drivers/media/rc/meson-ir.c

   1 /*
   2  * Driver for Amlogic Meson IR remote receiver
   3  *
   4  * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com>
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * version 2 as published by the Free Software Foundation.
   9  *
  10  * You should have received a copy of the GNU General Public License
  11  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  12  */
  13
  14 #include <linux/device.h>
  15 #include <linux/err.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/io.h>
  18 #include <linux/module.h>
  19 #include <linux/of_platform.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/spinlock.h>
  22
  23 #include <media/rc-core.h>
  24
  25 #define DRIVER_NAME             "meson-ir"
  26
  27 /* valid on all Meson platforms */
  28 #define IR_DEC_LDR_ACTIVE       0x00
  29 #define IR_DEC_LDR_IDLE         0x04
  30 #define IR_DEC_LDR_REPEAT       0x08
  31 #define IR_DEC_BIT_0            0x0c
  32 #define IR_DEC_REG0             0x10
  33 #define IR_DEC_FRAME            0x14
  34 #define IR_DEC_STATUS           0x18
  35 #define IR_DEC_REG1             0x1c
  36 /* only available on Meson 8b and newer */
  37 #define IR_DEC_REG2             0x20
  38
  39 #define REG0_RATE_MASK          (BIT(11) - 1)
  40
  41 #define DECODE_MODE_NEC         0x0
  42 #define DECODE_MODE_RAW         0x2
  43
  44 /* Meson 6b uses REG1 to configure the mode */
  45 #define REG1_MODE_MASK          GENMASK(8, 7)
  46 #define REG1_MODE_SHIFT         7
  47
  48 /* Meson 8b / GXBB use REG2 to configure the mode */
  49 #define REG2_MODE_MASK          GENMASK(3, 0)
  50 #define REG2_MODE_SHIFT         0
  51
  52 #define REG1_TIME_IV_SHIFT      16
  53 #define REG1_TIME_IV_MASK       ((BIT(13) - 1) << REG1_TIME_IV_SHIFT)
  54
  55 #define REG1_IRQSEL_MASK        (BIT(2) | BIT(3))
  56 #define REG1_IRQSEL_NEC_MODE    (0 << 2)
  57 #define REG1_IRQSEL_RISE_FALL   (1 << 2)
  58 #define REG1_IRQSEL_FALL        (2 << 2)
  59 #define REG1_IRQSEL_RISE        (3 << 2)
  60
  61 #define REG1_RESET              BIT(0)
  62 #define REG1_ENABLE             BIT(15)
  63
  64 #define STATUS_IR_DEC_IN        BIT(8)
  65
  66 #define MESON_TRATE             10      /* us */
  67
  68 struct meson_ir {
  69         void __iomem    *reg;
  70         struct rc_dev   *rc;
  71         int             irq;
  72         spinlock_t      lock;
  73 };
  74
  75 static void meson_ir_set_mask(struct meson_ir *ir, unsigned int reg,
  76                               u32 mask, u32 value)
  77 {
  78         u32 data;
  79
  80         data = readl(ir->reg + reg);
  81         data &= ~mask;
  82         data |= (value & mask);
  83         writel(data, ir->reg + reg);
  84 }
  85
  86 static irqreturn_t meson_ir_irq(int irqno, void *dev_id)
  87 {
  88         struct meson_ir *ir = dev_id;
  89         u32 duration;
  90         DEFINE_IR_RAW_EVENT(rawir);
  91
  92         spin_lock(&ir->lock);
  93
  94         duration = readl(ir->reg + IR_DEC_REG1);
  95         duration = (duration & REG1_TIME_IV_MASK) >> REG1_TIME_IV_SHIFT;
  96         rawir.duration = US_TO_NS(duration * MESON_TRATE);
  97
  98         rawir.pulse = !!(readl(ir->reg + IR_DEC_STATUS) & STATUS_IR_DEC_IN);
  99
 100         ir_raw_event_store_with_filter(ir->rc, &rawir);
 101         ir_raw_event_handle(ir->rc);
 102
 103         spin_unlock(&ir->lock);
 104
 105         return IRQ_HANDLED;
 106 }
 107
 108 static int meson_ir_probe(struct platform_device *pdev)
 109 {
 110         struct device *dev = &pdev->dev;
 111         struct device_node *node = dev->of_node;
 112         struct resource *res;
 113         const char *map_name;
 114         struct meson_ir *ir;
 115         int ret;
 116
 117         ir = devm_kzalloc(dev, sizeof(struct meson_ir), GFP_KERNEL);
 118         if (!ir)
 119                 return -ENOMEM;
 120
 121         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 122         ir->reg = devm_ioremap_resource(dev, res);
 123         if (IS_ERR(ir->reg)) {
 124                 dev_err(dev, "failed to map registers\n");
 125                 return PTR_ERR(ir->reg);
 126         }
 127
 128         ir->irq = platform_get_irq(pdev, 0);
 129         if (ir->irq < 0) {
 130                 dev_err(dev, "no irq resource\n");
 131                 return ir->irq;
 132         }
 133
 134         ir->rc = rc_allocate_device(RC_DRIVER_IR_RAW);
 135         if (!ir->rc) {
 136                 dev_err(dev, "failed to allocate rc device\n");
 137                 return -ENOMEM;
 138         }
 139
 140         ir->rc->priv = ir;
 141         ir->rc->input_name = DRIVER_NAME;
 142         ir->rc->input_phys = DRIVER_NAME "/input0";
 143         ir->rc->input_id.bustype = BUS_HOST;
 144         map_name = of_get_property(node, "linux,rc-map-name", NULL);
 145         ir->rc->map_name = map_name ? map_name : RC_MAP_EMPTY;
 146         ir->rc->dev.parent = dev;
 147         ir->rc->allowed_protocols = RC_BIT_ALL_IR_DECODER;
 148         ir->rc->rx_resolution = US_TO_NS(MESON_TRATE);
 149         ir->rc->timeout = MS_TO_NS(200);
 150         ir->rc->driver_name = DRIVER_NAME;
 151
 152         spin_lock_init(&ir->lock);
 153         platform_set_drvdata(pdev, ir);
 154
 155         ret = rc_register_device(ir->rc);
 156         if (ret) {
 157                 dev_err(dev, "failed to register rc device\n");
 158                 goto out_free;
 159         }
 160
 161         ret = devm_request_irq(dev, ir->irq, meson_ir_irq, 0, "ir-meson", ir);
 162         if (ret) {
 163                 dev_err(dev, "failed to request irq\n");
 164                 goto out_unreg;
 165         }
 166
 167         /* Reset the decoder */
 168         meson_ir_set_mask(ir, IR_DEC_REG1, REG1_RESET, REG1_RESET);
 169         meson_ir_set_mask(ir, IR_DEC_REG1, REG1_RESET, 0);
 170
 171         /* Set general operation mode (= raw/software decoding) */
 172         if (of_device_is_compatible(node, "amlogic,meson6-ir"))
 173                 meson_ir_set_mask(ir, IR_DEC_REG1, REG1_MODE_MASK,
 174                                   DECODE_MODE_RAW << REG1_MODE_SHIFT);
 175         else
 176                 meson_ir_set_mask(ir, IR_DEC_REG2, REG2_MODE_MASK,
 177                                   DECODE_MODE_RAW << REG2_MODE_SHIFT);
 178
 179         /* Set rate */
 180         meson_ir_set_mask(ir, IR_DEC_REG0, REG0_RATE_MASK, MESON_TRATE - 1);
 181         /* IRQ on rising and falling edges */
 182         meson_ir_set_mask(ir, IR_DEC_REG1, REG1_IRQSEL_MASK,
 183                           REG1_IRQSEL_RISE_FALL);
 184         /* Enable the decoder */
 185         meson_ir_set_mask(ir, IR_DEC_REG1, REG1_ENABLE, REG1_ENABLE);
 186
 187         dev_info(dev, "receiver initialized\n");
 188
 189         return 0;
 190 out_unreg:
 191         rc_unregister_device(ir->rc);
 192         ir->rc = NULL;
 193 out_free:
 194         rc_free_device(ir->rc);
 195
 196         return ret;
 197 }
 198
 199 static int meson_ir_remove(struct platform_device *pdev)
 200 {
 201         struct meson_ir *ir = platform_get_drvdata(pdev);
 202         unsigned long flags;
 203
 204         /* Disable the decoder */
 205         spin_lock_irqsave(&ir->lock, flags);
 206         meson_ir_set_mask(ir, IR_DEC_REG1, REG1_ENABLE, 0);
 207         spin_unlock_irqrestore(&ir->lock, flags);
 208
 209         rc_unregister_device(ir->rc);
 210
 211         return 0;
 212 }
 213
 214 static const struct of_device_id meson_ir_match[] = {
 215         { .compatible = "amlogic,meson6-ir" },
 216         { .compatible = "amlogic,meson8b-ir" },
 217         { .compatible = "amlogic,meson-gxbb-ir" },
 218         { },
 219 };
 220 MODULE_DEVICE_TABLE(of, meson_ir_match);
 221
 222 static struct platform_driver meson_ir_driver = {
 223         .probe          = meson_ir_probe,
 224         .remove         = meson_ir_remove,
 225         .driver = {
 226                 .name           = DRIVER_NAME,
 227                 .of_match_table = meson_ir_match,
 228         },
 229 };
 230
 231 module_platform_driver(meson_ir_driver);
 232
 233 MODULE_DESCRIPTION("Amlogic Meson IR remote receiver driver");
 234 MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
 235 MODULE_LICENSE("GPL v2");