sound/soc/stm/stm32_sai.c

   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 stm32_sai_data *sai;
 128         struct reset_control *rst;
 129         struct resource *res;
 130         const struct of_device_id *of_id;
 131
 132         sai = devm_kzalloc(&pdev->dev, sizeof(*sai), GFP_KERNEL);
 133         if (!sai)
 134                 return -ENOMEM;
 135
 136         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 137         sai->base = devm_ioremap_resource(&pdev->dev, res);
 138         if (IS_ERR(sai->base))
 139                 return PTR_ERR(sai->base);
 140
 141         of_id = of_match_device(stm32_sai_ids, &pdev->dev);
 142         if (of_id)
 143                 sai->conf = (struct stm32_sai_conf *)of_id->data;
 144         else
 145                 return -EINVAL;
 146
 147         if (!STM_SAI_IS_F4(sai)) {
 148                 sai->pclk = devm_clk_get(&pdev->dev, "pclk");
 149                 if (IS_ERR(sai->pclk)) {
 150                         dev_err(&pdev->dev, "missing bus clock pclk\n");
 151                         return PTR_ERR(sai->pclk);
 152                 }
 153         }
 154
 155         sai->clk_x8k = devm_clk_get(&pdev->dev, "x8k");
 156         if (IS_ERR(sai->clk_x8k)) {
 157                 dev_err(&pdev->dev, "missing x8k parent clock\n");
 158                 return PTR_ERR(sai->clk_x8k);
 159         }
 160
 161         sai->clk_x11k = devm_clk_get(&pdev->dev, "x11k");
 162         if (IS_ERR(sai->clk_x11k)) {
 163                 dev_err(&pdev->dev, "missing x11k parent clock\n");
 164                 return PTR_ERR(sai->clk_x11k);
 165         }
 166
 167         /* init irqs */
 168         sai->irq = platform_get_irq(pdev, 0);
 169         if (sai->irq < 0) {
 170                 dev_err(&pdev->dev, "no irq for node %s\n", pdev->name);
 171                 return sai->irq;
 172         }
 173
 174         /* reset */
 175         rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
 176         if (!IS_ERR(rst)) {
 177                 reset_control_assert(rst);
 178                 udelay(2);
 179                 reset_control_deassert(rst);
 180         }
 181
 182         sai->pdev = pdev;
 183         sai->set_sync = &stm32_sai_set_sync;
 184         platform_set_drvdata(pdev, sai);
 185
 186         return devm_of_platform_populate(&pdev->dev);
 187 }
 188
 189 MODULE_DEVICE_TABLE(of, stm32_sai_ids);
 190
 191 static struct platform_driver stm32_sai_driver = {
 192         .driver = {
 193                 .name = "st,stm32-sai",
 194                 .of_match_table = stm32_sai_ids,
 195         },
 196         .probe = stm32_sai_probe,
 197 };
 198
 199 module_platform_driver(stm32_sai_driver);
 200
 201 MODULE_DESCRIPTION("STM32 Soc SAI Interface");
 202 MODULE_AUTHOR("Olivier Moysan <olivier.moysan@st.com>");
 203 MODULE_ALIAS("platform:st,stm32-sai");
 204 MODULE_LICENSE("GPL v2");