drivers/media/rc/img-ir/img-ir-core.c

   1 /*
   2  * ImgTec IR Decoder found in PowerDown Controller.
   3  *
   4  * Copyright 2010-2014 Imagination Technologies Ltd.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by the
   8  * Free Software Foundation; either version 2 of the License, or (at your
   9  * option) any later version.
  10  *
  11  * This contains core img-ir code for setting up the driver. The two interfaces
  12  * (raw and hardware decode) are handled separately.
  13  */
  14
  15 #include <linux/clk.h>
  16 #include <linux/init.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/io.h>
  19 #include <linux/module.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/slab.h>
  22 #include <linux/spinlock.h>
  23 #include "img-ir.h"
  24
  25 static irqreturn_t img_ir_isr(int irq, void *dev_id)
  26 {
  27         struct img_ir_priv *priv = dev_id;
  28         u32 irq_status;
  29
  30         spin_lock(&priv->lock);
  31         /* we have to clear irqs before reading */
  32         irq_status = img_ir_read(priv, IMG_IR_IRQ_STATUS);
  33         img_ir_write(priv, IMG_IR_IRQ_CLEAR, irq_status);
  34
  35         /* don't handle valid data irqs if we're only interested in matches */
  36         irq_status &= img_ir_read(priv, IMG_IR_IRQ_ENABLE);
  37
  38         /* hand off edge interrupts to raw decode handler */
  39         if (irq_status & IMG_IR_IRQ_EDGE && img_ir_raw_enabled(&priv->raw))
  40                 img_ir_isr_raw(priv, irq_status);
  41
  42         /* hand off hardware match interrupts to hardware decode handler */
  43         if (irq_status & (IMG_IR_IRQ_DATA_MATCH |
  44                           IMG_IR_IRQ_DATA_VALID |
  45                           IMG_IR_IRQ_DATA2_VALID) &&
  46             img_ir_hw_enabled(&priv->hw))
  47                 img_ir_isr_hw(priv, irq_status);
  48
  49         spin_unlock(&priv->lock);
  50         return IRQ_HANDLED;
  51 }
  52
  53 static void img_ir_setup(struct img_ir_priv *priv)
  54 {
  55         /* start off with interrupts disabled */
  56         img_ir_write(priv, IMG_IR_IRQ_ENABLE, 0);
  57
  58         img_ir_setup_raw(priv);
  59         img_ir_setup_hw(priv);
  60
  61         if (!IS_ERR(priv->clk))
  62                 clk_prepare_enable(priv->clk);
  63 }
  64
  65 static void img_ir_ident(struct img_ir_priv *priv)
  66 {
  67         u32 core_rev = img_ir_read(priv, IMG_IR_CORE_REV);
  68
  69         dev_info(priv->dev,
  70                  "IMG IR Decoder (%d.%d.%d.%d) probed successfully\n",
  71                  (core_rev & IMG_IR_DESIGNER) >> IMG_IR_DESIGNER_SHIFT,
  72                  (core_rev & IMG_IR_MAJOR_REV) >> IMG_IR_MAJOR_REV_SHIFT,
  73                  (core_rev & IMG_IR_MINOR_REV) >> IMG_IR_MINOR_REV_SHIFT,
  74                  (core_rev & IMG_IR_MAINT_REV) >> IMG_IR_MAINT_REV_SHIFT);
  75         dev_info(priv->dev, "Modes:%s%s\n",
  76                  img_ir_hw_enabled(&priv->hw) ? " hardware" : "",
  77                  img_ir_raw_enabled(&priv->raw) ? " raw" : "");
  78 }
  79
  80 static int img_ir_probe(struct platform_device *pdev)
  81 {
  82         struct img_ir_priv *priv;
  83         struct resource *res_regs;
  84         int irq, error, error2;
  85
  86         /* Get resources from platform device */
  87         irq = platform_get_irq(pdev, 0);
  88         if (irq < 0) {
  89                 dev_err(&pdev->dev, "cannot find IRQ resource\n");
  90                 return irq;
  91         }
  92
  93         /* Private driver data */
  94         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
  95         if (!priv)
  96                 return -ENOMEM;
  97
  98         platform_set_drvdata(pdev, priv);
  99         priv->dev = &pdev->dev;
 100         spin_lock_init(&priv->lock);
 101
 102         /* Ioremap the registers */
 103         res_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 104         priv->reg_base = devm_ioremap_resource(&pdev->dev, res_regs);
 105         if (IS_ERR(priv->reg_base))
 106                 return PTR_ERR(priv->reg_base);
 107
 108         /* Get core clock */
 109         priv->clk = devm_clk_get(&pdev->dev, "core");
 110         if (IS_ERR(priv->clk))
 111                 dev_warn(&pdev->dev, "cannot get core clock resource\n");
 112
 113         /* Get sys clock */
 114         priv->sys_clk = devm_clk_get(&pdev->dev, "sys");
 115         if (IS_ERR(priv->sys_clk))
 116                 dev_warn(&pdev->dev, "cannot get sys clock resource\n");
 117         /*
 118          * Enabling the system clock before the register interface is
 119          * accessed. ISR shouldn't get called with Sys Clock disabled,
 120          * hence exiting probe with an error.
 121          */
 122         if (!IS_ERR(priv->sys_clk)) {
 123                 error = clk_prepare_enable(priv->sys_clk);
 124                 if (error) {
 125                         dev_err(&pdev->dev, "cannot enable sys clock\n");
 126                         return error;
 127                 }
 128         }
 129
 130         /* Set up raw & hw decoder */
 131         error = img_ir_probe_raw(priv);
 132         error2 = img_ir_probe_hw(priv);
 133         if (error && error2) {
 134                 if (error == -ENODEV)
 135                         error = error2;
 136                 goto err_probe;
 137         }
 138
 139         /* Get the IRQ */
 140         priv->irq = irq;
 141         error = request_irq(priv->irq, img_ir_isr, 0, "img-ir", priv);
 142         if (error) {
 143                 dev_err(&pdev->dev, "cannot register IRQ %u\n",
 144                         priv->irq);
 145                 error = -EIO;
 146                 goto err_irq;
 147         }
 148
 149         img_ir_ident(priv);
 150         img_ir_setup(priv);
 151
 152         return 0;
 153
 154 err_irq:
 155         img_ir_remove_hw(priv);
 156         img_ir_remove_raw(priv);
 157 err_probe:
 158         if (!IS_ERR(priv->sys_clk))
 159                 clk_disable_unprepare(priv->sys_clk);
 160         return error;
 161 }
 162
 163 static int img_ir_remove(struct platform_device *pdev)
 164 {
 165         struct img_ir_priv *priv = platform_get_drvdata(pdev);
 166
 167         free_irq(priv->irq, priv);
 168         img_ir_remove_hw(priv);
 169         img_ir_remove_raw(priv);
 170
 171         if (!IS_ERR(priv->clk))
 172                 clk_disable_unprepare(priv->clk);
 173         if (!IS_ERR(priv->sys_clk))
 174                 clk_disable_unprepare(priv->sys_clk);
 175         return 0;
 176 }
 177
 178 static SIMPLE_DEV_PM_OPS(img_ir_pmops, img_ir_suspend, img_ir_resume);
 179
 180 static const struct of_device_id img_ir_match[] = {
 181         { .compatible = "img,ir-rev1" },
 182         {}
 183 };
 184 MODULE_DEVICE_TABLE(of, img_ir_match);
 185
 186 static struct platform_driver img_ir_driver = {
 187         .driver = {
 188                 .name = "img-ir",
 189                 .of_match_table = img_ir_match,
 190                 .pm = &img_ir_pmops,
 191         },
 192         .probe = img_ir_probe,
 193         .remove = img_ir_remove,
 194 };
 195
 196 module_platform_driver(img_ir_driver);
 197
 198 MODULE_AUTHOR("Imagination Technologies Ltd.");
 199 MODULE_DESCRIPTION("ImgTec IR");
 200 MODULE_LICENSE("GPL");