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

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * ImgTec IR Decoder found in PowerDown Controller.
   4  *
   5  * Copyright 2010-2014 Imagination Technologies Ltd.
   6  *
   7  * This contains core img-ir code for setting up the driver. The two interfaces
   8  * (raw and hardware decode) are handled separately.
   9  */
  10
  11 #include <linux/clk.h>
  12 #include <linux/init.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/io.h>
  15 #include <linux/module.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/slab.h>
  18 #include <linux/spinlock.h>
  19 #include "img-ir.h"
  20
  21 static irqreturn_t img_ir_isr(int irq, void *dev_id)
  22 {
  23         struct img_ir_priv *priv = dev_id;
  24         u32 irq_status;
  25
  26         spin_lock(&priv->lock);
  27         /* we have to clear irqs before reading */
  28         irq_status = img_ir_read(priv, IMG_IR_IRQ_STATUS);
  29         img_ir_write(priv, IMG_IR_IRQ_CLEAR, irq_status);
  30
  31         /* don't handle valid data irqs if we're only interested in matches */
  32         irq_status &= img_ir_read(priv, IMG_IR_IRQ_ENABLE);
  33
  34         /* hand off edge interrupts to raw decode handler */
  35         if (irq_status & IMG_IR_IRQ_EDGE && img_ir_raw_enabled(&priv->raw))
  36                 img_ir_isr_raw(priv, irq_status);
  37
  38         /* hand off hardware match interrupts to hardware decode handler */
  39         if (irq_status & (IMG_IR_IRQ_DATA_MATCH |
  40                           IMG_IR_IRQ_DATA_VALID |
  41                           IMG_IR_IRQ_DATA2_VALID) &&
  42             img_ir_hw_enabled(&priv->hw))
  43                 img_ir_isr_hw(priv, irq_status);
  44
  45         spin_unlock(&priv->lock);
  46         return IRQ_HANDLED;
  47 }
  48
  49 static void img_ir_setup(struct img_ir_priv *priv)
  50 {
  51         /* start off with interrupts disabled */
  52         img_ir_write(priv, IMG_IR_IRQ_ENABLE, 0);
  53
  54         img_ir_setup_raw(priv);
  55         img_ir_setup_hw(priv);
  56
  57         if (!IS_ERR(priv->clk))
  58                 clk_prepare_enable(priv->clk);
  59 }
  60
  61 static void img_ir_ident(struct img_ir_priv *priv)
  62 {
  63         u32 core_rev = img_ir_read(priv, IMG_IR_CORE_REV);
  64
  65         dev_info(priv->dev,
  66                  "IMG IR Decoder (%d.%d.%d.%d) probed successfully\n",
  67                  (core_rev & IMG_IR_DESIGNER) >> IMG_IR_DESIGNER_SHIFT,
  68                  (core_rev & IMG_IR_MAJOR_REV) >> IMG_IR_MAJOR_REV_SHIFT,
  69                  (core_rev & IMG_IR_MINOR_REV) >> IMG_IR_MINOR_REV_SHIFT,
  70                  (core_rev & IMG_IR_MAINT_REV) >> IMG_IR_MAINT_REV_SHIFT);
  71         dev_info(priv->dev, "Modes:%s%s\n",
  72                  img_ir_hw_enabled(&priv->hw) ? " hardware" : "",
  73                  img_ir_raw_enabled(&priv->raw) ? " raw" : "");
  74 }
  75
  76 static int img_ir_probe(struct platform_device *pdev)
  77 {
  78         struct img_ir_priv *priv;
  79         struct resource *res_regs;
  80         int irq, error, error2;
  81
  82         /* Get resources from platform device */
  83         irq = platform_get_irq(pdev, 0);
  84         if (irq < 0) {
  85                 dev_err(&pdev->dev, "cannot find IRQ resource\n");
  86                 return irq;
  87         }
  88
  89         /* Private driver data */
  90         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
  91         if (!priv)
  92                 return -ENOMEM;
  93
  94         platform_set_drvdata(pdev, priv);
  95         priv->dev = &pdev->dev;
  96         spin_lock_init(&priv->lock);
  97
  98         /* Ioremap the registers */
  99         res_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 100         priv->reg_base = devm_ioremap_resource(&pdev->dev, res_regs);
 101         if (IS_ERR(priv->reg_base))
 102                 return PTR_ERR(priv->reg_base);
 103
 104         /* Get core clock */
 105         priv->clk = devm_clk_get(&pdev->dev, "core");
 106         if (IS_ERR(priv->clk))
 107                 dev_warn(&pdev->dev, "cannot get core clock resource\n");
 108
 109         /* Get sys clock */
 110         priv->sys_clk = devm_clk_get(&pdev->dev, "sys");
 111         if (IS_ERR(priv->sys_clk))
 112                 dev_warn(&pdev->dev, "cannot get sys clock resource\n");
 113         /*
 114          * Enabling the system clock before the register interface is
 115          * accessed. ISR shouldn't get called with Sys Clock disabled,
 116          * hence exiting probe with an error.
 117          */
 118         if (!IS_ERR(priv->sys_clk)) {
 119                 error = clk_prepare_enable(priv->sys_clk);
 120                 if (error) {
 121                         dev_err(&pdev->dev, "cannot enable sys clock\n");
 122                         return error;
 123                 }
 124         }
 125
 126         /* Set up raw & hw decoder */
 127         error = img_ir_probe_raw(priv);
 128         error2 = img_ir_probe_hw(priv);
 129         if (error && error2) {
 130                 if (error == -ENODEV)
 131                         error = error2;
 132                 goto err_probe;
 133         }
 134
 135         /* Get the IRQ */
 136         priv->irq = irq;
 137         error = request_irq(priv->irq, img_ir_isr, 0, "img-ir", priv);
 138         if (error) {
 139                 dev_err(&pdev->dev, "cannot register IRQ %u\n",
 140                         priv->irq);
 141                 error = -EIO;
 142                 goto err_irq;
 143         }
 144
 145         img_ir_ident(priv);
 146         img_ir_setup(priv);
 147
 148         return 0;
 149
 150 err_irq:
 151         img_ir_remove_hw(priv);
 152         img_ir_remove_raw(priv);
 153 err_probe:
 154         if (!IS_ERR(priv->sys_clk))
 155                 clk_disable_unprepare(priv->sys_clk);
 156         return error;
 157 }
 158
 159 static int img_ir_remove(struct platform_device *pdev)
 160 {
 161         struct img_ir_priv *priv = platform_get_drvdata(pdev);
 162
 163         free_irq(priv->irq, priv);
 164         img_ir_remove_hw(priv);
 165         img_ir_remove_raw(priv);
 166
 167         if (!IS_ERR(priv->clk))
 168                 clk_disable_unprepare(priv->clk);
 169         if (!IS_ERR(priv->sys_clk))
 170                 clk_disable_unprepare(priv->sys_clk);
 171         return 0;
 172 }
 173
 174 static SIMPLE_DEV_PM_OPS(img_ir_pmops, img_ir_suspend, img_ir_resume);
 175
 176 static const struct of_device_id img_ir_match[] = {
 177         { .compatible = "img,ir-rev1" },
 178         {}
 179 };
 180 MODULE_DEVICE_TABLE(of, img_ir_match);
 181
 182 static struct platform_driver img_ir_driver = {
 183         .driver = {
 184                 .name = "img-ir",
 185                 .of_match_table = img_ir_match,
 186                 .pm = &img_ir_pmops,
 187         },
 188         .probe = img_ir_probe,
 189         .remove = img_ir_remove,
 190 };
 191
 192 module_platform_driver(img_ir_driver);
 193
 194 MODULE_AUTHOR("Imagination Technologies Ltd.");
 195 MODULE_DESCRIPTION("ImgTec IR");
 196 MODULE_LICENSE("GPL");