linux/drivers/media/rc/meson-ir.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Driver for Amlogic Meson IR remote receiver
   4 *
   5 * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com>
   6 */
   7
   8#include <linux/device.h>
   9#include <linux/err.h>
  10#include <linux/interrupt.h>
  11#include <linux/io.h>
  12#include <linux/module.h>
  13#include <linux/of_platform.h>
  14#include <linux/platform_device.h>
  15#include <linux/spinlock.h>
  16#include <linux/bitfield.h>
  17
  18#include <media/rc-core.h>
  19
  20#define DRIVER_NAME             "meson-ir"
  21
  22/* valid on all Meson platforms */
  23#define IR_DEC_LDR_ACTIVE       0x00
  24#define IR_DEC_LDR_IDLE         0x04
  25#define IR_DEC_LDR_REPEAT       0x08
  26#define IR_DEC_BIT_0            0x0c
  27#define IR_DEC_REG0             0x10
  28#define IR_DEC_FRAME            0x14
  29#define IR_DEC_STATUS           0x18
  30#define IR_DEC_REG1             0x1c
  31/* only available on Meson 8b and newer */
  32#define IR_DEC_REG2             0x20
  33
  34#define REG0_RATE_MASK          GENMASK(11, 0)
  35
  36#define DECODE_MODE_NEC         0x0
  37#define DECODE_MODE_RAW         0x2
  38
  39/* Meson 6b uses REG1 to configure the mode */
  40#define REG1_MODE_MASK          GENMASK(8, 7)
  41#define REG1_MODE_SHIFT         7
  42
  43/* Meson 8b / GXBB use REG2 to configure the mode */
  44#define REG2_MODE_MASK          GENMASK(3, 0)
  45#define REG2_MODE_SHIFT         0
  46
  47#define REG1_TIME_IV_MASK       GENMASK(28, 16)
  48
  49#define REG1_IRQSEL_MASK        GENMASK(3, 2)
  50#define REG1_IRQSEL_NEC_MODE    0
  51#define REG1_IRQSEL_RISE_FALL   1
  52#define REG1_IRQSEL_FALL        2
  53#define REG1_IRQSEL_RISE        3
  54
  55#define REG1_RESET              BIT(0)
  56#define REG1_ENABLE             BIT(15)
  57
  58#define STATUS_IR_DEC_IN        BIT(8)
  59
  60#define MESON_TRATE             10      /* us */
  61
  62struct meson_ir {
  63        void __iomem    *reg;
  64        struct rc_dev   *rc;
  65        spinlock_t      lock;
  66};
  67
  68static void meson_ir_set_mask(struct meson_ir *ir, unsigned int reg,
  69                              u32 mask, u32 value)
  70{
  71        u32 data;
  72
  73        data = readl(ir->reg + reg);
  74        data &= ~mask;
  75        data |= (value & mask);
  76        writel(data, ir->reg + reg);
  77}
  78
  79static irqreturn_t meson_ir_irq(int irqno, void *dev_id)
  80{
  81        struct meson_ir *ir = dev_id;
  82        u32 duration, status;
  83        struct ir_raw_event rawir = {};
  84
  85        spin_lock(&ir->lock);
  86
  87        duration = readl_relaxed(ir->reg + IR_DEC_REG1);
  88        duration = FIELD_GET(REG1_TIME_IV_MASK, duration);
  89        rawir.duration = duration * MESON_TRATE;
  90
  91        status = readl_relaxed(ir->reg + IR_DEC_STATUS);
  92        rawir.pulse = !!(status & STATUS_IR_DEC_IN);
  93
  94        ir_raw_event_store_with_timeout(ir->rc, &rawir);
  95
  96        spin_unlock(&ir->lock);
  97
  98        return IRQ_HANDLED;
  99}
 100
 101static int meson_ir_probe(struct platform_device *pdev)
 102{
 103        struct device *dev = &pdev->dev;
 104        struct device_node *node = dev->of_node;
 105        struct resource *res;
 106        const char *map_name;
 107        struct meson_ir *ir;
 108        int irq, ret;
 109
 110        ir = devm_kzalloc(dev, sizeof(struct meson_ir), GFP_KERNEL);
 111        if (!ir)
 112                return -ENOMEM;
 113
 114        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 115        ir->reg = devm_ioremap_resource(dev, res);
 116        if (IS_ERR(ir->reg))
 117                return PTR_ERR(ir->reg);
 118
 119        irq = platform_get_irq(pdev, 0);
 120        if (irq < 0)
 121                return irq;
 122
 123        ir->rc = devm_rc_allocate_device(dev, RC_DRIVER_IR_RAW);
 124        if (!ir->rc) {
 125                dev_err(dev, "failed to allocate rc device\n");
 126                return -ENOMEM;
 127        }
 128
 129        ir->rc->priv = ir;
 130        ir->rc->device_name = DRIVER_NAME;
 131        ir->rc->input_phys = DRIVER_NAME "/input0";
 132        ir->rc->input_id.bustype = BUS_HOST;
 133        map_name = of_get_property(node, "linux,rc-map-name", NULL);
 134        ir->rc->map_name = map_name ? map_name : RC_MAP_EMPTY;
 135        ir->rc->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
 136        ir->rc->rx_resolution = MESON_TRATE;
 137        ir->rc->min_timeout = 1;
 138        ir->rc->timeout = IR_DEFAULT_TIMEOUT;
 139        ir->rc->max_timeout = 10 * IR_DEFAULT_TIMEOUT;
 140        ir->rc->driver_name = DRIVER_NAME;
 141
 142        spin_lock_init(&ir->lock);
 143        platform_set_drvdata(pdev, ir);
 144
 145        ret = devm_rc_register_device(dev, ir->rc);
 146        if (ret) {
 147                dev_err(dev, "failed to register rc device\n");
 148                return ret;
 149        }
 150
 151        ret = devm_request_irq(dev, irq, meson_ir_irq, 0, NULL, ir);
 152        if (ret) {
 153                dev_err(dev, "failed to request irq\n");
 154                return ret;
 155        }
 156
 157        /* Reset the decoder */
 158        meson_ir_set_mask(ir, IR_DEC_REG1, REG1_RESET, REG1_RESET);
 159        meson_ir_set_mask(ir, IR_DEC_REG1, REG1_RESET, 0);
 160
 161        /* Set general operation mode (= raw/software decoding) */
 162        if (of_device_is_compatible(node, "amlogic,meson6-ir"))
 163                meson_ir_set_mask(ir, IR_DEC_REG1, REG1_MODE_MASK,
 164                                  FIELD_PREP(REG1_MODE_MASK, DECODE_MODE_RAW));
 165        else
 166                meson_ir_set_mask(ir, IR_DEC_REG2, REG2_MODE_MASK,
 167                                  FIELD_PREP(REG2_MODE_MASK, DECODE_MODE_RAW));
 168
 169        /* Set rate */
 170        meson_ir_set_mask(ir, IR_DEC_REG0, REG0_RATE_MASK, MESON_TRATE - 1);
 171        /* IRQ on rising and falling edges */
 172        meson_ir_set_mask(ir, IR_DEC_REG1, REG1_IRQSEL_MASK,
 173                          FIELD_PREP(REG1_IRQSEL_MASK, REG1_IRQSEL_RISE_FALL));
 174        /* Enable the decoder */
 175        meson_ir_set_mask(ir, IR_DEC_REG1, REG1_ENABLE, REG1_ENABLE);
 176
 177        dev_info(dev, "receiver initialized\n");
 178
 179        return 0;
 180}
 181
 182static int meson_ir_remove(struct platform_device *pdev)
 183{
 184        struct meson_ir *ir = platform_get_drvdata(pdev);
 185        unsigned long flags;
 186
 187        /* Disable the decoder */
 188        spin_lock_irqsave(&ir->lock, flags);
 189        meson_ir_set_mask(ir, IR_DEC_REG1, REG1_ENABLE, 0);
 190        spin_unlock_irqrestore(&ir->lock, flags);
 191
 192        return 0;
 193}
 194
 195static void meson_ir_shutdown(struct platform_device *pdev)
 196{
 197        struct device *dev = &pdev->dev;
 198        struct device_node *node = dev->of_node;
 199        struct meson_ir *ir = platform_get_drvdata(pdev);
 200        unsigned long flags;
 201
 202        spin_lock_irqsave(&ir->lock, flags);
 203
 204        /*
 205         * Set operation mode to NEC/hardware decoding to give
 206         * bootloader a chance to power the system back on
 207         */
 208        if (of_device_is_compatible(node, "amlogic,meson6-ir"))
 209                meson_ir_set_mask(ir, IR_DEC_REG1, REG1_MODE_MASK,
 210                                  DECODE_MODE_NEC << REG1_MODE_SHIFT);
 211        else
 212                meson_ir_set_mask(ir, IR_DEC_REG2, REG2_MODE_MASK,
 213                                  DECODE_MODE_NEC << REG2_MODE_SHIFT);
 214
 215        /* Set rate to default value */
 216        meson_ir_set_mask(ir, IR_DEC_REG0, REG0_RATE_MASK, 0x13);
 217
 218        spin_unlock_irqrestore(&ir->lock, flags);
 219}
 220
 221static const struct of_device_id meson_ir_match[] = {
 222        { .compatible = "amlogic,meson6-ir" },
 223        { .compatible = "amlogic,meson8b-ir" },
 224        { .compatible = "amlogic,meson-gxbb-ir" },
 225        { },
 226};
 227MODULE_DEVICE_TABLE(of, meson_ir_match);
 228
 229static struct platform_driver meson_ir_driver = {
 230        .probe          = meson_ir_probe,
 231        .remove         = meson_ir_remove,
 232        .shutdown       = meson_ir_shutdown,
 233        .driver = {
 234                .name           = DRIVER_NAME,
 235                .of_match_table = meson_ir_match,
 236        },
 237};
 238
 239module_platform_driver(meson_ir_driver);
 240
 241MODULE_DESCRIPTION("Amlogic Meson IR remote receiver driver");
 242MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
 243MODULE_LICENSE("GPL v2");
 244