_min_width = 333333; /* ns */
                /*
                 * This board has inverted receive sense:
                 * mark is received as low logic level;
                 * falling edges are detected as rising edges; etc.
                 */
                params.invert = true;
                break;
        }
        v4l2_subdev_call(dev->sd_ir, ir, rx_s_parameters, &params);
}

static void cx23885_input_ir_stop(struct cx23885_dev *dev)
{
        struct card_ir *ir_input = dev->ir_input;
        struct v4l2_subdev_ir_parameters params;

        if (dev->sd_ir == NULL)
                return;

        /*
         * Stop the sd_ir subdevice from generating notifications and
         * scheduling work.
         * It is shutdown this way in order to mitigate a race with
         * cx23885_input_rx_work_handler() in the overrun case, which could
         * re-enable the subdevice.
         */
        atomic_set(&dev->ir_input_stopping, 1);
        v4l2_subdev_call(dev->sd_ir, ir, rx_g_parameters, &params);
        while (params.shutdown == false) {
                params.enable = false;
                params.interrupt_enable = false;
                params.shutdown = true;
                v4l2_subdev_call(dev->sd_ir, ir, rx_s_parameters, &params);
                v4l2_subdev_call(dev->sd_ir, ir, rx_g_parameters, &params);
        }

        flush_scheduled_work();

        switch (dev->board) {
        case CX23885_BOARD_HAUPPAUGE_HVR1850:
        case CX23885_BOARD_HAUPPAUGE_HVR1290:
                del_timer_sync(&ir_input->timer_keyup);
                break;
        }
}

int cx23885_input_init(struct cx23885_dev *dev)
{
        struct card_ir *ir;
        struct input_dev *input_dev;
        struct ir_scancode_table *ir_codes = NULL;
        int ir_type, ir_addr, ir_start;
        int ret;

        /*
         * If the IR device (hardware registers, chip, GPIO lines, etc.) isn't
         * encapsulated in a v4l2_subdev, then I'm not going to deal with it.
         */
        if (dev->sd_ir == NULL)
                return -ENODEV;

        switch (dev->board) {
        case CX23885_BOARD_HAUPPAUGE_HVR1850:
        case CX23885_BOARD_HAUPPAUGE_HVR1290:
                /* Parameters for the grey Hauppauge remote for the HVR-1850 */
                ir_codes = &ir_codes_hauppauge_new_table;
                ir_type = IR_TYPE_RC5;
                ir_addr = 0x1e; /* RC-5 system bits emitted by the remote */
                ir_start = RC5_START_BITS_NORMAL; /* A basic RC-5 remote */
                break;
        }
        if (ir_codes == NULL)
                return -ENODEV;

        ir = kzalloc(sizeof(*ir), GFP_KERNEL);
        input_dev = input_allocate_device();
        if (!ir || !input_dev) {
                ret = -ENOMEM;
                goto err_out_free;
        }

        ir->dev = input_dev;
        ir->addr = ir_addr;
        ir->start = ir_start;

        /* init input device */
        snprintf(ir->name, sizeof(ir->name), "cx23885 IR (%s)",
                 cx23885_boards[dev->board].name);
        snprintf(ir->phys, sizeof(ir->phys), "pci-%s/ir0", pci_name(dev->pci));

        ret = ir_input_init(input_dev, &ir->ir, ir_type);
        if (ret < 0)
                goto err_out_free;

        input_dev->name = ir->name;
        input_dev->phys = ir->phys;
        input_dev->id.bustype = BUS_PCI;
        input_dev->id.version = 1;
        if (dev->pci->subsystem_vendor) {
                input_dev->id.vendor  = dev->pci->subsystem_vendor;
                input_dev->id.product = dev->pci->subsystem_device;
        } else {
                input_dev->id.vendor  = dev->pci->vendor;
                input_dev->id.product = dev->pci->device;
        }
        input_dev->dev.parent = &dev->pci->dev;

        dev->ir_input = ir;
        cx23885_input_ir_start(dev);

        ret = ir_input_register(ir->dev, ir_codes, NULL);
        if (ret)
                goto err_out_stop;

        return 0;

err_out_stop:
        cx23885_input_ir_stop(dev);
        dev->ir_input = NULL;
err_out_free:
        kfree(ir);
        return ret;
}

void cx23885_input_fini(struct cx23885_dev *dev)
{
        /* Always stop the IR hardware from generating interrupts */
        cx23885_input_ir_stop(dev);

        if (dev->ir_input == NULL)
                return;
        ir_input_unregister(dev->ir_input->dev);
        kfree(dev->ir_input);
        dev->ir_input = NULL;
}