cregit-Linux how code gets into the kernel

Release 4.7 drivers/input/mouse/navpoint.c

/*
 * Synaptics NavPoint (PXA27x SSP/SPI) driver.
 *
 * Copyright (C) 2012 Paul Parsons <lost.distance@yahoo.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/gpio.h>
#include <linux/input.h>
#include <linux/input/navpoint.h>
#include <linux/interrupt.h>
#include <linux/mutex.h>
#include <linux/pxa2xx_ssp.h>
#include <linux/slab.h>

/*
 * Synaptics Modular Embedded Protocol: Module Packet Format.
 * Module header byte 2:0 = Length (# bytes that follow)
 * Module header byte 4:3 = Control
 * Module header byte 7:5 = Module Address
 */

#define HEADER_LENGTH(byte)	((byte) & 0x07)

#define HEADER_CONTROL(byte)	(((byte) >> 3) & 0x03)

#define HEADER_ADDRESS(byte)	((byte) >> 5)


struct navpoint {
	
struct ssp_device	*ssp;
	
struct input_dev	*input;
	
struct device		*dev;
	
int			gpio;
	
int			index;
	
u8			data[1 + HEADER_LENGTH(0xff)];
};

/*
 * Initialization values for SSCR0_x, SSCR1_x, SSSR_x.
 */

static const u32 sscr0 = 0
	| SSCR0_TUM		/* TIM = 1; No TUR interrupts */
	| SSCR0_RIM		/* RIM = 1; No ROR interrupts */
	| SSCR0_SSE		/* SSE = 1; SSP enabled */
	| SSCR0_Motorola	/* FRF = 0; Motorola SPI */
	| SSCR0_DataSize(16)	/* DSS = 15; Data size = 16-bit */
	;

static const u32 sscr1 = 0
	| SSCR1_SCFR		/* SCFR = 1; SSPSCLK only during transfers */
	| SSCR1_SCLKDIR		/* SCLKDIR = 1; Slave mode */
	| SSCR1_SFRMDIR		/* SFRMDIR = 1; Slave mode */
	| SSCR1_RWOT		/* RWOT = 1; Receive without transmit mode */
	| SSCR1_RxTresh(1)	/* RFT = 0; Receive FIFO threshold = 1 */
	| SSCR1_SPH		/* SPH = 1; SSPSCLK inactive 0.5 + 1 cycles */
	| SSCR1_RIE		/* RIE = 1; Receive FIFO interrupt enabled */
	;

static const u32 sssr = 0
	| SSSR_BCE		/* BCE = 1; Clear BCE */
	| SSSR_TUR		/* TUR = 1; Clear TUR */
	| SSSR_EOC		/* EOC = 1; Clear EOC */
	| SSSR_TINT		/* TINT = 1; Clear TINT */
	| SSSR_PINT		/* PINT = 1; Clear PINT */
	| SSSR_ROR		/* ROR = 1; Clear ROR */
	;

/*
 * MEP Query $22: Touchpad Coordinate Range Query is not supported by
 * the NavPoint module, so sampled values provide the default limits.
 */

#define NAVPOINT_X_MIN		1278

#define NAVPOINT_X_MAX		5340

#define NAVPOINT_Y_MIN		1572

#define NAVPOINT_Y_MAX		4396

#define NAVPOINT_PRESSURE_MIN	0

#define NAVPOINT_PRESSURE_MAX	255


static void navpoint_packet(struct navpoint *navpoint) { int finger; int gesture; int x, y, z; switch (navpoint->data[0]) { case 0xff: /* Garbage (packet?) between reset and Hello packet */ case 0x00: /* Module 0, NULL packet */ break; case 0x0e: /* Module 0, Absolute packet */ finger = (navpoint->data[1] & 0x01); gesture = (navpoint->data[1] & 0x02); x = ((navpoint->data[2] & 0x1f) << 8) | navpoint->data[3]; y = ((navpoint->data[4] & 0x1f) << 8) | navpoint->data[5]; z = navpoint->data[6]; input_report_key(navpoint->input, BTN_TOUCH, finger); input_report_abs(navpoint->input, ABS_X, x); input_report_abs(navpoint->input, ABS_Y, y); input_report_abs(navpoint->input, ABS_PRESSURE, z); input_report_key(navpoint->input, BTN_TOOL_FINGER, finger); input_report_key(navpoint->input, BTN_LEFT, gesture); input_sync(navpoint->input); break; case 0x19: /* Module 0, Hello packet */ if ((navpoint->data[1] & 0xf0) == 0x10) break; /* FALLTHROUGH */ default: dev_warn(navpoint->dev, "spurious packet: data=0x%02x,0x%02x,...\n", navpoint->data[0], navpoint->data[1]); break; } }

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paul parsonspaul parsons251100.00%1100.00%
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static irqreturn_t navpoint_irq(int irq, void *dev_id) { struct navpoint *navpoint = dev_id; struct ssp_device *ssp = navpoint->ssp; irqreturn_t ret = IRQ_NONE; u32 status; status = pxa_ssp_read_reg(ssp, SSSR); if (status & sssr) { dev_warn(navpoint->dev, "unexpected interrupt: status=0x%08x\n", status); pxa_ssp_write_reg(ssp, SSSR, (status & sssr)); ret = IRQ_HANDLED; } while (status & SSSR_RNE) { u32 data; data = pxa_ssp_read_reg(ssp, SSDR); navpoint->data[navpoint->index + 0] = (data >> 8); navpoint->data[navpoint->index + 1] = data; navpoint->index += 2; if (HEADER_LENGTH(navpoint->data[0]) < navpoint->index) { navpoint_packet(navpoint); navpoint->index = 0; } status = pxa_ssp_read_reg(ssp, SSSR); ret = IRQ_HANDLED; } return ret; }

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paul parsonspaul parsons183100.00%1100.00%
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static void navpoint_up(struct navpoint *navpoint) { struct ssp_device *ssp = navpoint->ssp; int timeout; clk_prepare_enable(ssp->clk); pxa_ssp_write_reg(ssp, SSCR1, sscr1); pxa_ssp_write_reg(ssp, SSSR, sssr); pxa_ssp_write_reg(ssp, SSTO, 0); pxa_ssp_write_reg(ssp, SSCR0, sscr0); /* SSCR0_SSE written last */ /* Wait until SSP port is ready for slave clock operations */ for (timeout = 100; timeout != 0; --timeout) { if (!(pxa_ssp_read_reg(ssp, SSSR) & SSSR_CSS)) break; msleep(1); } if (timeout == 0) dev_err(navpoint->dev, "timeout waiting for SSSR[CSS] to clear\n"); if (gpio_is_valid(navpoint->gpio)) gpio_set_value(navpoint->gpio, 1); }

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paul parsonspaul parsons136100.00%1100.00%
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static void navpoint_down(struct navpoint *navpoint) { struct ssp_device *ssp = navpoint->ssp; if (gpio_is_valid(navpoint->gpio)) gpio_set_value(navpoint->gpio, 0); pxa_ssp_write_reg(ssp, SSCR0, 0); clk_disable_unprepare(ssp->clk); }

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paul parsonspaul parsons54100.00%1100.00%
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static int navpoint_open(struct input_dev *input) { struct navpoint *navpoint = input_get_drvdata(input); navpoint_up(navpoint); return 0; }

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paul parsonspaul parsons29100.00%1100.00%
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static void navpoint_close(struct input_dev *input) { struct navpoint *navpoint = input_get_drvdata(input); navpoint_down(navpoint); }

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paul parsonspaul parsons26100.00%1100.00%
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static int navpoint_probe(struct platform_device *pdev) { const struct navpoint_platform_data *pdata = dev_get_platdata(&pdev->dev); struct ssp_device *ssp; struct input_dev *input; struct navpoint *navpoint; int error; if (!pdata) { dev_err(&pdev->dev, "no platform data\n"); return -EINVAL; } if (gpio_is_valid(pdata->gpio)) { error = gpio_request_one(pdata->gpio, GPIOF_OUT_INIT_LOW, "SYNAPTICS_ON"); if (error) return error; } ssp = pxa_ssp_request(pdata->port, pdev->name); if (!ssp) { error = -ENODEV; goto err_free_gpio; } /* HaRET does not disable devices before jumping into Linux */ if (pxa_ssp_read_reg(ssp, SSCR0) & SSCR0_SSE) { pxa_ssp_write_reg(ssp, SSCR0, 0); dev_warn(&pdev->dev, "ssp%d already enabled\n", pdata->port); } navpoint = kzalloc(sizeof(*navpoint), GFP_KERNEL); input = input_allocate_device(); if (!navpoint || !input) { error = -ENOMEM; goto err_free_mem; } navpoint->ssp = ssp; navpoint->input = input; navpoint->dev = &pdev->dev; navpoint->gpio = pdata->gpio; input->name = pdev->name; input->dev.parent = &pdev->dev; __set_bit(EV_KEY, input->evbit); __set_bit(EV_ABS, input->evbit); __set_bit(BTN_LEFT, input->keybit); __set_bit(BTN_TOUCH, input->keybit); __set_bit(BTN_TOOL_FINGER, input->keybit); input_set_abs_params(input, ABS_X, NAVPOINT_X_MIN, NAVPOINT_X_MAX, 0, 0); input_set_abs_params(input, ABS_Y, NAVPOINT_Y_MIN, NAVPOINT_Y_MAX, 0, 0); input_set_abs_params(input, ABS_PRESSURE, NAVPOINT_PRESSURE_MIN, NAVPOINT_PRESSURE_MAX, 0, 0); input->open = navpoint_open; input->close = navpoint_close; input_set_drvdata(input, navpoint); error = request_irq(ssp->irq, navpoint_irq, 0, pdev->name, navpoint); if (error) goto err_free_mem; error = input_register_device(input); if (error) goto err_free_irq; platform_set_drvdata(pdev, navpoint); dev_dbg(&pdev->dev, "ssp%d, irq %d\n", pdata->port, ssp->irq); return 0; err_free_irq: free_irq(ssp->irq, navpoint); err_free_mem: input_free_device(input); kfree(navpoint); pxa_ssp_free(ssp); err_free_gpio: if (gpio_is_valid(pdata->gpio)) gpio_free(pdata->gpio); return error; }

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paul parsonspaul parsons46999.79%150.00%
lars-peter clausenlars-peter clausen10.21%150.00%
Total470100.00%2100.00%


static int navpoint_remove(struct platform_device *pdev) { const struct navpoint_platform_data *pdata = dev_get_platdata(&pdev->dev); struct navpoint *navpoint = platform_get_drvdata(pdev); struct ssp_device *ssp = navpoint->ssp; free_irq(ssp->irq, navpoint); input_unregister_device(navpoint->input); kfree(navpoint); pxa_ssp_free(ssp); if (gpio_is_valid(pdata->gpio)) gpio_free(pdata->gpio); return 0; }

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paul parsonspaul parsons89100.00%1100.00%
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static int __maybe_unused navpoint_suspend(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct navpoint *navpoint = platform_get_drvdata(pdev); struct input_dev *input = navpoint->input; mutex_lock(&input->mutex); if (input->users) navpoint_down(navpoint); mutex_unlock(&input->mutex); return 0; }

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paul parsonspaul parsons7098.59%150.00%
jingoo hanjingoo han11.41%150.00%
Total71100.00%2100.00%


static int __maybe_unused navpoint_resume(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct navpoint *navpoint = platform_get_drvdata(pdev); struct input_dev *input = navpoint->input; mutex_lock(&input->mutex); if (input->users) navpoint_up(navpoint); mutex_unlock(&input->mutex); return 0; }

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paul parsonspaul parsons7098.59%150.00%
jingoo hanjingoo han11.41%150.00%
Total71100.00%2100.00%

static SIMPLE_DEV_PM_OPS(navpoint_pm_ops, navpoint_suspend, navpoint_resume); static struct platform_driver navpoint_driver = { .probe = navpoint_probe, .remove = navpoint_remove, .driver = { .name = "navpoint", .pm = &navpoint_pm_ops, }, }; module_platform_driver(navpoint_driver); MODULE_AUTHOR("Paul Parsons <lost.distance@yahoo.com>"); MODULE_DESCRIPTION("Synaptics NavPoint (PXA27x SSP/SPI) driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:navpoint");

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paul parsonspaul parsons164899.82%133.33%
jingoo hanjingoo han20.12%133.33%
lars-peter clausenlars-peter clausen10.06%133.33%
Total1651100.00%3100.00%
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