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_gpio.h> 20 21 #include "spi-dw.h" 22 23 #define DRIVER_NAME "dw_spi_mmio" 24 25 struct dw_spi_mmio { 26 struct dw_spi dws; 27 struct clk *clk; 28 }; 29 30 static int dw_spi_mmio_probe(struct platform_device *pdev) 31 { 32 struct dw_spi_mmio *dwsmmio; 33 struct dw_spi *dws; 34 struct resource *mem; 35 int ret; 36 37 dwsmmio = devm_kzalloc(&pdev->dev, sizeof(struct dw_spi_mmio), 38 GFP_KERNEL); 39 if (!dwsmmio) 40 return -ENOMEM; 41 42 dws = &dwsmmio->dws; 43 44 /* Get basic io resource and map it */ 45 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 46 if (!mem) { 47 dev_err(&pdev->dev, "no mem resource?\n"); 48 return -EINVAL; 49 } 50 51 dws->regs = devm_ioremap_resource(&pdev->dev, mem); 52 if (IS_ERR(dws->regs)) { 53 dev_err(&pdev->dev, "SPI region map failed\n"); 54 return PTR_ERR(dws->regs); 55 } 56 57 dws->irq = platform_get_irq(pdev, 0); 58 if (dws->irq < 0) { 59 dev_err(&pdev->dev, "no irq resource?\n"); 60 return dws->irq; /* -ENXIO */ 61 } 62 63 dwsmmio->clk = devm_clk_get(&pdev->dev, NULL); 64 if (IS_ERR(dwsmmio->clk)) 65 return PTR_ERR(dwsmmio->clk); 66 ret = clk_prepare_enable(dwsmmio->clk); 67 if (ret) 68 return ret; 69 70 dws->bus_num = pdev->id; 71 dws->num_cs = 4; 72 dws->max_freq = clk_get_rate(dwsmmio->clk); 73 74 if (pdev->dev.of_node) { 75 int i; 76 77 for (i = 0; i < dws->num_cs; i++) { 78 int cs_gpio = of_get_named_gpio(pdev->dev.of_node, 79 "cs-gpios", i); 80 81 if (cs_gpio == -EPROBE_DEFER) { 82 ret = cs_gpio; 83 goto out; 84 } 85 86 if (gpio_is_valid(cs_gpio)) { 87 ret = devm_gpio_request(&pdev->dev, cs_gpio, 88 dev_name(&pdev->dev)); 89 if (ret) 90 goto out; 91 } 92 } 93 } 94 95 ret = dw_spi_add_host(&pdev->dev, dws); 96 if (ret) 97 goto out; 98 99 platform_set_drvdata(pdev, dwsmmio); 100 return 0; 101 102 out: 103 clk_disable_unprepare(dwsmmio->clk); 104 return ret; 105 } 106 107 static int dw_spi_mmio_remove(struct platform_device *pdev) 108 { 109 struct dw_spi_mmio *dwsmmio = platform_get_drvdata(pdev); 110 111 clk_disable_unprepare(dwsmmio->clk); 112 dw_spi_remove_host(&dwsmmio->dws); 113 114 return 0; 115 } 116 117 static struct platform_driver dw_spi_mmio_driver = { 118 .probe = dw_spi_mmio_probe, 119 .remove = dw_spi_mmio_remove, 120 .driver = { 121 .name = DRIVER_NAME, 122 .owner = THIS_MODULE, 123 }, 124 }; 125 module_platform_driver(dw_spi_mmio_driver); 126 127 MODULE_AUTHOR("Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>"); 128 MODULE_DESCRIPTION("Memory-mapped I/O interface driver for DW SPI Core"); 129 MODULE_LICENSE("GPL v2"); 130