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 .fast_io = true, 34 }; 35 36 static int altera_spi_probe(struct platform_device *pdev) 37 { 38 const struct platform_device_id *platid = platform_get_device_id(pdev); 39 struct altera_spi_platform_data *pdata = dev_get_platdata(&pdev->dev); 40 enum altera_spi_type type = ALTERA_SPI_TYPE_UNKNOWN; 41 struct altera_spi *hw; 42 struct spi_master *master; 43 int err = -ENODEV; 44 u16 i; 45 46 master = spi_alloc_master(&pdev->dev, sizeof(struct altera_spi)); 47 if (!master) 48 return err; 49 50 /* setup the master state. */ 51 master->bus_num = pdev->id; 52 53 if (pdata) { 54 if (pdata->num_chipselect > ALTERA_SPI_MAX_CS) { 55 dev_err(&pdev->dev, 56 "Invalid number of chipselect: %u\n", 57 pdata->num_chipselect); 58 err = -EINVAL; 59 goto exit; 60 } 61 62 master->num_chipselect = pdata->num_chipselect; 63 master->mode_bits = pdata->mode_bits; 64 master->bits_per_word_mask = pdata->bits_per_word_mask; 65 } else { 66 master->num_chipselect = 16; 67 master->mode_bits = SPI_CS_HIGH; 68 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 16); 69 } 70 71 master->dev.of_node = pdev->dev.of_node; 72 73 hw = spi_master_get_devdata(master); 74 hw->dev = &pdev->dev; 75 76 if (platid) 77 type = platid->driver_data; 78 79 /* find and map our resources */ 80 if (type == ALTERA_SPI_TYPE_SUBDEV) { 81 struct resource *regoff; 82 83 hw->regmap = dev_get_regmap(pdev->dev.parent, NULL); 84 if (!hw->regmap) { 85 dev_err(&pdev->dev, "get regmap failed\n"); 86 goto exit; 87 } 88 89 regoff = platform_get_resource(pdev, IORESOURCE_REG, 0); 90 if (regoff) 91 hw->regoff = regoff->start; 92 } else { 93 void __iomem *res; 94 95 res = devm_platform_ioremap_resource(pdev, 0); 96 if (IS_ERR(res)) { 97 err = PTR_ERR(res); 98 goto exit; 99 } 100 101 hw->regmap = devm_regmap_init_mmio(&pdev->dev, res, 102 &spi_altera_config); 103 if (IS_ERR(hw->regmap)) { 104 dev_err(&pdev->dev, "regmap mmio init failed\n"); 105 err = PTR_ERR(hw->regmap); 106 goto exit; 107 } 108 } 109 110 altera_spi_init_master(master); 111 112 /* irq is optional */ 113 hw->irq = platform_get_irq(pdev, 0); 114 if (hw->irq >= 0) { 115 err = devm_request_irq(&pdev->dev, hw->irq, altera_spi_irq, 0, 116 pdev->name, master); 117 if (err) 118 goto exit; 119 } 120 121 err = devm_spi_register_master(&pdev->dev, master); 122 if (err) 123 goto exit; 124 125 if (pdata) { 126 for (i = 0; i < pdata->num_devices; i++) { 127 if (!spi_new_device(master, pdata->devices + i)) 128 dev_warn(&pdev->dev, 129 "unable to create SPI device: %s\n", 130 pdata->devices[i].modalias); 131 } 132 } 133 134 dev_info(&pdev->dev, "regoff %u, irq %d\n", hw->regoff, hw->irq); 135 136 return 0; 137 exit: 138 spi_master_put(master); 139 return err; 140 } 141 142 #ifdef CONFIG_OF 143 static const struct of_device_id altera_spi_match[] = { 144 { .compatible = "ALTR,spi-1.0", }, 145 { .compatible = "altr,spi-1.0", }, 146 {}, 147 }; 148 MODULE_DEVICE_TABLE(of, altera_spi_match); 149 #endif /* CONFIG_OF */ 150 151 static const struct platform_device_id altera_spi_ids[] = { 152 { DRV_NAME, ALTERA_SPI_TYPE_UNKNOWN }, 153 { "subdev_spi_altera", ALTERA_SPI_TYPE_SUBDEV }, 154 { } 155 }; 156 MODULE_DEVICE_TABLE(platform, altera_spi_ids); 157 158 static struct platform_driver altera_spi_driver = { 159 .probe = altera_spi_probe, 160 .driver = { 161 .name = DRV_NAME, 162 .pm = NULL, 163 .of_match_table = of_match_ptr(altera_spi_match), 164 }, 165 .id_table = altera_spi_ids, 166 }; 167 module_platform_driver(altera_spi_driver); 168 169 MODULE_DESCRIPTION("Altera SPI driver"); 170 MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>"); 171 MODULE_LICENSE("GPL"); 172 MODULE_ALIAS("platform:" DRV_NAME); 173