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/pinctrl/consumer.h> 25 #include <linux/reset.h> 26 27 #include <sound/dmaengine_pcm.h> 28 #include <sound/core.h> 29 30 #include "stm32_sai.h" 31 32 static const struct stm32_sai_conf stm32_sai_conf_f4 = { 33 .version = SAI_STM32F4, 34 .has_spdif = false, 35 }; 36 37 static const struct stm32_sai_conf stm32_sai_conf_h7 = { 38 .version = SAI_STM32H7, 39 .has_spdif = true, 40 }; 41 42 static const struct of_device_id stm32_sai_ids[] = { 43 { .compatible = "st,stm32f4-sai", .data = (void *)&stm32_sai_conf_f4 }, 44 { .compatible = "st,stm32h7-sai", .data = (void *)&stm32_sai_conf_h7 }, 45 {} 46 }; 47 48 static int stm32_sai_pclk_disable(struct device *dev) 49 { 50 struct stm32_sai_data *sai = dev_get_drvdata(dev); 51 52 clk_disable_unprepare(sai->pclk); 53 54 return 0; 55 } 56 57 static int stm32_sai_pclk_enable(struct device *dev) 58 { 59 struct stm32_sai_data *sai = dev_get_drvdata(dev); 60 int ret; 61 62 ret = clk_prepare_enable(sai->pclk); 63 if (ret) { 64 dev_err(&sai->pdev->dev, "failed to enable clock: %d\n", ret); 65 return ret; 66 } 67 68 return 0; 69 } 70 71 static int stm32_sai_sync_conf_client(struct stm32_sai_data *sai, int synci) 72 { 73 int ret; 74 75 /* Enable peripheral clock to allow GCR register access */ 76 ret = stm32_sai_pclk_enable(&sai->pdev->dev); 77 if (ret) 78 return ret; 79 80 writel_relaxed(FIELD_PREP(SAI_GCR_SYNCIN_MASK, (synci - 1)), sai->base); 81 82 stm32_sai_pclk_disable(&sai->pdev->dev); 83 84 return 0; 85 } 86 87 static int stm32_sai_sync_conf_provider(struct stm32_sai_data *sai, int synco) 88 { 89 u32 prev_synco; 90 int ret; 91 92 /* Enable peripheral clock to allow GCR register access */ 93 ret = stm32_sai_pclk_enable(&sai->pdev->dev); 94 if (ret) 95 return ret; 96 97 dev_dbg(&sai->pdev->dev, "Set %pOFn%s as synchro provider\n", 98 sai->pdev->dev.of_node, 99 synco == STM_SAI_SYNC_OUT_A ? "A" : "B"); 100 101 prev_synco = FIELD_GET(SAI_GCR_SYNCOUT_MASK, readl_relaxed(sai->base)); 102 if (prev_synco != STM_SAI_SYNC_OUT_NONE && synco != prev_synco) { 103 dev_err(&sai->pdev->dev, "%pOFn%s already set as sync provider\n", 104 sai->pdev->dev.of_node, 105 prev_synco == STM_SAI_SYNC_OUT_A ? "A" : "B"); 106 stm32_sai_pclk_disable(&sai->pdev->dev); 107 return -EINVAL; 108 } 109 110 writel_relaxed(FIELD_PREP(SAI_GCR_SYNCOUT_MASK, synco), sai->base); 111 112 stm32_sai_pclk_disable(&sai->pdev->dev); 113 114 return 0; 115 } 116 117 static int stm32_sai_set_sync(struct stm32_sai_data *sai_client, 118 struct device_node *np_provider, 119 int synco, int synci) 120 { 121 struct platform_device *pdev = of_find_device_by_node(np_provider); 122 struct stm32_sai_data *sai_provider; 123 int ret; 124 125 if (!pdev) { 126 dev_err(&sai_client->pdev->dev, 127 "Device not found for node %pOFn\n", np_provider); 128 of_node_put(np_provider); 129 return -ENODEV; 130 } 131 132 sai_provider = platform_get_drvdata(pdev); 133 if (!sai_provider) { 134 dev_err(&sai_client->pdev->dev, 135 "SAI sync provider data not found\n"); 136 ret = -EINVAL; 137 goto error; 138 } 139 140 /* Configure sync client */ 141 ret = stm32_sai_sync_conf_client(sai_client, synci); 142 if (ret < 0) 143 goto error; 144 145 /* Configure sync provider */ 146 ret = stm32_sai_sync_conf_provider(sai_provider, synco); 147 148 error: 149 put_device(&pdev->dev); 150 of_node_put(np_provider); 151 return ret; 152 } 153 154 static int stm32_sai_probe(struct platform_device *pdev) 155 { 156 struct stm32_sai_data *sai; 157 struct reset_control *rst; 158 struct resource *res; 159 const struct of_device_id *of_id; 160 161 sai = devm_kzalloc(&pdev->dev, sizeof(*sai), GFP_KERNEL); 162 if (!sai) 163 return -ENOMEM; 164 165 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 166 sai->base = devm_ioremap_resource(&pdev->dev, res); 167 if (IS_ERR(sai->base)) 168 return PTR_ERR(sai->base); 169 170 of_id = of_match_device(stm32_sai_ids, &pdev->dev); 171 if (of_id) 172 sai->conf = (struct stm32_sai_conf *)of_id->data; 173 else 174 return -EINVAL; 175 176 if (!STM_SAI_IS_F4(sai)) { 177 sai->pclk = devm_clk_get(&pdev->dev, "pclk"); 178 if (IS_ERR(sai->pclk)) { 179 dev_err(&pdev->dev, "missing bus clock pclk\n"); 180 return PTR_ERR(sai->pclk); 181 } 182 } 183 184 sai->clk_x8k = devm_clk_get(&pdev->dev, "x8k"); 185 if (IS_ERR(sai->clk_x8k)) { 186 dev_err(&pdev->dev, "missing x8k parent clock\n"); 187 return PTR_ERR(sai->clk_x8k); 188 } 189 190 sai->clk_x11k = devm_clk_get(&pdev->dev, "x11k"); 191 if (IS_ERR(sai->clk_x11k)) { 192 dev_err(&pdev->dev, "missing x11k parent clock\n"); 193 return PTR_ERR(sai->clk_x11k); 194 } 195 196 /* init irqs */ 197 sai->irq = platform_get_irq(pdev, 0); 198 if (sai->irq < 0) { 199 dev_err(&pdev->dev, "no irq for node %s\n", pdev->name); 200 return sai->irq; 201 } 202 203 /* reset */ 204 rst = devm_reset_control_get_exclusive(&pdev->dev, NULL); 205 if (!IS_ERR(rst)) { 206 reset_control_assert(rst); 207 udelay(2); 208 reset_control_deassert(rst); 209 } 210 211 sai->pdev = pdev; 212 sai->set_sync = &stm32_sai_set_sync; 213 platform_set_drvdata(pdev, sai); 214 215 return devm_of_platform_populate(&pdev->dev); 216 } 217 218 #ifdef CONFIG_PM_SLEEP 219 /* 220 * When pins are shared by two sai sub instances, pins have to be defined 221 * in sai parent node. In this case, pins state is not managed by alsa fw. 222 * These pins are managed in suspend/resume callbacks. 223 */ 224 static int stm32_sai_suspend(struct device *dev) 225 { 226 struct stm32_sai_data *sai = dev_get_drvdata(dev); 227 int ret; 228 229 ret = stm32_sai_pclk_enable(dev); 230 if (ret) 231 return ret; 232 233 sai->gcr = readl_relaxed(sai->base); 234 stm32_sai_pclk_disable(dev); 235 236 return pinctrl_pm_select_sleep_state(dev); 237 } 238 239 static int stm32_sai_resume(struct device *dev) 240 { 241 struct stm32_sai_data *sai = dev_get_drvdata(dev); 242 int ret; 243 244 ret = stm32_sai_pclk_enable(dev); 245 if (ret) 246 return ret; 247 248 writel_relaxed(sai->gcr, sai->base); 249 stm32_sai_pclk_disable(dev); 250 251 return pinctrl_pm_select_default_state(dev); 252 } 253 #endif /* CONFIG_PM_SLEEP */ 254 255 static const struct dev_pm_ops stm32_sai_pm_ops = { 256 SET_SYSTEM_SLEEP_PM_OPS(stm32_sai_suspend, stm32_sai_resume) 257 }; 258 259 MODULE_DEVICE_TABLE(of, stm32_sai_ids); 260 261 static struct platform_driver stm32_sai_driver = { 262 .driver = { 263 .name = "st,stm32-sai", 264 .of_match_table = stm32_sai_ids, 265 .pm = &stm32_sai_pm_ops, 266 }, 267 .probe = stm32_sai_probe, 268 }; 269 270 module_platform_driver(stm32_sai_driver); 271 272 MODULE_DESCRIPTION("STM32 Soc SAI Interface"); 273 MODULE_AUTHOR("Olivier Moysan <olivier.moysan@st.com>"); 274 MODULE_ALIAS("platform:st,stm32-sai"); 275 MODULE_LICENSE("GPL v2"); 276