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 #include <linux/bitfield.h>
  23
  24 #include <media/rc-core.h>
  25
  26 #define DRIVER_NAME             "meson-ir"
  27
  28 /* valid on all Meson platforms */
  29 #define IR_DEC_LDR_ACTIVE       0x00
  30 #define IR_DEC_LDR_IDLE         0x04
  31 #define IR_DEC_LDR_REPEAT       0x08
  32 #define IR_DEC_BIT_0            0x0c
  33 #define IR_DEC_REG0             0x10
  34 #define IR_DEC_FRAME            0x14
  35 #define IR_DEC_STATUS           0x18
  36 #define IR_DEC_REG1             0x1c
  37 /* only available on Meson 8b and newer */
  38 #define IR_DEC_REG2             0x20
  39
  40 #define REG0_RATE_MASK          GENMASK(11, 0)
  41
  42 #define DECODE_MODE_NEC         0x0
  43 #define DECODE_MODE_RAW         0x2
  44
  45 /* Meson 6b uses REG1 to configure the mode */
  46 #define REG1_MODE_MASK          GENMASK(8, 7)
  47 #define REG1_MODE_SHIFT         7
  48
  49 /* Meson 8b / GXBB use REG2 to configure the mode */
  50 #define REG2_MODE_MASK          GENMASK(3, 0)
  51 #define REG2_MODE_SHIFT         0
  52
  53 #define REG1_TIME_IV_MASK       GENMASK(28, 16)
  54
  55 #define REG1_IRQSEL_MASK        GENMASK(3, 2)
  56 #define REG1_IRQSEL_NEC_MODE    0
  57 #define REG1_IRQSEL_RISE_FALL   1
  58 #define REG1_IRQSEL_FALL        2
  59 #define REG1_IRQSEL_RISE        3
  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         spinlock_t      lock;
  72 };
  73
  74 static void meson_ir_set_mask(struct meson_ir *ir, unsigned int reg,
  75                               u32 mask, u32 value)
  76 {
  77         u32 data;
  78
  79         data = readl(ir->reg + reg);
  80         data &= ~mask;
  81         data |= (value & mask);
  82         writel(data, ir->reg + reg);
  83 }
  84
  85 static irqreturn_t meson_ir_irq(int irqno, void *dev_id)
  86 {
  87         struct meson_ir *ir = dev_id;
  88         u32 duration, status;
  89         DEFINE_IR_RAW_EVENT(rawir);
  90
  91         spin_lock(&ir->lock);
  92
  93         duration = readl_relaxed(ir->reg + IR_DEC_REG1);
  94         duration = FIELD_GET(REG1_TIME_IV_MASK, duration);
  95         rawir.duration = US_TO_NS(duration * MESON_TRATE);
  96
  97         status = readl_relaxed(ir->reg + IR_DEC_STATUS);
  98         rawir.pulse = !!(status & STATUS_IR_DEC_IN);
  99
 100         ir_raw_event_store(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 irq, 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         irq = platform_get_irq(pdev, 0);
 129         if (irq < 0) {
 130                 dev_err(dev, "no irq resource\n");
 131                 return irq;
 132         }
 133
 134         ir->rc = devm_rc_allocate_device(dev, 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->device_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->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
 147         ir->rc->rx_resolution = US_TO_NS(MESON_TRATE);
 148         ir->rc->timeout = MS_TO_NS(200);
 149         ir->rc->driver_name = DRIVER_NAME;
 150
 151         spin_lock_init(&ir->lock);
 152         platform_set_drvdata(pdev, ir);
 153
 154         ret = devm_rc_register_device(dev, ir->rc);
 155         if (ret) {
 156                 dev_err(dev, "failed to register rc device\n");
 157                 return ret;
 158         }
 159
 160         ret = devm_request_irq(dev, irq, meson_ir_irq, 0, NULL, ir);
 161         if (ret) {
 162                 dev_err(dev, "failed to request irq\n");
 163                 return ret;
 164         }
 165
 166         /* Reset the decoder */
 167         meson_ir_set_mask(ir, IR_DEC_REG1, REG1_RESET, REG1_RESET);
 168         meson_ir_set_mask(ir, IR_DEC_REG1, REG1_RESET, 0);
 169
 170         /* Set general operation mode (= raw/software decoding) */
 171         if (of_device_is_compatible(node, "amlogic,meson6-ir"))
 172                 meson_ir_set_mask(ir, IR_DEC_REG1, REG1_MODE_MASK,
 173                                   FIELD_PREP(REG1_MODE_MASK, DECODE_MODE_RAW));
 174         else
 175                 meson_ir_set_mask(ir, IR_DEC_REG2, REG2_MODE_MASK,
 176                                   FIELD_PREP(REG2_MODE_MASK, DECODE_MODE_RAW));
 177
 178         /* Set rate */
 179         meson_ir_set_mask(ir, IR_DEC_REG0, REG0_RATE_MASK, MESON_TRATE - 1);
 180         /* IRQ on rising and falling edges */
 181         meson_ir_set_mask(ir, IR_DEC_REG1, REG1_IRQSEL_MASK,
 182                           FIELD_PREP(REG1_IRQSEL_MASK, REG1_IRQSEL_RISE_FALL));
 183         /* Enable the decoder */
 184         meson_ir_set_mask(ir, IR_DEC_REG1, REG1_ENABLE, REG1_ENABLE);
 185
 186         dev_info(dev, "receiver initialized\n");
 187
 188         return 0;
 189 }
 190
 191 static int meson_ir_remove(struct platform_device *pdev)
 192 {
 193         struct meson_ir *ir = platform_get_drvdata(pdev);
 194         unsigned long flags;
 195
 196         /* Disable the decoder */
 197         spin_lock_irqsave(&ir->lock, flags);
 198         meson_ir_set_mask(ir, IR_DEC_REG1, REG1_ENABLE, 0);
 199         spin_unlock_irqrestore(&ir->lock, flags);
 200
 201         return 0;
 202 }
 203
 204 static void meson_ir_shutdown(struct platform_device *pdev)
 205 {
 206         struct device *dev = &pdev->dev;
 207         struct device_node *node = dev->of_node;
 208         struct meson_ir *ir = platform_get_drvdata(pdev);
 209         unsigned long flags;
 210
 211         spin_lock_irqsave(&ir->lock, flags);
 212
 213         /*
 214          * Set operation mode to NEC/hardware decoding to give
 215          * bootloader a chance to power the system back on
 216          */
 217         if (of_device_is_compatible(node, "amlogic,meson6-ir"))
 218                 meson_ir_set_mask(ir, IR_DEC_REG1, REG1_MODE_MASK,
 219                                   DECODE_MODE_NEC << REG1_MODE_SHIFT);
 220         else
 221                 meson_ir_set_mask(ir, IR_DEC_REG2, REG2_MODE_MASK,
 222                                   DECODE_MODE_NEC << REG2_MODE_SHIFT);
 223
 224         /* Set rate to default value */
 225         meson_ir_set_mask(ir, IR_DEC_REG0, REG0_RATE_MASK, 0x13);
 226
 227         spin_unlock_irqrestore(&ir->lock, flags);
 228 }
 229
 230 static const struct of_device_id meson_ir_match[] = {
 231         { .compatible = "amlogic,meson6-ir" },
 232         { .compatible = "amlogic,meson8b-ir" },
 233         { .compatible = "amlogic,meson-gxbb-ir" },
 234         { },
 235 };
 236 MODULE_DEVICE_TABLE(of, meson_ir_match);
 237
 238 static struct platform_driver meson_ir_driver = {
 239         .probe          = meson_ir_probe,
 240         .remove         = meson_ir_remove,
 241         .shutdown       = meson_ir_shutdown,
 242         .driver = {
 243                 .name           = DRIVER_NAME,
 244                 .of_match_table = meson_ir_match,
 245         },
 246 };
 247
 248 module_platform_driver(meson_ir_driver);
 249
 250 MODULE_DESCRIPTION("Amlogic Meson IR remote receiver driver");
 251 MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
 252 MODULE_LICENSE("GPL v2");