1 /* 2 * STM32 ALSA SoC Digital Audio Interface (SAI) driver. 3 * 4 * Copyright (C) 2016, STMicroelectronics - All Rights Reserved 5 * Author(s): Olivier Moysan <olivier.moysan@st.com> for STMicroelectronics. 6 * 7 * License terms: GPL V2.0. 8 * 9 * This program is free software; you can redistribute it and/or modify it 10 * under the terms of the GNU General Public License version 2 as published by 11 * the Free Software Foundation. 12 * 13 * This program is distributed in the hope that it will be useful, but 14 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 15 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more 16 * details. 17 */ 18 19 #include <linux/bitfield.h> 20 #include <linux/clk.h> 21 #include <linux/delay.h> 22 #include <linux/module.h> 23 #include <linux/of_platform.h> 24 #include <linux/reset.h> 25 26 #include <sound/dmaengine_pcm.h> 27 #include <sound/core.h> 28 29 #include "stm32_sai.h" 30 31 static const struct stm32_sai_conf stm32_sai_conf_f4 = { 32 .version = SAI_STM32F4, 33 .has_spdif = false, 34 }; 35 36 static const struct stm32_sai_conf stm32_sai_conf_h7 = { 37 .version = SAI_STM32H7, 38 .has_spdif = true, 39 }; 40 41 static const struct of_device_id stm32_sai_ids[] = { 42 { .compatible = "st,stm32f4-sai", .data = (void *)&stm32_sai_conf_f4 }, 43 { .compatible = "st,stm32h7-sai", .data = (void *)&stm32_sai_conf_h7 }, 44 {} 45 }; 46 47 static int stm32_sai_sync_conf_client(struct stm32_sai_data *sai, int synci) 48 { 49 int ret; 50 51 /* Enable peripheral clock to allow GCR register access */ 52 ret = clk_prepare_enable(sai->pclk); 53 if (ret) { 54 dev_err(&sai->pdev->dev, "failed to enable clock: %d\n", ret); 55 return ret; 56 } 57 58 writel_relaxed(FIELD_PREP(SAI_GCR_SYNCIN_MASK, (synci - 1)), sai->base); 59 60 clk_disable_unprepare(sai->pclk); 61 62 return 0; 63 } 64 65 static int stm32_sai_sync_conf_provider(struct stm32_sai_data *sai, int synco) 66 { 67 u32 prev_synco; 68 int ret; 69 70 /* Enable peripheral clock to allow GCR register access */ 71 ret = clk_prepare_enable(sai->pclk); 72 if (ret) { 73 dev_err(&sai->pdev->dev, "failed to enable clock: %d\n", ret); 74 return ret; 75 } 76 77 dev_dbg(&sai->pdev->dev, "Set %pOFn%s as synchro provider\n", 78 sai->pdev->dev.of_node, 79 synco == STM_SAI_SYNC_OUT_A ? "A" : "B"); 80 81 prev_synco = FIELD_GET(SAI_GCR_SYNCOUT_MASK, readl_relaxed(sai->base)); 82 if (prev_synco != STM_SAI_SYNC_OUT_NONE && synco != prev_synco) { 83 dev_err(&sai->pdev->dev, "%pOFn%s already set as sync provider\n", 84 sai->pdev->dev.of_node, 85 prev_synco == STM_SAI_SYNC_OUT_A ? "A" : "B"); 86 clk_disable_unprepare(sai->pclk); 87 return -EINVAL; 88 } 89 90 writel_relaxed(FIELD_PREP(SAI_GCR_SYNCOUT_MASK, synco), sai->base); 91 92 clk_disable_unprepare(sai->pclk); 93 94 return 0; 95 } 96 97 static int stm32_sai_set_sync(struct stm32_sai_data *sai_client, 98 struct device_node *np_provider, 99 int synco, int synci) 100 { 101 struct platform_device *pdev = of_find_device_by_node(np_provider); 102 struct stm32_sai_data *sai_provider; 103 int ret; 104 105 if (!pdev) { 106 dev_err(&sai_client->pdev->dev, 107 "Device not found for node %pOFn\n", np_provider); 108 of_node_put(np_provider); 109 return -ENODEV; 110 } 111 112 sai_provider = platform_get_drvdata(pdev); 113 if (!sai_provider) { 114 dev_err(&sai_client->pdev->dev, 115 "SAI sync provider data not found\n"); 116 ret = -EINVAL; 117 goto error; 118 } 119 120 /* Configure sync client */ 121 ret = stm32_sai_sync_conf_client(sai_client, synci); 122 if (ret < 0) 123 goto error; 124 125 /* Configure sync provider */ 126 ret = stm32_sai_sync_conf_provider(sai_provider, synco); 127 128 error: 129 put_device(&pdev->dev); 130 of_node_put(np_provider); 131 return ret; 132 } 133 134 static int stm32_sai_probe(struct platform_device *pdev) 135 { 136 struct stm32_sai_data *sai; 137 struct reset_control *rst; 138 struct resource *res; 139 const struct of_device_id *of_id; 140 141 sai = devm_kzalloc(&pdev->dev, sizeof(*sai), GFP_KERNEL); 142 if (!sai) 143 return -ENOMEM; 144 145 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 146 sai->base = devm_ioremap_resource(&pdev->dev, res); 147 if (IS_ERR(sai->base)) 148 return PTR_ERR(sai->base); 149 150 of_id = of_match_device(stm32_sai_ids, &pdev->dev); 151 if (of_id) 152 sai->conf = (struct stm32_sai_conf *)of_id->data; 153 else 154 return -EINVAL; 155 156 if (!STM_SAI_IS_F4(sai)) { 157 sai->pclk = devm_clk_get(&pdev->dev, "pclk"); 158 if (IS_ERR(sai->pclk)) { 159 dev_err(&pdev->dev, "missing bus clock pclk\n"); 160 return PTR_ERR(sai->pclk); 161 } 162 } 163 164 sai->clk_x8k = devm_clk_get(&pdev->dev, "x8k"); 165 if (IS_ERR(sai->clk_x8k)) { 166 dev_err(&pdev->dev, "missing x8k parent clock\n"); 167 return PTR_ERR(sai->clk_x8k); 168 } 169 170 sai->clk_x11k = devm_clk_get(&pdev->dev, "x11k"); 171 if (IS_ERR(sai->clk_x11k)) { 172 dev_err(&pdev->dev, "missing x11k parent clock\n"); 173 return PTR_ERR(sai->clk_x11k); 174 } 175 176 /* init irqs */ 177 sai->irq = platform_get_irq(pdev, 0); 178 if (sai->irq < 0) { 179 dev_err(&pdev->dev, "no irq for node %s\n", pdev->name); 180 return sai->irq; 181 } 182 183 /* reset */ 184 rst = devm_reset_control_get_exclusive(&pdev->dev, NULL); 185 if (!IS_ERR(rst)) { 186 reset_control_assert(rst); 187 udelay(2); 188 reset_control_deassert(rst); 189 } 190 191 sai->pdev = pdev; 192 sai->set_sync = &stm32_sai_set_sync; 193 platform_set_drvdata(pdev, sai); 194 195 return devm_of_platform_populate(&pdev->dev); 196 } 197 198 MODULE_DEVICE_TABLE(of, stm32_sai_ids); 199 200 static struct platform_driver stm32_sai_driver = { 201 .driver = { 202 .name = "st,stm32-sai", 203 .of_match_table = stm32_sai_ids, 204 }, 205 .probe = stm32_sai_probe, 206 }; 207 208 module_platform_driver(stm32_sai_driver); 209 210 MODULE_DESCRIPTION("STM32 Soc SAI Interface"); 211 MODULE_AUTHOR("Olivier Moysan <olivier.moysan@st.com>"); 212 MODULE_ALIAS("platform:st,stm32-sai"); 213 MODULE_LICENSE("GPL v2"); 214