1 // SPDX-License-Identifier: (GPL-2.0 OR MIT) 2 // Copyright (c) 2018 BayLibre, SAS. 3 // Author: Jerome Brunet <jbrunet@baylibre.com> 4 5 #include <linux/clk.h> 6 #include <linux/io.h> 7 #include <linux/module.h> 8 #include <linux/of.h> 9 #include <linux/platform_device.h> 10 #include <linux/reset-controller.h> 11 #include <linux/spinlock.h> 12 13 #include <dt-bindings/reset/amlogic,meson-axg-audio-arb.h> 14 15 struct meson_audio_arb_data { 16 struct reset_controller_dev rstc; 17 void __iomem *regs; 18 struct clk *clk; 19 const unsigned int *reset_bits; 20 spinlock_t lock; 21 }; 22 23 struct meson_audio_arb_match_data { 24 const unsigned int *reset_bits; 25 unsigned int reset_num; 26 }; 27 28 #define ARB_GENERAL_BIT 31 29 30 static const unsigned int axg_audio_arb_reset_bits[] = { 31 [AXG_ARB_TODDR_A] = 0, 32 [AXG_ARB_TODDR_B] = 1, 33 [AXG_ARB_TODDR_C] = 2, 34 [AXG_ARB_FRDDR_A] = 4, 35 [AXG_ARB_FRDDR_B] = 5, 36 [AXG_ARB_FRDDR_C] = 6, 37 }; 38 39 static const struct meson_audio_arb_match_data axg_audio_arb_match = { 40 .reset_bits = axg_audio_arb_reset_bits, 41 .reset_num = ARRAY_SIZE(axg_audio_arb_reset_bits), 42 }; 43 44 static const unsigned int sm1_audio_arb_reset_bits[] = { 45 [AXG_ARB_TODDR_A] = 0, 46 [AXG_ARB_TODDR_B] = 1, 47 [AXG_ARB_TODDR_C] = 2, 48 [AXG_ARB_FRDDR_A] = 4, 49 [AXG_ARB_FRDDR_B] = 5, 50 [AXG_ARB_FRDDR_C] = 6, 51 [AXG_ARB_TODDR_D] = 3, 52 [AXG_ARB_FRDDR_D] = 7, 53 }; 54 55 static const struct meson_audio_arb_match_data sm1_audio_arb_match = { 56 .reset_bits = sm1_audio_arb_reset_bits, 57 .reset_num = ARRAY_SIZE(sm1_audio_arb_reset_bits), 58 }; 59 60 static int meson_audio_arb_update(struct reset_controller_dev *rcdev, 61 unsigned long id, bool assert) 62 { 63 u32 val; 64 struct meson_audio_arb_data *arb = 65 container_of(rcdev, struct meson_audio_arb_data, rstc); 66 67 spin_lock(&arb->lock); 68 val = readl(arb->regs); 69 70 if (assert) 71 val &= ~BIT(arb->reset_bits[id]); 72 else 73 val |= BIT(arb->reset_bits[id]); 74 75 writel(val, arb->regs); 76 spin_unlock(&arb->lock); 77 78 return 0; 79 } 80 81 static int meson_audio_arb_status(struct reset_controller_dev *rcdev, 82 unsigned long id) 83 { 84 u32 val; 85 struct meson_audio_arb_data *arb = 86 container_of(rcdev, struct meson_audio_arb_data, rstc); 87 88 val = readl(arb->regs); 89 90 return !(val & BIT(arb->reset_bits[id])); 91 } 92 93 static int meson_audio_arb_assert(struct reset_controller_dev *rcdev, 94 unsigned long id) 95 { 96 return meson_audio_arb_update(rcdev, id, true); 97 } 98 99 static int meson_audio_arb_deassert(struct reset_controller_dev *rcdev, 100 unsigned long id) 101 { 102 return meson_audio_arb_update(rcdev, id, false); 103 } 104 105 static const struct reset_control_ops meson_audio_arb_rstc_ops = { 106 .assert = meson_audio_arb_assert, 107 .deassert = meson_audio_arb_deassert, 108 .status = meson_audio_arb_status, 109 }; 110 111 static const struct of_device_id meson_audio_arb_of_match[] = { 112 { 113 .compatible = "amlogic,meson-axg-audio-arb", 114 .data = &axg_audio_arb_match, 115 }, { 116 .compatible = "amlogic,meson-sm1-audio-arb", 117 .data = &sm1_audio_arb_match, 118 }, 119 {} 120 }; 121 MODULE_DEVICE_TABLE(of, meson_audio_arb_of_match); 122 123 static int meson_audio_arb_remove(struct platform_device *pdev) 124 { 125 struct meson_audio_arb_data *arb = platform_get_drvdata(pdev); 126 127 /* Disable all access */ 128 spin_lock(&arb->lock); 129 writel(0, arb->regs); 130 spin_unlock(&arb->lock); 131 132 clk_disable_unprepare(arb->clk); 133 134 return 0; 135 } 136 137 static int meson_audio_arb_probe(struct platform_device *pdev) 138 { 139 struct device *dev = &pdev->dev; 140 const struct meson_audio_arb_match_data *data; 141 struct meson_audio_arb_data *arb; 142 struct resource *res; 143 int ret; 144 145 data = of_device_get_match_data(dev); 146 if (!data) 147 return -EINVAL; 148 149 arb = devm_kzalloc(dev, sizeof(*arb), GFP_KERNEL); 150 if (!arb) 151 return -ENOMEM; 152 platform_set_drvdata(pdev, arb); 153 154 arb->clk = devm_clk_get(dev, NULL); 155 if (IS_ERR(arb->clk)) 156 return dev_err_probe(dev, PTR_ERR(arb->clk), "failed to get clock\n"); 157 158 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 159 arb->regs = devm_ioremap_resource(dev, res); 160 if (IS_ERR(arb->regs)) 161 return PTR_ERR(arb->regs); 162 163 spin_lock_init(&arb->lock); 164 arb->reset_bits = data->reset_bits; 165 arb->rstc.nr_resets = data->reset_num; 166 arb->rstc.ops = &meson_audio_arb_rstc_ops; 167 arb->rstc.of_node = dev->of_node; 168 arb->rstc.owner = THIS_MODULE; 169 170 /* 171 * Enable general : 172 * In the initial state, all memory interfaces are disabled 173 * and the general bit is on 174 */ 175 ret = clk_prepare_enable(arb->clk); 176 if (ret) { 177 dev_err(dev, "failed to enable arb clock\n"); 178 return ret; 179 } 180 writel(BIT(ARB_GENERAL_BIT), arb->regs); 181 182 /* Register reset controller */ 183 ret = devm_reset_controller_register(dev, &arb->rstc); 184 if (ret) { 185 dev_err(dev, "failed to register arb reset controller\n"); 186 meson_audio_arb_remove(pdev); 187 } 188 189 return ret; 190 } 191 192 static struct platform_driver meson_audio_arb_pdrv = { 193 .probe = meson_audio_arb_probe, 194 .remove = meson_audio_arb_remove, 195 .driver = { 196 .name = "meson-audio-arb-reset", 197 .of_match_table = meson_audio_arb_of_match, 198 }, 199 }; 200 module_platform_driver(meson_audio_arb_pdrv); 201 202 MODULE_DESCRIPTION("Amlogic A113 Audio Memory Arbiter"); 203 MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>"); 204 MODULE_LICENSE("GPL v2"); 205