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 #define IR_DEC_LDR_ACTIVE       0x00
  28 #define IR_DEC_LDR_IDLE         0x04
  29 #define IR_DEC_LDR_REPEAT       0x08
  30 #define IR_DEC_BIT_0            0x0c
  31 #define IR_DEC_REG0             0x10
  32 #define IR_DEC_FRAME            0x14
  33 #define IR_DEC_STATUS           0x18
  34 #define IR_DEC_REG1             0x1c
  35
  36 #define REG0_RATE_MASK          (BIT(11) - 1)
  37
  38 #define REG1_MODE_MASK          (BIT(7) | BIT(8))
  39 #define REG1_MODE_NEC           (0 << 7)
  40 #define REG1_MODE_GENERAL       (2 << 7)
  41
  42 #define REG1_TIME_IV_SHIFT      16
  43 #define REG1_TIME_IV_MASK       ((BIT(13) - 1) << REG1_TIME_IV_SHIFT)
  44
  45 #define REG1_IRQSEL_MASK        (BIT(2) | BIT(3))
  46 #define REG1_IRQSEL_NEC_MODE    (0 << 2)
  47 #define REG1_IRQSEL_RISE_FALL   (1 << 2)
  48 #define REG1_IRQSEL_FALL        (2 << 2)
  49 #define REG1_IRQSEL_RISE        (3 << 2)
  50
  51 #define REG1_RESET              BIT(0)
  52 #define REG1_ENABLE             BIT(15)
  53
  54 #define STATUS_IR_DEC_IN        BIT(8)
  55
  56 #define MESON_TRATE             10      /* us */
  57
  58 struct meson_ir {
  59         void __iomem    *reg;
  60         struct rc_dev   *rc;
  61         int             irq;
  62         spinlock_t      lock;
  63 };
  64
  65 static void meson_ir_set_mask(struct meson_ir *ir, unsigned int reg,
  66                               u32 mask, u32 value)
  67 {
  68         u32 data;
  69
  70         data = readl(ir->reg + reg);
  71         data &= ~mask;
  72         data |= (value & mask);
  73         writel(data, ir->reg + reg);
  74 }
  75
  76 static irqreturn_t meson_ir_irq(int irqno, void *dev_id)
  77 {
  78         struct meson_ir *ir = dev_id;
  79         u32 duration;
  80         DEFINE_IR_RAW_EVENT(rawir);
  81
  82         spin_lock(&ir->lock);
  83
  84         duration = readl(ir->reg + IR_DEC_REG1);
  85         duration = (duration & REG1_TIME_IV_MASK) >> REG1_TIME_IV_SHIFT;
  86         rawir.duration = US_TO_NS(duration * MESON_TRATE);
  87
  88         rawir.pulse = !!(readl(ir->reg + IR_DEC_STATUS) & STATUS_IR_DEC_IN);
  89
  90         ir_raw_event_store_with_filter(ir->rc, &rawir);
  91         ir_raw_event_handle(ir->rc);
  92
  93         spin_unlock(&ir->lock);
  94
  95         return IRQ_HANDLED;
  96 }
  97
  98 static int meson_ir_probe(struct platform_device *pdev)
  99 {
 100         struct device *dev = &pdev->dev;
 101         struct device_node *node = dev->of_node;
 102         struct resource *res;
 103         const char *map_name;
 104         struct meson_ir *ir;
 105         int ret;
 106
 107         ir = devm_kzalloc(dev, sizeof(struct meson_ir), GFP_KERNEL);
 108         if (!ir)
 109                 return -ENOMEM;
 110
 111         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 112         ir->reg = devm_ioremap_resource(dev, res);
 113         if (IS_ERR(ir->reg)) {
 114                 dev_err(dev, "failed to map registers\n");
 115                 return PTR_ERR(ir->reg);
 116         }
 117
 118         ir->irq = platform_get_irq(pdev, 0);
 119         if (ir->irq < 0) {
 120                 dev_err(dev, "no irq resource\n");
 121                 return ir->irq;
 122         }
 123
 124         ir->rc = rc_allocate_device();
 125         if (!ir->rc) {
 126                 dev_err(dev, "failed to allocate rc device\n");
 127                 return -ENOMEM;
 128         }
 129
 130         ir->rc->priv = ir;
 131         ir->rc->input_name = DRIVER_NAME;
 132         ir->rc->input_phys = DRIVER_NAME "/input0";
 133         ir->rc->input_id.bustype = BUS_HOST;
 134         map_name = of_get_property(node, "linux,rc-map-name", NULL);
 135         ir->rc->map_name = map_name ? map_name : RC_MAP_EMPTY;
 136         ir->rc->dev.parent = dev;
 137         ir->rc->driver_type = RC_DRIVER_IR_RAW;
 138         ir->rc->allowed_protocols = RC_BIT_ALL;
 139         ir->rc->rx_resolution = US_TO_NS(MESON_TRATE);
 140         ir->rc->timeout = MS_TO_NS(200);
 141         ir->rc->driver_name = DRIVER_NAME;
 142
 143         spin_lock_init(&ir->lock);
 144         platform_set_drvdata(pdev, ir);
 145
 146         ret = rc_register_device(ir->rc);
 147         if (ret) {
 148                 dev_err(dev, "failed to register rc device\n");
 149                 goto out_free;
 150         }
 151
 152         ret = devm_request_irq(dev, ir->irq, meson_ir_irq, 0, "ir-meson", ir);
 153         if (ret) {
 154                 dev_err(dev, "failed to request irq\n");
 155                 goto out_unreg;
 156         }
 157
 158         /* Reset the decoder */
 159         meson_ir_set_mask(ir, IR_DEC_REG1, REG1_RESET, REG1_RESET);
 160         meson_ir_set_mask(ir, IR_DEC_REG1, REG1_RESET, 0);
 161         /* Set general operation mode */
 162         meson_ir_set_mask(ir, IR_DEC_REG1, REG1_MODE_MASK, REG1_MODE_GENERAL);
 163         /* Set rate */
 164         meson_ir_set_mask(ir, IR_DEC_REG0, REG0_RATE_MASK, MESON_TRATE - 1);
 165         /* IRQ on rising and falling edges */
 166         meson_ir_set_mask(ir, IR_DEC_REG1, REG1_IRQSEL_MASK,
 167                           REG1_IRQSEL_RISE_FALL);
 168         /* Enable the decoder */
 169         meson_ir_set_mask(ir, IR_DEC_REG1, REG1_ENABLE, REG1_ENABLE);
 170
 171         dev_info(dev, "receiver initialized\n");
 172
 173         return 0;
 174 out_unreg:
 175         rc_unregister_device(ir->rc);
 176         ir->rc = NULL;
 177 out_free:
 178         rc_free_device(ir->rc);
 179
 180         return ret;
 181 }
 182
 183 static int meson_ir_remove(struct platform_device *pdev)
 184 {
 185         struct meson_ir *ir = platform_get_drvdata(pdev);
 186         unsigned long flags;
 187
 188         /* Disable the decoder */
 189         spin_lock_irqsave(&ir->lock, flags);
 190         meson_ir_set_mask(ir, IR_DEC_REG1, REG1_ENABLE, 0);
 191         spin_unlock_irqrestore(&ir->lock, flags);
 192
 193         rc_unregister_device(ir->rc);
 194
 195         return 0;
 196 }
 197
 198 static const struct of_device_id meson_ir_match[] = {
 199         { .compatible = "amlogic,meson6-ir" },
 200         { },
 201 };
 202
 203 static struct platform_driver meson_ir_driver = {
 204         .probe          = meson_ir_probe,
 205         .remove         = meson_ir_remove,
 206         .driver = {
 207                 .name           = DRIVER_NAME,
 208                 .of_match_table = meson_ir_match,
 209         },
 210 };
 211
 212 module_platform_driver(meson_ir_driver);
 213
 214 MODULE_DESCRIPTION("Amlogic Meson IR remote receiver driver");
 215 MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
 216 MODULE_LICENSE("GPL v2");