fdb7e884ad
The IOP3xx has some elaborate code to directly slam the GPIO lines multiplexed with I2C down low before enablement, apparently a workaround for a hardware bug found in the early chips. After consulting the developer documentation for IOP80321 and IOP80331 I can clearly see that this may be useful for IOP80321 family (mach-iop32x) but it is highly dubious for any 80331 series or later chip: in these chips the lines are not multiplexed for UARTs. We convert the code to pass optional GPIO descriptors and register these only on the 80321-based boards where it makes sense, optionally obtain them in the driver and use the gpiod_set_raw_value() to ascertain the line gets driven low when needed. The GPIO driver does not give the GPIO chip a reasonable label so the patch also adds that so that these machine descriptor tables can be used. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
64 lines
1.5 KiB
C
64 lines
1.5 KiB
C
/*
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* arch/arm/plat-iop/gpio.c
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* GPIO handling for Intel IOP3xx processors.
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*
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* Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
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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 as published by
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* the Free Software Foundation; either version 2 of the License, or (at
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* your option) any later version.
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*/
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#include <linux/err.h>
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#include <linux/module.h>
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#include <linux/gpio/driver.h>
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#include <linux/platform_device.h>
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#define IOP3XX_GPOE 0x0000
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#define IOP3XX_GPID 0x0004
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#define IOP3XX_GPOD 0x0008
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static int iop3xx_gpio_probe(struct platform_device *pdev)
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{
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struct gpio_chip *gc;
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void __iomem *base;
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int err;
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gc = devm_kzalloc(&pdev->dev, sizeof(*gc), GFP_KERNEL);
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if (!gc)
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return -ENOMEM;
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base = devm_platform_ioremap_resource(pdev, 0);
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if (IS_ERR(base))
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return PTR_ERR(base);
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err = bgpio_init(gc, &pdev->dev, 1, base + IOP3XX_GPID,
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base + IOP3XX_GPOD, NULL, NULL, base + IOP3XX_GPOE, 0);
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if (err)
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return err;
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gc->base = 0;
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gc->owner = THIS_MODULE;
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gc->label = "gpio-iop";
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return devm_gpiochip_add_data(&pdev->dev, gc, NULL);
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}
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static struct platform_driver iop3xx_gpio_driver = {
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.driver = {
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.name = "gpio-iop",
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},
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.probe = iop3xx_gpio_probe,
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};
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static int __init iop3xx_gpio_init(void)
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{
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return platform_driver_register(&iop3xx_gpio_driver);
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}
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arch_initcall(iop3xx_gpio_init);
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MODULE_DESCRIPTION("GPIO handling for Intel IOP3xx processors");
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MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
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MODULE_LICENSE("GPL");
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