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 }; 34 35 static const struct stm32_sai_conf stm32_sai_conf_h7 = { 36 .version = SAI_STM32H7, 37 }; 38 39 static const struct of_device_id stm32_sai_ids[] = { 40 { .compatible = "st,stm32f4-sai", .data = (void *)&stm32_sai_conf_f4 }, 41 { .compatible = "st,stm32h7-sai", .data = (void *)&stm32_sai_conf_h7 }, 42 {} 43 }; 44 45 static int stm32_sai_sync_conf_client(struct stm32_sai_data *sai, int synci) 46 { 47 int ret; 48 49 /* Enable peripheral clock to allow GCR register access */ 50 ret = clk_prepare_enable(sai->pclk); 51 if (ret) { 52 dev_err(&sai->pdev->dev, "failed to enable clock: %d\n", ret); 53 return ret; 54 } 55 56 writel_relaxed(FIELD_PREP(SAI_GCR_SYNCIN_MASK, (synci - 1)), sai->base); 57 58 clk_disable_unprepare(sai->pclk); 59 60 return 0; 61 } 62 63 static int stm32_sai_sync_conf_provider(struct stm32_sai_data *sai, int synco) 64 { 65 u32 prev_synco; 66 int ret; 67 68 /* Enable peripheral clock to allow GCR register access */ 69 ret = clk_prepare_enable(sai->pclk); 70 if (ret) { 71 dev_err(&sai->pdev->dev, "failed to enable clock: %d\n", ret); 72 return ret; 73 } 74 75 dev_dbg(&sai->pdev->dev, "Set %s%s as synchro provider\n", 76 sai->pdev->dev.of_node->name, 77 synco == STM_SAI_SYNC_OUT_A ? "A" : "B"); 78 79 prev_synco = FIELD_GET(SAI_GCR_SYNCOUT_MASK, readl_relaxed(sai->base)); 80 if (prev_synco != STM_SAI_SYNC_OUT_NONE && synco != prev_synco) { 81 dev_err(&sai->pdev->dev, "%s%s already set as sync provider\n", 82 sai->pdev->dev.of_node->name, 83 prev_synco == STM_SAI_SYNC_OUT_A ? "A" : "B"); 84 clk_disable_unprepare(sai->pclk); 85 return -EINVAL; 86 } 87 88 writel_relaxed(FIELD_PREP(SAI_GCR_SYNCOUT_MASK, synco), sai->base); 89 90 clk_disable_unprepare(sai->pclk); 91 92 return 0; 93 } 94 95 static int stm32_sai_set_sync(struct stm32_sai_data *sai_client, 96 struct device_node *np_provider, 97 int synco, int synci) 98 { 99 struct platform_device *pdev = of_find_device_by_node(np_provider); 100 struct stm32_sai_data *sai_provider; 101 int ret; 102 103 if (!pdev) { 104 dev_err(&sai_client->pdev->dev, 105 "Device not found for node %s\n", np_provider->name); 106 return -ENODEV; 107 } 108 109 sai_provider = platform_get_drvdata(pdev); 110 if (!sai_provider) { 111 dev_err(&sai_client->pdev->dev, 112 "SAI sync provider data not found\n"); 113 return -EINVAL; 114 } 115 116 /* Configure sync client */ 117 ret = stm32_sai_sync_conf_client(sai_client, synci); 118 if (ret < 0) 119 return ret; 120 121 /* Configure sync provider */ 122 return stm32_sai_sync_conf_provider(sai_provider, synco); 123 } 124 125 static int stm32_sai_probe(struct platform_device *pdev) 126 { 127 struct device_node *np = pdev->dev.of_node; 128 struct stm32_sai_data *sai; 129 struct reset_control *rst; 130 struct resource *res; 131 const struct of_device_id *of_id; 132 133 sai = devm_kzalloc(&pdev->dev, sizeof(*sai), GFP_KERNEL); 134 if (!sai) 135 return -ENOMEM; 136 137 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 138 sai->base = devm_ioremap_resource(&pdev->dev, res); 139 if (IS_ERR(sai->base)) 140 return PTR_ERR(sai->base); 141 142 of_id = of_match_device(stm32_sai_ids, &pdev->dev); 143 if (of_id) 144 sai->conf = (struct stm32_sai_conf *)of_id->data; 145 else 146 return -EINVAL; 147 148 if (!STM_SAI_IS_F4(sai)) { 149 sai->pclk = devm_clk_get(&pdev->dev, "pclk"); 150 if (IS_ERR(sai->pclk)) { 151 dev_err(&pdev->dev, "missing bus clock pclk\n"); 152 return PTR_ERR(sai->pclk); 153 } 154 } 155 156 sai->clk_x8k = devm_clk_get(&pdev->dev, "x8k"); 157 if (IS_ERR(sai->clk_x8k)) { 158 dev_err(&pdev->dev, "missing x8k parent clock\n"); 159 return PTR_ERR(sai->clk_x8k); 160 } 161 162 sai->clk_x11k = devm_clk_get(&pdev->dev, "x11k"); 163 if (IS_ERR(sai->clk_x11k)) { 164 dev_err(&pdev->dev, "missing x11k parent clock\n"); 165 return PTR_ERR(sai->clk_x11k); 166 } 167 168 /* init irqs */ 169 sai->irq = platform_get_irq(pdev, 0); 170 if (sai->irq < 0) { 171 dev_err(&pdev->dev, "no irq for node %s\n", pdev->name); 172 return sai->irq; 173 } 174 175 /* reset */ 176 rst = devm_reset_control_get_exclusive(&pdev->dev, NULL); 177 if (!IS_ERR(rst)) { 178 reset_control_assert(rst); 179 udelay(2); 180 reset_control_deassert(rst); 181 } 182 183 sai->pdev = pdev; 184 sai->set_sync = &stm32_sai_set_sync; 185 platform_set_drvdata(pdev, sai); 186 187 return of_platform_populate(np, NULL, NULL, &pdev->dev); 188 } 189 190 static int stm32_sai_remove(struct platform_device *pdev) 191 { 192 of_platform_depopulate(&pdev->dev); 193 194 return 0; 195 } 196 197 MODULE_DEVICE_TABLE(of, stm32_sai_ids); 198 199 static struct platform_driver stm32_sai_driver = { 200 .driver = { 201 .name = "st,stm32-sai", 202 .of_match_table = stm32_sai_ids, 203 }, 204 .probe = stm32_sai_probe, 205 .remove = stm32_sai_remove, 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