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 23 #include "spi-dw.h" 24 25 #define DRIVER_NAME "dw_spi_mmio" 26 27 struct dw_spi_mmio { 28 struct dw_spi dws; 29 struct clk *clk; 30 }; 31 32 static int dw_spi_mmio_probe(struct platform_device *pdev) 33 { 34 struct dw_spi_mmio *dwsmmio; 35 struct dw_spi *dws; 36 struct resource *mem; 37 int ret; 38 int num_cs; 39 40 dwsmmio = devm_kzalloc(&pdev->dev, sizeof(struct dw_spi_mmio), 41 GFP_KERNEL); 42 if (!dwsmmio) 43 return -ENOMEM; 44 45 dws = &dwsmmio->dws; 46 47 /* Get basic io resource and map it */ 48 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 49 if (!mem) { 50 dev_err(&pdev->dev, "no mem resource?\n"); 51 return -EINVAL; 52 } 53 54 dws->regs = devm_ioremap_resource(&pdev->dev, mem); 55 if (IS_ERR(dws->regs)) { 56 dev_err(&pdev->dev, "SPI region map failed\n"); 57 return PTR_ERR(dws->regs); 58 } 59 60 dws->irq = platform_get_irq(pdev, 0); 61 if (dws->irq < 0) { 62 dev_err(&pdev->dev, "no irq resource?\n"); 63 return dws->irq; /* -ENXIO */ 64 } 65 66 dwsmmio->clk = devm_clk_get(&pdev->dev, NULL); 67 if (IS_ERR(dwsmmio->clk)) 68 return PTR_ERR(dwsmmio->clk); 69 ret = clk_prepare_enable(dwsmmio->clk); 70 if (ret) 71 return ret; 72 73 dws->bus_num = pdev->id; 74 75 dws->max_freq = clk_get_rate(dwsmmio->clk); 76 77 of_property_read_u32(pdev->dev.of_node, "reg-io-width", 78 &dws->reg_io_width); 79 80 num_cs = 4; 81 82 if (pdev->dev.of_node) 83 of_property_read_u32(pdev->dev.of_node, "num-cs", &num_cs); 84 85 dws->num_cs = num_cs; 86 87 if (pdev->dev.of_node) { 88 int i; 89 90 for (i = 0; i < dws->num_cs; i++) { 91 int cs_gpio = of_get_named_gpio(pdev->dev.of_node, 92 "cs-gpios", i); 93 94 if (cs_gpio == -EPROBE_DEFER) { 95 ret = cs_gpio; 96 goto out; 97 } 98 99 if (gpio_is_valid(cs_gpio)) { 100 ret = devm_gpio_request(&pdev->dev, cs_gpio, 101 dev_name(&pdev->dev)); 102 if (ret) 103 goto out; 104 } 105 } 106 } 107 108 ret = dw_spi_add_host(&pdev->dev, dws); 109 if (ret) 110 goto out; 111 112 platform_set_drvdata(pdev, dwsmmio); 113 return 0; 114 115 out: 116 clk_disable_unprepare(dwsmmio->clk); 117 return ret; 118 } 119 120 static int dw_spi_mmio_remove(struct platform_device *pdev) 121 { 122 struct dw_spi_mmio *dwsmmio = platform_get_drvdata(pdev); 123 124 clk_disable_unprepare(dwsmmio->clk); 125 dw_spi_remove_host(&dwsmmio->dws); 126 127 return 0; 128 } 129 130 static const struct of_device_id dw_spi_mmio_of_match[] = { 131 { .compatible = "snps,dw-apb-ssi", }, 132 { /* end of table */} 133 }; 134 MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match); 135 136 static struct platform_driver dw_spi_mmio_driver = { 137 .probe = dw_spi_mmio_probe, 138 .remove = dw_spi_mmio_remove, 139 .driver = { 140 .name = DRIVER_NAME, 141 .of_match_table = dw_spi_mmio_of_match, 142 }, 143 }; 144 module_platform_driver(dw_spi_mmio_driver); 145 146 MODULE_AUTHOR("Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>"); 147 MODULE_DESCRIPTION("Memory-mapped I/O interface driver for DW SPI Core"); 148 MODULE_LICENSE("GPL v2"); 149