![Jamie Iles](/assets/img/avatar_default.png)
clk_get() returns a struct clk cookie to the driver and some platforms may return NULL if they only support a single clock. clk_get() has only failed if it returns a ERR_PTR() encoded pointer. Signed-off-by: Jamie Iles <jamie@jamieiles.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
150 lines
3.3 KiB
C
150 lines
3.3 KiB
C
/*
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* dw_spi_mmio.c - Memory-mapped interface driver for DW SPI Core
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*
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* Copyright (c) 2010, Octasic semiconductor.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*/
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#include <linux/clk.h>
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#include <linux/err.h>
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#include <linux/interrupt.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <linux/spi/dw_spi.h>
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#include <linux/spi/spi.h>
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#define DRIVER_NAME "dw_spi_mmio"
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struct dw_spi_mmio {
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struct dw_spi dws;
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struct clk *clk;
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};
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static int __devinit dw_spi_mmio_probe(struct platform_device *pdev)
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{
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struct dw_spi_mmio *dwsmmio;
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struct dw_spi *dws;
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struct resource *mem, *ioarea;
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int ret;
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dwsmmio = kzalloc(sizeof(struct dw_spi_mmio), GFP_KERNEL);
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if (!dwsmmio) {
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ret = -ENOMEM;
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goto err_end;
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}
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dws = &dwsmmio->dws;
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/* Get basic io resource and map it */
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mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!mem) {
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dev_err(&pdev->dev, "no mem resource?\n");
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ret = -EINVAL;
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goto err_kfree;
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}
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ioarea = request_mem_region(mem->start, resource_size(mem),
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pdev->name);
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if (!ioarea) {
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dev_err(&pdev->dev, "SPI region already claimed\n");
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ret = -EBUSY;
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goto err_kfree;
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}
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dws->regs = ioremap_nocache(mem->start, resource_size(mem));
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if (!dws->regs) {
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dev_err(&pdev->dev, "SPI region already mapped\n");
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ret = -ENOMEM;
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goto err_release_reg;
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}
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dws->irq = platform_get_irq(pdev, 0);
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if (dws->irq < 0) {
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dev_err(&pdev->dev, "no irq resource?\n");
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ret = dws->irq; /* -ENXIO */
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goto err_unmap;
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}
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dwsmmio->clk = clk_get(&pdev->dev, NULL);
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if (IS_ERR(dwsmmio->clk)) {
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ret = PTR_ERR(dwsmmio->clk);
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goto err_irq;
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}
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clk_enable(dwsmmio->clk);
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dws->parent_dev = &pdev->dev;
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dws->bus_num = 0;
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dws->num_cs = 4;
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dws->max_freq = clk_get_rate(dwsmmio->clk);
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ret = dw_spi_add_host(dws);
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if (ret)
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goto err_clk;
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platform_set_drvdata(pdev, dwsmmio);
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return 0;
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err_clk:
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clk_disable(dwsmmio->clk);
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clk_put(dwsmmio->clk);
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dwsmmio->clk = NULL;
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err_irq:
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free_irq(dws->irq, dws);
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err_unmap:
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iounmap(dws->regs);
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err_release_reg:
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release_mem_region(mem->start, resource_size(mem));
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err_kfree:
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kfree(dwsmmio);
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err_end:
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return ret;
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}
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static int __devexit dw_spi_mmio_remove(struct platform_device *pdev)
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{
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struct dw_spi_mmio *dwsmmio = platform_get_drvdata(pdev);
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struct resource *mem;
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platform_set_drvdata(pdev, NULL);
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clk_disable(dwsmmio->clk);
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clk_put(dwsmmio->clk);
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dwsmmio->clk = NULL;
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free_irq(dwsmmio->dws.irq, &dwsmmio->dws);
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dw_spi_remove_host(&dwsmmio->dws);
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iounmap(dwsmmio->dws.regs);
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kfree(dwsmmio);
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mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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release_mem_region(mem->start, resource_size(mem));
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return 0;
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}
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static struct platform_driver dw_spi_mmio_driver = {
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.remove = __devexit_p(dw_spi_mmio_remove),
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.driver = {
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.name = DRIVER_NAME,
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.owner = THIS_MODULE,
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},
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};
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static int __init dw_spi_mmio_init(void)
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{
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return platform_driver_probe(&dw_spi_mmio_driver, dw_spi_mmio_probe);
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}
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module_init(dw_spi_mmio_init);
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static void __exit dw_spi_mmio_exit(void)
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{
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platform_driver_unregister(&dw_spi_mmio_driver);
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}
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module_exit(dw_spi_mmio_exit);
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MODULE_AUTHOR("Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>");
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MODULE_DESCRIPTION("Memory-mapped I/O interface driver for DW SPI Core");
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MODULE_LICENSE("GPL v2");
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