1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright 2024 NXP 4 */ 5 6 #include <linux/auxiliary_bus.h> 7 #include <linux/device.h> 8 #include <linux/io.h> 9 #include <linux/module.h> 10 #include <linux/of.h> 11 #include <linux/of_address.h> 12 #include <linux/reset-controller.h> 13 14 #define EARC 0x200 15 #define EARC_RESET_MASK 0x3 16 17 struct imx8mp_audiomix_reset { 18 struct reset_controller_dev rcdev; 19 spinlock_t lock; /* protect register read-modify-write cycle */ 20 void __iomem *base; 21 }; 22 23 static struct imx8mp_audiomix_reset *to_imx8mp_audiomix_reset(struct reset_controller_dev *rcdev) 24 { 25 return container_of(rcdev, struct imx8mp_audiomix_reset, rcdev); 26 } 27 28 static int imx8mp_audiomix_reset_assert(struct reset_controller_dev *rcdev, 29 unsigned long id) 30 { 31 struct imx8mp_audiomix_reset *priv = to_imx8mp_audiomix_reset(rcdev); 32 void __iomem *reg_addr = priv->base; 33 unsigned int mask, reg; 34 unsigned long flags; 35 36 mask = BIT(id); 37 spin_lock_irqsave(&priv->lock, flags); 38 reg = readl(reg_addr + EARC); 39 writel(reg & ~mask, reg_addr + EARC); 40 spin_unlock_irqrestore(&priv->lock, flags); 41 42 return 0; 43 } 44 45 static int imx8mp_audiomix_reset_deassert(struct reset_controller_dev *rcdev, 46 unsigned long id) 47 { 48 struct imx8mp_audiomix_reset *priv = to_imx8mp_audiomix_reset(rcdev); 49 void __iomem *reg_addr = priv->base; 50 unsigned int mask, reg; 51 unsigned long flags; 52 53 mask = BIT(id); 54 spin_lock_irqsave(&priv->lock, flags); 55 reg = readl(reg_addr + EARC); 56 writel(reg | mask, reg_addr + EARC); 57 spin_unlock_irqrestore(&priv->lock, flags); 58 59 return 0; 60 } 61 62 static const struct reset_control_ops imx8mp_audiomix_reset_ops = { 63 .assert = imx8mp_audiomix_reset_assert, 64 .deassert = imx8mp_audiomix_reset_deassert, 65 }; 66 67 static int imx8mp_audiomix_reset_probe(struct auxiliary_device *adev, 68 const struct auxiliary_device_id *id) 69 { 70 struct imx8mp_audiomix_reset *priv; 71 struct device *dev = &adev->dev; 72 int ret; 73 74 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 75 if (!priv) 76 return -ENOMEM; 77 78 spin_lock_init(&priv->lock); 79 80 priv->rcdev.owner = THIS_MODULE; 81 priv->rcdev.nr_resets = fls(EARC_RESET_MASK); 82 priv->rcdev.ops = &imx8mp_audiomix_reset_ops; 83 priv->rcdev.of_node = dev->parent->of_node; 84 priv->rcdev.dev = dev; 85 priv->rcdev.of_reset_n_cells = 1; 86 priv->base = of_iomap(dev->parent->of_node, 0); 87 if (!priv->base) 88 return -ENOMEM; 89 90 dev_set_drvdata(dev, priv); 91 92 ret = devm_reset_controller_register(dev, &priv->rcdev); 93 if (ret) 94 goto out_unmap; 95 96 return 0; 97 98 out_unmap: 99 iounmap(priv->base); 100 return ret; 101 } 102 103 static void imx8mp_audiomix_reset_remove(struct auxiliary_device *adev) 104 { 105 struct imx8mp_audiomix_reset *priv = dev_get_drvdata(&adev->dev); 106 107 iounmap(priv->base); 108 } 109 110 static const struct auxiliary_device_id imx8mp_audiomix_reset_ids[] = { 111 { 112 .name = "clk_imx8mp_audiomix.reset", 113 }, 114 { } 115 }; 116 MODULE_DEVICE_TABLE(auxiliary, imx8mp_audiomix_reset_ids); 117 118 static struct auxiliary_driver imx8mp_audiomix_reset_driver = { 119 .probe = imx8mp_audiomix_reset_probe, 120 .remove = imx8mp_audiomix_reset_remove, 121 .id_table = imx8mp_audiomix_reset_ids, 122 }; 123 124 module_auxiliary_driver(imx8mp_audiomix_reset_driver); 125 126 MODULE_AUTHOR("Shengjiu Wang <shengjiu.wang@nxp.com>"); 127 MODULE_DESCRIPTION("Freescale i.MX8MP Audio Block Controller reset driver"); 128 MODULE_LICENSE("GPL"); 129