1 /* 2 * Memory-mapped interface driver for DW SPI Core 3 * 4 * Copyright (c) 2010, Octasic semiconductor. 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms and conditions of the GNU General Public License, 8 * version 2, as published by the Free Software Foundation. 9 */ 10 11 #include <linux/clk.h> 12 #include <linux/err.h> 13 #include <linux/interrupt.h> 14 #include <linux/platform_device.h> 15 #include <linux/slab.h> 16 #include <linux/spi/spi.h> 17 #include <linux/scatterlist.h> 18 #include <linux/module.h> 19 #include <linux/of.h> 20 #include <linux/of_gpio.h> 21 #include <linux/of_platform.h> 22 #include <linux/property.h> 23 24 #include "spi-dw.h" 25 26 #define DRIVER_NAME "dw_spi_mmio" 27 28 struct dw_spi_mmio { 29 struct dw_spi dws; 30 struct clk *clk; 31 }; 32 33 static int dw_spi_mmio_probe(struct platform_device *pdev) 34 { 35 struct dw_spi_mmio *dwsmmio; 36 struct dw_spi *dws; 37 struct resource *mem; 38 int ret; 39 int num_cs; 40 41 dwsmmio = devm_kzalloc(&pdev->dev, sizeof(struct dw_spi_mmio), 42 GFP_KERNEL); 43 if (!dwsmmio) 44 return -ENOMEM; 45 46 dws = &dwsmmio->dws; 47 48 /* Get basic io resource and map it */ 49 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 50 if (!mem) { 51 dev_err(&pdev->dev, "no mem resource?\n"); 52 return -EINVAL; 53 } 54 55 dws->regs = devm_ioremap_resource(&pdev->dev, mem); 56 if (IS_ERR(dws->regs)) { 57 dev_err(&pdev->dev, "SPI region map failed\n"); 58 return PTR_ERR(dws->regs); 59 } 60 61 dws->irq = platform_get_irq(pdev, 0); 62 if (dws->irq < 0) { 63 dev_err(&pdev->dev, "no irq resource?\n"); 64 return dws->irq; /* -ENXIO */ 65 } 66 67 dwsmmio->clk = devm_clk_get(&pdev->dev, NULL); 68 if (IS_ERR(dwsmmio->clk)) 69 return PTR_ERR(dwsmmio->clk); 70 ret = clk_prepare_enable(dwsmmio->clk); 71 if (ret) 72 return ret; 73 74 dws->bus_num = pdev->id; 75 76 dws->max_freq = clk_get_rate(dwsmmio->clk); 77 78 device_property_read_u32(&pdev->dev, "reg-io-width", &dws->reg_io_width); 79 80 num_cs = 4; 81 82 device_property_read_u32(&pdev->dev, "num-cs", &num_cs); 83 84 dws->num_cs = num_cs; 85 86 if (pdev->dev.of_node) { 87 int i; 88 89 for (i = 0; i < dws->num_cs; i++) { 90 int cs_gpio = of_get_named_gpio(pdev->dev.of_node, 91 "cs-gpios", i); 92 93 if (cs_gpio == -EPROBE_DEFER) { 94 ret = cs_gpio; 95 goto out; 96 } 97 98 if (gpio_is_valid(cs_gpio)) { 99 ret = devm_gpio_request(&pdev->dev, cs_gpio, 100 dev_name(&pdev->dev)); 101 if (ret) 102 goto out; 103 } 104 } 105 } 106 107 ret = dw_spi_add_host(&pdev->dev, dws); 108 if (ret) 109 goto out; 110 111 platform_set_drvdata(pdev, dwsmmio); 112 return 0; 113 114 out: 115 clk_disable_unprepare(dwsmmio->clk); 116 return ret; 117 } 118 119 static int dw_spi_mmio_remove(struct platform_device *pdev) 120 { 121 struct dw_spi_mmio *dwsmmio = platform_get_drvdata(pdev); 122 123 clk_disable_unprepare(dwsmmio->clk); 124 dw_spi_remove_host(&dwsmmio->dws); 125 126 return 0; 127 } 128 129 static const struct of_device_id dw_spi_mmio_of_match[] = { 130 { .compatible = "snps,dw-apb-ssi", }, 131 { /* end of table */} 132 }; 133 MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match); 134 135 static struct platform_driver dw_spi_mmio_driver = { 136 .probe = dw_spi_mmio_probe, 137 .remove = dw_spi_mmio_remove, 138 .driver = { 139 .name = DRIVER_NAME, 140 .of_match_table = dw_spi_mmio_of_match, 141 }, 142 }; 143 module_platform_driver(dw_spi_mmio_driver); 144 145 MODULE_AUTHOR("Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>"); 146 MODULE_DESCRIPTION("Memory-mapped I/O interface driver for DW SPI Core"); 147 MODULE_LICENSE("GPL v2"); 148