diff options
Diffstat (limited to 'drivers/input/touchscreen/zylonite-wm97xx.c')
| -rw-r--r-- | drivers/input/touchscreen/zylonite-wm97xx.c | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/zylonite-wm97xx.c b/drivers/input/touchscreen/zylonite-wm97xx.c new file mode 100644 index 000000000..a70fe4abe --- /dev/null +++ b/drivers/input/touchscreen/zylonite-wm97xx.c @@ -0,0 +1,220 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * zylonite-wm97xx.c -- Zylonite Continuous Touch screen driver + * + * Copyright 2004, 2007, 2008 Wolfson Microelectronics PLC. + * Author: Mark Brown <broonie@opensource.wolfsonmicro.com> + * Parts Copyright : Ian Molton <spyro@f2s.com> + * Andrew Zabolotny <zap@homelink.ru> + * + * Notes: + * This is a wm97xx extended touch driver supporting interrupt driven + * and continuous operation on Marvell Zylonite development systems + * (which have a WM9713 on board). + */ + +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/kernel.h> +#include <linux/delay.h> +#include <linux/gpio/consumer.h> +#include <linux/irq.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/soc/pxa/cpu.h> +#include <linux/wm97xx.h> + +#include <sound/pxa2xx-lib.h> + +struct continuous { + u16 id; /* codec id */ + u8 code; /* continuous code */ + u8 reads; /* number of coord reads per read cycle */ + u32 speed; /* number of coords per second */ +}; + +#define WM_READS(sp) ((sp / HZ) + 1) + +static const struct continuous cinfo[] = { + { WM9713_ID2, 0, WM_READS(94), 94 }, + { WM9713_ID2, 1, WM_READS(120), 120 }, + { WM9713_ID2, 2, WM_READS(154), 154 }, + { WM9713_ID2, 3, WM_READS(188), 188 }, +}; + +/* continuous speed index */ +static int sp_idx; + +/* + * Pen sampling frequency (Hz) in continuous mode. + */ +static int cont_rate = 200; +module_param(cont_rate, int, 0); +MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)"); + +/* + * Pressure readback. + * + * Set to 1 to read back pen down pressure + */ +static int pressure; +module_param(pressure, int, 0); +MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)"); + +/* + * AC97 touch data slot. + * + * Touch screen readback data ac97 slot + */ +static int ac97_touch_slot = 5; +module_param(ac97_touch_slot, int, 0); +MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number"); + + +/* flush AC97 slot 5 FIFO machines */ +static void wm97xx_acc_pen_up(struct wm97xx *wm) +{ + int i; + + msleep(1); + + for (i = 0; i < 16; i++) + pxa2xx_ac97_read_modr(); +} + +static int wm97xx_acc_pen_down(struct wm97xx *wm) +{ + u16 x, y, p = 0x100 | WM97XX_ADCSEL_PRES; + int reads = 0; + static u16 last, tries; + + /* When the AC97 queue has been drained we need to allow time + * to buffer up samples otherwise we end up spinning polling + * for samples. The controller can't have a suitably low + * threshold set to use the notifications it gives. + */ + msleep(1); + + if (tries > 5) { + tries = 0; + return RC_PENUP; + } + + x = pxa2xx_ac97_read_modr(); + if (x == last) { + tries++; + return RC_AGAIN; + } + last = x; + do { + if (reads) + x = pxa2xx_ac97_read_modr(); + y = pxa2xx_ac97_read_modr(); + if (pressure) + p = pxa2xx_ac97_read_modr(); + + dev_dbg(wm->dev, "Raw coordinates: x=%x, y=%x, p=%x\n", + x, y, p); + + /* are samples valid */ + if ((x & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_X || + (y & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_Y || + (p & WM97XX_ADCSEL_MASK) != WM97XX_ADCSEL_PRES) + goto up; + + /* coordinate is good */ + tries = 0; + input_report_abs(wm->input_dev, ABS_X, x & 0xfff); + input_report_abs(wm->input_dev, ABS_Y, y & 0xfff); + input_report_abs(wm->input_dev, ABS_PRESSURE, p & 0xfff); + input_report_key(wm->input_dev, BTN_TOUCH, (p != 0)); + input_sync(wm->input_dev); + reads++; + } while (reads < cinfo[sp_idx].reads); +up: + return RC_PENDOWN | RC_AGAIN; +} + +static int wm97xx_acc_startup(struct wm97xx *wm) +{ + int idx; + + /* check we have a codec */ + if (wm->ac97 == NULL) + return -ENODEV; + + /* Go you big red fire engine */ + for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) { + if (wm->id != cinfo[idx].id) + continue; + sp_idx = idx; + if (cont_rate <= cinfo[idx].speed) + break; + } + wm->acc_rate = cinfo[sp_idx].code; + wm->acc_slot = ac97_touch_slot; + dev_info(wm->dev, + "zylonite accelerated touchscreen driver, %d samples/sec\n", + cinfo[sp_idx].speed); + + return 0; +} + +static struct wm97xx_mach_ops zylonite_mach_ops = { + .acc_enabled = 1, + .acc_pen_up = wm97xx_acc_pen_up, + .acc_pen_down = wm97xx_acc_pen_down, + .acc_startup = wm97xx_acc_startup, + .irq_gpio = WM97XX_GPIO_2, +}; + +static int zylonite_wm97xx_probe(struct platform_device *pdev) +{ + struct wm97xx *wm = platform_get_drvdata(pdev); + struct gpio_desc *gpio_touch_irq; + int err; + + gpio_touch_irq = devm_gpiod_get(&pdev->dev, "touch", GPIOD_IN); + err = PTR_ERR_OR_ZERO(gpio_touch_irq); + if (err) { + dev_err(&pdev->dev, "Cannot get irq gpio: %d\n", err); + return err; + } + + wm->pen_irq = gpiod_to_irq(gpio_touch_irq); + irq_set_irq_type(wm->pen_irq, IRQ_TYPE_EDGE_BOTH); + + wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN, + WM97XX_GPIO_POL_HIGH, + WM97XX_GPIO_STICKY, + WM97XX_GPIO_WAKE); + wm97xx_config_gpio(wm, WM97XX_GPIO_2, WM97XX_GPIO_OUT, + WM97XX_GPIO_POL_HIGH, + WM97XX_GPIO_NOTSTICKY, + WM97XX_GPIO_NOWAKE); + + return wm97xx_register_mach_ops(wm, &zylonite_mach_ops); +} + +static int zylonite_wm97xx_remove(struct platform_device *pdev) +{ + struct wm97xx *wm = platform_get_drvdata(pdev); + + wm97xx_unregister_mach_ops(wm); + + return 0; +} + +static struct platform_driver zylonite_wm97xx_driver = { + .probe = zylonite_wm97xx_probe, + .remove = zylonite_wm97xx_remove, + .driver = { + .name = "wm97xx-touch", + }, +}; +module_platform_driver(zylonite_wm97xx_driver); + +/* Module information */ +MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); +MODULE_DESCRIPTION("wm97xx continuous touch driver for Zylonite"); +MODULE_LICENSE("GPL"); |