V4L/DVB (13100): cx23885: Add IR input keypress handling and enable for the HVR-1850

This changes adds IR Rx keypress input event handling to the CX23885 module.
This change specifically only adds input handling for IR devices implemented as
v4l2_subdevices, using only the pulse width mode (for now), and only with
RC-5 remotes.  The V4L-DVB infrastructure is missing too much to support RC-6
mode 6A as used in many media center remotes.   The grey Hauppauge RC-5 remote
and HVR-1850 IR receiver work now.

Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 418 insertions, 0 deletions

diff --git a/drivers/media/video/cx23885/cx23885-input.c b/drivers/media/video/cx23885/cx23885-input.c
new file mode 100644
index 000000000000..c208079f4e9d
--- /dev/null
+++ b/drivers/media/video/cx23885/cx23885-input.c
@@ -0,0 +1,418 @@
+/*
+ *  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->code);
+        }
+        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:
+                /*
+                 * 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:
+                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:
+                /*
+                 * 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:
+                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:
+                /* 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));
+
+        ir_input_init(input_dev, &ir->ir, ir_type, ir_codes);
+        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 = input_register_device(ir->dev);
+        if (ret)
+                goto err_out_stop;
+
+        return 0;
+
+err_out_stop:
+        cx23885_input_ir_stop(dev);
+        dev->ir_input = NULL;
+err_out_free:
+        input_free_device(input_dev);
+        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;
+        input_unregister_device(dev->ir_input->dev);
+        kfree(dev->ir_input);
+        dev->ir_input = NULL;
+}