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 num_cs = 4; 78 79 if (pdev->dev.of_node) 80 of_property_read_u32(pdev->dev.of_node, "num-cs", &num_cs); 81 82 dws->num_cs = num_cs; 83 84 if (pdev->dev.of_node) { 85 int i; 86 87 for (i = 0; i < dws->num_cs; i++) { 88 int cs_gpio = of_get_named_gpio(pdev->dev.of_node, 89 "cs-gpios", i); 90 91 if (cs_gpio == -EPROBE_DEFER) { 92 ret = cs_gpio; 93 goto out; 94 } 95 96 if (gpio_is_valid(cs_gpio)) { 97 ret = devm_gpio_request(&pdev->dev, cs_gpio, 98 dev_name(&pdev->dev)); 99 if (ret) 100 goto out; 101 } 102 } 103 } 104 105 ret = dw_spi_add_host(&pdev->dev, dws); 106 if (ret) 107 goto out; 108 109 platform_set_drvdata(pdev, dwsmmio); 110 return 0; 111 112 out: 113 clk_disable_unprepare(dwsmmio->clk); 114 return ret; 115 } 116 117 static int dw_spi_mmio_remove(struct platform_device *pdev) 118 { 119 struct dw_spi_mmio *dwsmmio = platform_get_drvdata(pdev); 120 121 clk_disable_unprepare(dwsmmio->clk); 122 dw_spi_remove_host(&dwsmmio->dws); 123 124 return 0; 125 } 126 127 static const struct of_device_id dw_spi_mmio_of_match[] = { 128 { .compatible = "snps,dw-apb-ssi", }, 129 { /* end of table */} 130 }; 131 MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match); 132 133 static struct platform_driver dw_spi_mmio_driver = { 134 .probe = dw_spi_mmio_probe, 135 .remove = dw_spi_mmio_remove, 136 .driver = { 137 .name = DRIVER_NAME, 138 .of_match_table = dw_spi_mmio_of_match, 139 }, 140 }; 141 module_platform_driver(dw_spi_mmio_driver); 142 143 MODULE_AUTHOR("Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>"); 144 MODULE_DESCRIPTION("Memory-mapped I/O interface driver for DW SPI Core"); 145 MODULE_LICENSE("GPL v2"); 146