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 host->dev.of_node = pdev->dev.of_node; 71 72 hw = spi_controller_get_devdata(host); 73 hw->dev = &pdev->dev; 74 75 if (platid) 76 type = platid->driver_data; 77 78 /* find and map our resources */ 79 if (type == ALTERA_SPI_TYPE_SUBDEV) { 80 struct resource *regoff; 81 82 hw->regmap = dev_get_regmap(pdev->dev.parent, NULL); 83 if (!hw->regmap) { 84 dev_err(&pdev->dev, "get regmap failed\n"); 85 goto exit; 86 } 87 88 regoff = platform_get_resource(pdev, IORESOURCE_REG, 0); 89 if (regoff) 90 hw->regoff = regoff->start; 91 } else { 92 void __iomem *res; 93 94 res = devm_platform_ioremap_resource(pdev, 0); 95 if (IS_ERR(res)) { 96 err = PTR_ERR(res); 97 goto exit; 98 } 99 100 hw->regmap = devm_regmap_init_mmio(&pdev->dev, res, 101 &spi_altera_config); 102 if (IS_ERR(hw->regmap)) { 103 dev_err(&pdev->dev, "regmap mmio init failed\n"); 104 err = PTR_ERR(hw->regmap); 105 goto exit; 106 } 107 } 108 109 altera_spi_init_host(host); 110 111 /* irq is optional */ 112 hw->irq = platform_get_irq(pdev, 0); 113 if (hw->irq >= 0) { 114 err = devm_request_irq(&pdev->dev, hw->irq, altera_spi_irq, 0, 115 pdev->name, host); 116 if (err) 117 goto exit; 118 } 119 120 err = devm_spi_register_controller(&pdev->dev, host); 121 if (err) 122 goto exit; 123 124 if (pdata) { 125 for (i = 0; i < pdata->num_devices; i++) { 126 if (!spi_new_device(host, pdata->devices + i)) 127 dev_warn(&pdev->dev, 128 "unable to create SPI device: %s\n", 129 pdata->devices[i].modalias); 130 } 131 } 132 133 dev_info(&pdev->dev, "regoff %u, irq %d\n", hw->regoff, hw->irq); 134 135 return 0; 136 exit: 137 spi_controller_put(host); 138 return err; 139 } 140 141 #ifdef CONFIG_OF 142 static const struct of_device_id altera_spi_match[] = { 143 { .compatible = "ALTR,spi-1.0", }, 144 { .compatible = "altr,spi-1.0", }, 145 {}, 146 }; 147 MODULE_DEVICE_TABLE(of, altera_spi_match); 148 #endif /* CONFIG_OF */ 149 150 static const struct platform_device_id altera_spi_ids[] = { 151 { DRV_NAME, ALTERA_SPI_TYPE_UNKNOWN }, 152 { "subdev_spi_altera", ALTERA_SPI_TYPE_SUBDEV }, 153 { } 154 }; 155 MODULE_DEVICE_TABLE(platform, altera_spi_ids); 156 157 static struct platform_driver altera_spi_driver = { 158 .probe = altera_spi_probe, 159 .driver = { 160 .name = DRV_NAME, 161 .pm = NULL, 162 .of_match_table = of_match_ptr(altera_spi_match), 163 }, 164 .id_table = altera_spi_ids, 165 }; 166 module_platform_driver(altera_spi_driver); 167 168 MODULE_DESCRIPTION("Altera SPI driver"); 169 MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>"); 170 MODULE_LICENSE("GPL"); 171