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In some cases, the system bus can be configured for 16-bit mode, in this case using read/write functions for 32-bit values results in two cycles of 16 bits each, which is wrong. This patch adds the devicetree flag to switch the driver to use 16-bit mode for I/O transfers. Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Alexander Shiyan <shc_work@mail.ru> Signed-off-by: Jens Axboe <axboe@kernel.dk>
94 lines
2.3 KiB
C
94 lines
2.3 KiB
C
/*
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* OF-platform PATA driver
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*
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* Copyright (c) 2007 MontaVista Software, Inc.
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* Anton Vorontsov <avorontsov@ru.mvista.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License (Version 2) as
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* published by the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/of_address.h>
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#include <linux/platform_device.h>
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#include <linux/ata_platform.h>
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#include <linux/libata.h>
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#define DRV_NAME "pata_of_platform"
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static struct scsi_host_template pata_platform_sht = {
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ATA_PIO_SHT(DRV_NAME),
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};
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static int pata_of_platform_probe(struct platform_device *ofdev)
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{
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int ret;
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struct device_node *dn = ofdev->dev.of_node;
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struct resource io_res;
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struct resource ctl_res;
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struct resource *irq_res;
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unsigned int reg_shift = 0;
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int pio_mode = 0;
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int pio_mask;
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bool use16bit;
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ret = of_address_to_resource(dn, 0, &io_res);
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if (ret) {
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dev_err(&ofdev->dev, "can't get IO address from "
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"device tree\n");
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return -EINVAL;
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}
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ret = of_address_to_resource(dn, 1, &ctl_res);
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if (ret) {
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dev_err(&ofdev->dev, "can't get CTL address from "
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"device tree\n");
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return -EINVAL;
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}
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irq_res = platform_get_resource(ofdev, IORESOURCE_IRQ, 0);
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of_property_read_u32(dn, "reg-shift", ®_shift);
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if (!of_property_read_u32(dn, "pio-mode", &pio_mode)) {
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if (pio_mode > 6) {
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dev_err(&ofdev->dev, "invalid pio-mode\n");
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return -EINVAL;
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}
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} else {
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dev_info(&ofdev->dev, "pio-mode unspecified, assuming PIO0\n");
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}
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use16bit = of_property_read_bool(dn, "ata-generic,use16bit");
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pio_mask = 1 << pio_mode;
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pio_mask |= (1 << pio_mode) - 1;
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return __pata_platform_probe(&ofdev->dev, &io_res, &ctl_res, irq_res,
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reg_shift, pio_mask, &pata_platform_sht,
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use16bit);
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}
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static const struct of_device_id pata_of_platform_match[] = {
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{ .compatible = "ata-generic", },
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{ },
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};
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MODULE_DEVICE_TABLE(of, pata_of_platform_match);
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static struct platform_driver pata_of_platform_driver = {
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.driver = {
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.name = DRV_NAME,
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.of_match_table = pata_of_platform_match,
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},
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.probe = pata_of_platform_probe,
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.remove = ata_platform_remove_one,
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};
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module_platform_driver(pata_of_platform_driver);
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MODULE_DESCRIPTION("OF-platform PATA driver");
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MODULE_AUTHOR("Anton Vorontsov <avorontsov@ru.mvista.com>");
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MODULE_LICENSE("GPL");
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