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 dws->regs = devm_ioremap_resource(&pdev->dev, mem); 51 if (IS_ERR(dws->regs)) { 52 dev_err(&pdev->dev, "SPI region map failed\n"); 53 return PTR_ERR(dws->regs); 54 } 55 56 dws->irq = platform_get_irq(pdev, 0); 57 if (dws->irq < 0) { 58 dev_err(&pdev->dev, "no irq resource?\n"); 59 return dws->irq; /* -ENXIO */ 60 } 61 62 dwsmmio->clk = devm_clk_get(&pdev->dev, NULL); 63 if (IS_ERR(dwsmmio->clk)) 64 return PTR_ERR(dwsmmio->clk); 65 ret = clk_prepare_enable(dwsmmio->clk); 66 if (ret) 67 return ret; 68 69 dws->bus_num = pdev->id; 70 71 dws->max_freq = clk_get_rate(dwsmmio->clk); 72 73 device_property_read_u32(&pdev->dev, "reg-io-width", &dws->reg_io_width); 74 75 num_cs = 4; 76 77 device_property_read_u32(&pdev->dev, "num-cs", &num_cs); 78 79 dws->num_cs = num_cs; 80 81 if (pdev->dev.of_node) { 82 int i; 83 84 for (i = 0; i < dws->num_cs; i++) { 85 int cs_gpio = of_get_named_gpio(pdev->dev.of_node, 86 "cs-gpios", i); 87 88 if (cs_gpio == -EPROBE_DEFER) { 89 ret = cs_gpio; 90 goto out; 91 } 92 93 if (gpio_is_valid(cs_gpio)) { 94 ret = devm_gpio_request(&pdev->dev, cs_gpio, 95 dev_name(&pdev->dev)); 96 if (ret) 97 goto out; 98 } 99 } 100 } 101 102 ret = dw_spi_add_host(&pdev->dev, dws); 103 if (ret) 104 goto out; 105 106 platform_set_drvdata(pdev, dwsmmio); 107 return 0; 108 109 out: 110 clk_disable_unprepare(dwsmmio->clk); 111 return ret; 112 } 113 114 static int dw_spi_mmio_remove(struct platform_device *pdev) 115 { 116 struct dw_spi_mmio *dwsmmio = platform_get_drvdata(pdev); 117 118 dw_spi_remove_host(&dwsmmio->dws); 119 clk_disable_unprepare(dwsmmio->clk); 120 121 return 0; 122 } 123 124 static const struct of_device_id dw_spi_mmio_of_match[] = { 125 { .compatible = "snps,dw-apb-ssi", }, 126 { /* end of table */} 127 }; 128 MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match); 129 130 static struct platform_driver dw_spi_mmio_driver = { 131 .probe = dw_spi_mmio_probe, 132 .remove = dw_spi_mmio_remove, 133 .driver = { 134 .name = DRIVER_NAME, 135 .of_match_table = dw_spi_mmio_of_match, 136 }, 137 }; 138 module_platform_driver(dw_spi_mmio_driver); 139 140 MODULE_AUTHOR("Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>"); 141 MODULE_DESCRIPTION("Memory-mapped I/O interface driver for DW SPI Core"); 142 MODULE_LICENSE("GPL v2"); 143