cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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pxa930_rotary.c (4376B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Driver for the enhanced rotary controller on pxa930 and pxa935
      4 */
      5
      6#include <linux/kernel.h>
      7#include <linux/module.h>
      8#include <linux/interrupt.h>
      9#include <linux/input.h>
     10#include <linux/platform_device.h>
     11#include <linux/io.h>
     12#include <linux/slab.h>
     13
     14#include <linux/platform_data/keyboard-pxa930_rotary.h>
     15
     16#define SBCR	(0x04)
     17#define ERCR	(0x0c)
     18
     19#define SBCR_ERSB	(1 << 5)
     20
     21struct pxa930_rotary {
     22	struct input_dev	*input_dev;
     23	void __iomem		*mmio_base;
     24	int			last_ercr;
     25
     26	struct pxa930_rotary_platform_data *pdata;
     27};
     28
     29static void clear_sbcr(struct pxa930_rotary *r)
     30{
     31	uint32_t sbcr = __raw_readl(r->mmio_base + SBCR);
     32
     33	__raw_writel(sbcr | SBCR_ERSB, r->mmio_base + SBCR);
     34	__raw_writel(sbcr & ~SBCR_ERSB, r->mmio_base + SBCR);
     35}
     36
     37static irqreturn_t rotary_irq(int irq, void *dev_id)
     38{
     39	struct pxa930_rotary *r = dev_id;
     40	struct pxa930_rotary_platform_data *pdata = r->pdata;
     41	int ercr, delta, key;
     42
     43	ercr = __raw_readl(r->mmio_base + ERCR) & 0xf;
     44	clear_sbcr(r);
     45
     46	delta = ercr - r->last_ercr;
     47	if (delta == 0)
     48		return IRQ_HANDLED;
     49
     50	r->last_ercr = ercr;
     51
     52	if (pdata->up_key && pdata->down_key) {
     53		key = (delta > 0) ? pdata->up_key : pdata->down_key;
     54		input_report_key(r->input_dev, key, 1);
     55		input_sync(r->input_dev);
     56		input_report_key(r->input_dev, key, 0);
     57	} else
     58		input_report_rel(r->input_dev, pdata->rel_code, delta);
     59
     60	input_sync(r->input_dev);
     61
     62	return IRQ_HANDLED;
     63}
     64
     65static int pxa930_rotary_open(struct input_dev *dev)
     66{
     67	struct pxa930_rotary *r = input_get_drvdata(dev);
     68
     69	clear_sbcr(r);
     70
     71	return 0;
     72}
     73
     74static void pxa930_rotary_close(struct input_dev *dev)
     75{
     76	struct pxa930_rotary *r = input_get_drvdata(dev);
     77
     78	clear_sbcr(r);
     79}
     80
     81static int pxa930_rotary_probe(struct platform_device *pdev)
     82{
     83	struct pxa930_rotary_platform_data *pdata =
     84			dev_get_platdata(&pdev->dev);
     85	struct pxa930_rotary *r;
     86	struct input_dev *input_dev;
     87	struct resource *res;
     88	int irq;
     89	int err;
     90
     91	irq = platform_get_irq(pdev, 0);
     92	if (irq < 0)
     93		return -ENXIO;
     94
     95	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
     96	if (!res) {
     97		dev_err(&pdev->dev, "no I/O memory defined\n");
     98		return -ENXIO;
     99	}
    100
    101	if (!pdata) {
    102		dev_err(&pdev->dev, "no platform data defined\n");
    103		return -EINVAL;
    104	}
    105
    106	r = kzalloc(sizeof(struct pxa930_rotary), GFP_KERNEL);
    107	if (!r)
    108		return -ENOMEM;
    109
    110	r->mmio_base = ioremap(res->start, resource_size(res));
    111	if (r->mmio_base == NULL) {
    112		dev_err(&pdev->dev, "failed to remap IO memory\n");
    113		err = -ENXIO;
    114		goto failed_free;
    115	}
    116
    117	r->pdata = pdata;
    118	platform_set_drvdata(pdev, r);
    119
    120	/* allocate and register the input device */
    121	input_dev = input_allocate_device();
    122	if (!input_dev) {
    123		dev_err(&pdev->dev, "failed to allocate input device\n");
    124		err = -ENOMEM;
    125		goto failed_free_io;
    126	}
    127
    128	input_dev->name = pdev->name;
    129	input_dev->id.bustype = BUS_HOST;
    130	input_dev->open = pxa930_rotary_open;
    131	input_dev->close = pxa930_rotary_close;
    132	input_dev->dev.parent = &pdev->dev;
    133
    134	if (pdata->up_key && pdata->down_key) {
    135		__set_bit(pdata->up_key, input_dev->keybit);
    136		__set_bit(pdata->down_key, input_dev->keybit);
    137		__set_bit(EV_KEY, input_dev->evbit);
    138	} else {
    139		__set_bit(pdata->rel_code, input_dev->relbit);
    140		__set_bit(EV_REL, input_dev->evbit);
    141	}
    142
    143	r->input_dev = input_dev;
    144	input_set_drvdata(input_dev, r);
    145
    146	err = request_irq(irq, rotary_irq, 0,
    147			"enhanced rotary", r);
    148	if (err) {
    149		dev_err(&pdev->dev, "failed to request IRQ\n");
    150		goto failed_free_input;
    151	}
    152
    153	err = input_register_device(input_dev);
    154	if (err) {
    155		dev_err(&pdev->dev, "failed to register input device\n");
    156		goto failed_free_irq;
    157	}
    158
    159	return 0;
    160
    161failed_free_irq:
    162	free_irq(irq, r);
    163failed_free_input:
    164	input_free_device(input_dev);
    165failed_free_io:
    166	iounmap(r->mmio_base);
    167failed_free:
    168	kfree(r);
    169	return err;
    170}
    171
    172static int pxa930_rotary_remove(struct platform_device *pdev)
    173{
    174	struct pxa930_rotary *r = platform_get_drvdata(pdev);
    175
    176	free_irq(platform_get_irq(pdev, 0), r);
    177	input_unregister_device(r->input_dev);
    178	iounmap(r->mmio_base);
    179	kfree(r);
    180
    181	return 0;
    182}
    183
    184static struct platform_driver pxa930_rotary_driver = {
    185	.driver		= {
    186		.name	= "pxa930-rotary",
    187	},
    188	.probe		= pxa930_rotary_probe,
    189	.remove		= pxa930_rotary_remove,
    190};
    191module_platform_driver(pxa930_rotary_driver);
    192
    193MODULE_LICENSE("GPL");
    194MODULE_DESCRIPTION("Driver for PXA93x Enhanced Rotary Controller");
    195MODULE_AUTHOR("Yao Yong <yaoyong@marvell.com>");