sound/soc/stm/stm32_sai.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * STM32 ALSA SoC Digital Audio Interface (SAI) driver.
   4  *
   5  * Copyright (C) 2016, STMicroelectronics - All Rights Reserved
   6  * Author(s): Olivier Moysan <olivier.moysan@st.com> for STMicroelectronics.
   7  */
   8
   9 #include <linux/bitfield.h>
  10 #include <linux/clk.h>
  11 #include <linux/delay.h>
  12 #include <linux/module.h>
  13 #include <linux/of_platform.h>
  14 #include <linux/pinctrl/consumer.h>
  15 #include <linux/reset.h>
  16
  17 #include <sound/dmaengine_pcm.h>
  18 #include <sound/core.h>
  19
  20 #include "stm32_sai.h"
  21
  22 static const struct stm32_sai_conf stm32_sai_conf_f4 = {
  23         .version = SAI_STM32F4,
  24         .has_spdif = false,
  25 };
  26
  27 static const struct stm32_sai_conf stm32_sai_conf_h7 = {
  28         .version = SAI_STM32H7,
  29         .has_spdif = true,
  30 };
  31
  32 static const struct of_device_id stm32_sai_ids[] = {
  33         { .compatible = "st,stm32f4-sai", .data = (void *)&stm32_sai_conf_f4 },
  34         { .compatible = "st,stm32h7-sai", .data = (void *)&stm32_sai_conf_h7 },
  35         {}
  36 };
  37
  38 static int stm32_sai_pclk_disable(struct device *dev)
  39 {
  40         struct stm32_sai_data *sai = dev_get_drvdata(dev);
  41
  42         clk_disable_unprepare(sai->pclk);
  43
  44         return 0;
  45 }
  46
  47 static int stm32_sai_pclk_enable(struct device *dev)
  48 {
  49         struct stm32_sai_data *sai = dev_get_drvdata(dev);
  50         int ret;
  51
  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         return 0;
  59 }
  60
  61 static int stm32_sai_sync_conf_client(struct stm32_sai_data *sai, int synci)
  62 {
  63         int ret;
  64
  65         /* Enable peripheral clock to allow GCR register access */
  66         ret = stm32_sai_pclk_enable(&sai->pdev->dev);
  67         if (ret)
  68                 return ret;
  69
  70         writel_relaxed(FIELD_PREP(SAI_GCR_SYNCIN_MASK, (synci - 1)), sai->base);
  71
  72         stm32_sai_pclk_disable(&sai->pdev->dev);
  73
  74         return 0;
  75 }
  76
  77 static int stm32_sai_sync_conf_provider(struct stm32_sai_data *sai, int synco)
  78 {
  79         u32 prev_synco;
  80         int ret;
  81
  82         /* Enable peripheral clock to allow GCR register access */
  83         ret = stm32_sai_pclk_enable(&sai->pdev->dev);
  84         if (ret)
  85                 return ret;
  86
  87         dev_dbg(&sai->pdev->dev, "Set %pOFn%s as synchro provider\n",
  88                 sai->pdev->dev.of_node,
  89                 synco == STM_SAI_SYNC_OUT_A ? "A" : "B");
  90
  91         prev_synco = FIELD_GET(SAI_GCR_SYNCOUT_MASK, readl_relaxed(sai->base));
  92         if (prev_synco != STM_SAI_SYNC_OUT_NONE && synco != prev_synco) {
  93                 dev_err(&sai->pdev->dev, "%pOFn%s already set as sync provider\n",
  94                         sai->pdev->dev.of_node,
  95                         prev_synco == STM_SAI_SYNC_OUT_A ? "A" : "B");
  96                         stm32_sai_pclk_disable(&sai->pdev->dev);
  97                 return -EINVAL;
  98         }
  99
 100         writel_relaxed(FIELD_PREP(SAI_GCR_SYNCOUT_MASK, synco), sai->base);
 101
 102         stm32_sai_pclk_disable(&sai->pdev->dev);
 103
 104         return 0;
 105 }
 106
 107 static int stm32_sai_set_sync(struct stm32_sai_data *sai_client,
 108                               struct device_node *np_provider,
 109                               int synco, int synci)
 110 {
 111         struct platform_device *pdev = of_find_device_by_node(np_provider);
 112         struct stm32_sai_data *sai_provider;
 113         int ret;
 114
 115         if (!pdev) {
 116                 dev_err(&sai_client->pdev->dev,
 117                         "Device not found for node %pOFn\n", np_provider);
 118                 of_node_put(np_provider);
 119                 return -ENODEV;
 120         }
 121
 122         sai_provider = platform_get_drvdata(pdev);
 123         if (!sai_provider) {
 124                 dev_err(&sai_client->pdev->dev,
 125                         "SAI sync provider data not found\n");
 126                 ret = -EINVAL;
 127                 goto error;
 128         }
 129
 130         /* Configure sync client */
 131         ret = stm32_sai_sync_conf_client(sai_client, synci);
 132         if (ret < 0)
 133                 goto error;
 134
 135         /* Configure sync provider */
 136         ret = stm32_sai_sync_conf_provider(sai_provider, synco);
 137
 138 error:
 139         put_device(&pdev->dev);
 140         of_node_put(np_provider);
 141         return ret;
 142 }
 143
 144 static int stm32_sai_probe(struct platform_device *pdev)
 145 {
 146         struct stm32_sai_data *sai;
 147         struct reset_control *rst;
 148         struct resource *res;
 149         const struct of_device_id *of_id;
 150
 151         sai = devm_kzalloc(&pdev->dev, sizeof(*sai), GFP_KERNEL);
 152         if (!sai)
 153                 return -ENOMEM;
 154
 155         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 156         sai->base = devm_ioremap_resource(&pdev->dev, res);
 157         if (IS_ERR(sai->base))
 158                 return PTR_ERR(sai->base);
 159
 160         of_id = of_match_device(stm32_sai_ids, &pdev->dev);
 161         if (of_id)
 162                 sai->conf = (struct stm32_sai_conf *)of_id->data;
 163         else
 164                 return -EINVAL;
 165
 166         if (!STM_SAI_IS_F4(sai)) {
 167                 sai->pclk = devm_clk_get(&pdev->dev, "pclk");
 168                 if (IS_ERR(sai->pclk)) {
 169                         dev_err(&pdev->dev, "missing bus clock pclk\n");
 170                         return PTR_ERR(sai->pclk);
 171                 }
 172         }
 173
 174         sai->clk_x8k = devm_clk_get(&pdev->dev, "x8k");
 175         if (IS_ERR(sai->clk_x8k)) {
 176                 dev_err(&pdev->dev, "missing x8k parent clock\n");
 177                 return PTR_ERR(sai->clk_x8k);
 178         }
 179
 180         sai->clk_x11k = devm_clk_get(&pdev->dev, "x11k");
 181         if (IS_ERR(sai->clk_x11k)) {
 182                 dev_err(&pdev->dev, "missing x11k parent clock\n");
 183                 return PTR_ERR(sai->clk_x11k);
 184         }
 185
 186         /* init irqs */
 187         sai->irq = platform_get_irq(pdev, 0);
 188         if (sai->irq < 0) {
 189                 dev_err(&pdev->dev, "no irq for node %s\n", pdev->name);
 190                 return sai->irq;
 191         }
 192
 193         /* reset */
 194         rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
 195         if (!IS_ERR(rst)) {
 196                 reset_control_assert(rst);
 197                 udelay(2);
 198                 reset_control_deassert(rst);
 199         }
 200
 201         sai->pdev = pdev;
 202         sai->set_sync = &stm32_sai_set_sync;
 203         platform_set_drvdata(pdev, sai);
 204
 205         return devm_of_platform_populate(&pdev->dev);
 206 }
 207
 208 #ifdef CONFIG_PM_SLEEP
 209 /*
 210  * When pins are shared by two sai sub instances, pins have to be defined
 211  * in sai parent node. In this case, pins state is not managed by alsa fw.
 212  * These pins are managed in suspend/resume callbacks.
 213  */
 214 static int stm32_sai_suspend(struct device *dev)
 215 {
 216         struct stm32_sai_data *sai = dev_get_drvdata(dev);
 217         int ret;
 218
 219         ret = stm32_sai_pclk_enable(dev);
 220         if (ret)
 221                 return ret;
 222
 223         sai->gcr = readl_relaxed(sai->base);
 224         stm32_sai_pclk_disable(dev);
 225
 226         return pinctrl_pm_select_sleep_state(dev);
 227 }
 228
 229 static int stm32_sai_resume(struct device *dev)
 230 {
 231         struct stm32_sai_data *sai = dev_get_drvdata(dev);
 232         int ret;
 233
 234         ret = stm32_sai_pclk_enable(dev);
 235         if (ret)
 236                 return ret;
 237
 238         writel_relaxed(sai->gcr, sai->base);
 239         stm32_sai_pclk_disable(dev);
 240
 241         return pinctrl_pm_select_default_state(dev);
 242 }
 243 #endif /* CONFIG_PM_SLEEP */
 244
 245 static const struct dev_pm_ops stm32_sai_pm_ops = {
 246         SET_SYSTEM_SLEEP_PM_OPS(stm32_sai_suspend, stm32_sai_resume)
 247 };
 248
 249 MODULE_DEVICE_TABLE(of, stm32_sai_ids);
 250
 251 static struct platform_driver stm32_sai_driver = {
 252         .driver = {
 253                 .name = "st,stm32-sai",
 254                 .of_match_table = stm32_sai_ids,
 255                 .pm = &stm32_sai_pm_ops,
 256         },
 257         .probe = stm32_sai_probe,
 258 };
 259
 260 module_platform_driver(stm32_sai_driver);
 261
 262 MODULE_DESCRIPTION("STM32 Soc SAI Interface");
 263 MODULE_AUTHOR("Olivier Moysan <olivier.moysan@st.com>");
 264 MODULE_ALIAS("platform:st,stm32-sai");
 265 MODULE_LICENSE("GPL v2");