1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Altera SPI driver 4 * 5 * Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw> 6 * 7 * Based on spi_s3c24xx.c, which is: 8 * Copyright (c) 2006 Ben Dooks 9 * Copyright (c) 2006 Simtec Electronics 10 * Ben Dooks <ben@simtec.co.uk> 11 */ 12 13 #include <linux/interrupt.h> 14 #include <linux/errno.h> 15 #include <linux/module.h> 16 #include <linux/platform_device.h> 17 #include <linux/spi/altera.h> 18 #include <linux/spi/spi.h> 19 #include <linux/io.h> 20 #include <linux/of.h> 21 22 #define DRV_NAME "spi_altera" 23 24 enum altera_spi_type { 25 ALTERA_SPI_TYPE_UNKNOWN, 26 ALTERA_SPI_TYPE_SUBDEV, 27 }; 28 29 static const struct regmap_config spi_altera_config = { 30 .reg_bits = 32, 31 .reg_stride = 4, 32 .val_bits = 32, 33 }; 34 35 static int altera_spi_probe(struct platform_device *pdev) 36 { 37 const struct platform_device_id *platid = platform_get_device_id(pdev); 38 struct altera_spi_platform_data *pdata = dev_get_platdata(&pdev->dev); 39 enum altera_spi_type type = ALTERA_SPI_TYPE_UNKNOWN; 40 struct altera_spi *hw; 41 struct spi_controller *host; 42 int err = -ENODEV; 43 u16 i; 44 45 host = spi_alloc_host(&pdev->dev, sizeof(struct altera_spi)); 46 if (!host) 47 return err; 48 49 /* setup the host state. */ 50 host->bus_num = -1; 51 52 if (pdata) { 53 if (pdata->num_chipselect > ALTERA_SPI_MAX_CS) { 54 dev_err(&pdev->dev, 55 "Invalid number of chipselect: %u\n", 56 pdata->num_chipselect); 57 err = -EINVAL; 58 goto exit; 59 } 60 61 host->num_chipselect = pdata->num_chipselect; 62 host->mode_bits = pdata->mode_bits; 63 host->bits_per_word_mask = pdata->bits_per_word_mask; 64 } else { 65 host->num_chipselect = 16; 66 host->mode_bits = SPI_CS_HIGH; 67 host->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 16); 68 } 69 70 hw = spi_controller_get_devdata(host); 71 hw->dev = &pdev->dev; 72 73 if (platid) 74 type = platid->driver_data; 75 76 /* find and map our resources */ 77 if (type == ALTERA_SPI_TYPE_SUBDEV) { 78 struct resource *regoff; 79 80 hw->regmap = dev_get_regmap(pdev->dev.parent, NULL); 81 if (!hw->regmap) { 82 dev_err(&pdev->dev, "get regmap failed\n"); 83 goto exit; 84 } 85 86 regoff = platform_get_resource(pdev, IORESOURCE_REG, 0); 87 if (regoff) 88 hw->regoff = regoff->start; 89 } else { 90 void __iomem *res; 91 92 res = devm_platform_ioremap_resource(pdev, 0); 93 if (IS_ERR(res)) { 94 err = PTR_ERR(res); 95 goto exit; 96 } 97 98 hw->regmap = devm_regmap_init_mmio(&pdev->dev, res, 99 &spi_altera_config); 100 if (IS_ERR(hw->regmap)) { 101 dev_err(&pdev->dev, "regmap mmio init failed\n"); 102 err = PTR_ERR(hw->regmap); 103 goto exit; 104 } 105 } 106 107 altera_spi_init_host(host); 108 109 /* irq is optional */ 110 hw->irq = platform_get_irq(pdev, 0); 111 if (hw->irq >= 0) { 112 err = devm_request_irq(&pdev->dev, hw->irq, altera_spi_irq, 0, 113 pdev->name, host); 114 if (err) 115 goto exit; 116 } 117 118 err = devm_spi_register_controller(&pdev->dev, host); 119 if (err) 120 goto exit; 121 122 if (pdata) { 123 for (i = 0; i < pdata->num_devices; i++) { 124 if (!spi_new_device(host, pdata->devices + i)) 125 dev_warn(&pdev->dev, 126 "unable to create SPI device: %s\n", 127 pdata->devices[i].modalias); 128 } 129 } 130 131 dev_info(&pdev->dev, "regoff %u, irq %d\n", hw->regoff, hw->irq); 132 133 return 0; 134 exit: 135 spi_controller_put(host); 136 return err; 137 } 138 139 #ifdef CONFIG_OF 140 static const struct of_device_id altera_spi_match[] = { 141 { .compatible = "ALTR,spi-1.0", }, 142 { .compatible = "altr,spi-1.0", }, 143 {}, 144 }; 145 MODULE_DEVICE_TABLE(of, altera_spi_match); 146 #endif /* CONFIG_OF */ 147 148 static const struct platform_device_id altera_spi_ids[] = { 149 { DRV_NAME, ALTERA_SPI_TYPE_UNKNOWN }, 150 { "subdev_spi_altera", ALTERA_SPI_TYPE_SUBDEV }, 151 { } 152 }; 153 MODULE_DEVICE_TABLE(platform, altera_spi_ids); 154 155 static struct platform_driver altera_spi_driver = { 156 .probe = altera_spi_probe, 157 .driver = { 158 .name = DRV_NAME, 159 .pm = NULL, 160 .of_match_table = of_match_ptr(altera_spi_match), 161 }, 162 .id_table = altera_spi_ids, 163 }; 164 module_platform_driver(altera_spi_driver); 165 166 MODULE_DESCRIPTION("Altera SPI driver"); 167 MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>"); 168 MODULE_LICENSE("GPL"); 169