/* Copyright (c) 2009-2011, Code Aurora Forum. All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 and * only version 2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include <linux/module.h> #include <linux/platform_device.h> #include <linux/kernel.h> #include <linux/interrupt.h> #include <linux/slab.h> #include <linux/input.h> #include <linux/bitops.h> #include <linux/delay.h> #include <linux/mutex.h> #include <linux/mfd/pm8xxx/core.h> #include <linux/mfd/pm8xxx/gpio.h> #include <linux/input/pmic8xxx-keypad.h> #define PM8XXX_MAX_ROWS 18 #define PM8XXX_MAX_COLS 8 #define PM8XXX_ROW_SHIFT 3 #define PM8XXX_MATRIX_MAX_SIZE (PM8XXX_MAX_ROWS * PM8XXX_MAX_COLS) #define PM8XXX_MIN_ROWS 5 #define PM8XXX_MIN_COLS 5 #define MAX_SCAN_DELAY 128 #define MIN_SCAN_DELAY 1 /* in nanoseconds */ #define MAX_ROW_HOLD_DELAY 122000 #define MIN_ROW_HOLD_DELAY 30500 #define MAX_DEBOUNCE_TIME 20 #define MIN_DEBOUNCE_TIME 5 #define KEYP_CTRL 0x148 #define KEYP_CTRL_EVNTS BIT(0) #define KEYP_CTRL_EVNTS_MASK 0x3 #define KEYP_CTRL_SCAN_COLS_SHIFT 5 #define KEYP_CTRL_SCAN_COLS_MIN 5 #define KEYP_CTRL_SCAN_COLS_BITS 0x3 #define KEYP_CTRL_SCAN_ROWS_SHIFT 2 #define KEYP_CTRL_SCAN_ROWS_MIN 5 #define KEYP_CTRL_SCAN_ROWS_BITS 0x7 #define KEYP_CTRL_KEYP_EN BIT(7) #define KEYP_SCAN 0x149 #define KEYP_SCAN_READ_STATE BIT(0) #define KEYP_SCAN_DBOUNCE_SHIFT 1 #define KEYP_SCAN_PAUSE_SHIFT 3 #define KEYP_SCAN_ROW_HOLD_SHIFT 6 #define KEYP_TEST 0x14A #define KEYP_TEST_CLEAR_RECENT_SCAN BIT(6) #define KEYP_TEST_CLEAR_OLD_SCAN BIT(5) #define KEYP_TEST_READ_RESET BIT(4) #define KEYP_TEST_DTEST_EN BIT(3) #define KEYP_TEST_ABORT_READ BIT(0) #define KEYP_TEST_DBG_SELECT_SHIFT 1 /* bits of these registers represent * '0' for key press * '1' for key release */ #define KEYP_RECENT_DATA 0x14B #define KEYP_OLD_DATA 0x14C #define KEYP_CLOCK_FREQ 32768 /** * struct pmic8xxx_kp - internal keypad data structure * @pdata - keypad platform data pointer * @input - input device pointer for keypad * @key_sense_irq - key press/release irq number * @key_stuck_irq - key stuck notification irq number * @keycodes - array to hold the key codes * @dev - parent device pointer * @keystate - present key press/release state * @stuckstate - present state when key stuck irq * @ctrl_reg - control register value */ struct pmic8xxx_kp { const struct pm8xxx_keypad_platform_data *pdata; struct input_dev *input; int key_sense_irq; int key_stuck_irq; unsigned short keycodes[PM8XXX_MATRIX_MAX_SIZE]; struct device *dev; u16 keystate[PM8XXX_MAX_ROWS]; u16 stuckstate[PM8XXX_MAX_ROWS]; u8 ctrl_reg; }; static int pmic8xxx_kp_write_u8(struct pmic8xxx_kp *kp, u8 data, u16 reg) { int rc; rc = pm8xxx_writeb(kp->dev->parent, reg, data); return rc; } static int pmic8xxx_kp_read(struct pmic8xxx_kp *kp, u8 *data, u16 reg, unsigned num_bytes) { int rc; rc = pm8xxx_read_buf(kp->dev->parent, reg, data, num_bytes); return rc; } static int pmic8xxx_kp_read_u8(struct pmic8xxx_kp *kp, u8 *data, u16 reg) { int rc; rc = pmic8xxx_kp_read(kp, data, reg, 1); return rc; } static u8 pmic8xxx_col_state(struct pmic8xxx_kp *kp, u8 col) { /* all keys pressed on that particular row? */ if (col == 0x00) return 1 << kp->pdata->num_cols; else return col & ((1 << kp->pdata->num_cols) - 1); } /* * Synchronous read protocol for RevB0 onwards: * * 1. Write '1' to ReadState bit in KEYP_SCAN register * 2. Wait 2*32KHz clocks, so that HW can successfully enter read mode * synchronously * 3. Read rows in old array first if events are more than one * 4. Read rows in recent array * 5. Wait 4*32KHz clocks * 6. Write '0' to ReadState bit of KEYP_SCAN register so that hw can * synchronously exit read mode. */ static int pmic8xxx_chk_sync_read(struct pmic8xxx_kp *kp) { int rc; u8 scan_val; rc = pmic8xxx_kp_read_u8(kp, &scan_val, KEYP_SCAN); if (rc < 0) { dev_err(kp->dev, "Error reading KEYP_SCAN reg, rc=%d\n", rc); return rc; } scan_val |= 0x1; rc = pmic8xxx_kp_write_u8(kp, scan_val, KEYP_SCAN); if (rc < 0) { dev_err(kp->dev, "Error writing KEYP_SCAN reg, rc=%d\n", rc); return rc; } /* 2 * 32KHz clocks */ udelay((2 * DIV_ROUND_UP(USEC_PER_SEC, KEYP_CLOCK_FREQ)) + 1); return rc; } static int pmic8xxx_kp_read_data(struct pmic8xxx_kp *kp, u16 *state, u16 data_reg, int read_rows) { int rc, row; u8 new_data[PM8XXX_MAX_ROWS]; rc = pmic8xxx_kp_read(kp, new_data, data_reg, read_rows); if (rc) return rc; for (row = 0; row < kp->pdata->num_rows; row++) { dev_dbg(kp->dev, "new_data[%d] = %d\n", row, new_data[row]); state[row] = pmic8xxx_col_state(kp, new_data[row]); } return rc; } static int pmic8xxx_kp_read_matrix(struct pmic8xxx_kp *kp, u16 *new_state, u16 *old_state) { int rc, read_rows; u8 scan_val; if (kp->pdata->num_rows < PM8XXX_MIN_ROWS) read_rows = PM8XXX_MIN_ROWS; else read_rows = kp->pdata->num_rows; pmic8xxx_chk_sync_read(kp); if (old_state) { rc = pmic8xxx_kp_read_data(kp, old_state, KEYP_OLD_DATA, read_rows); if (rc < 0) { dev_err(kp->dev, "Error reading KEYP_OLD_DATA, rc=%d\n", rc); return rc; } } rc = pmic8xxx_kp_read_data(kp, new_state, KEYP_RECENT_DATA, read_rows); if (rc < 0) { dev_err(kp->dev, "Error reading KEYP_RECENT_DATA, rc=%d\n", rc); return rc; } /* 4 * 32KHz clocks */ udelay((4 * DIV_ROUND_UP(USEC_PER_SEC, KEYP_CLOCK_FREQ)) + 1); rc = pmic8xxx_kp_read_u8(kp, &scan_val, KEYP_SCAN); if (rc < 0) { dev_err(kp->dev, "Error reading KEYP_SCAN reg, rc=%d\n", rc); return rc; } scan_val &= 0xFE; rc = pmic8xxx_kp_write_u8(kp, scan_val, KEYP_SCAN); if (rc < 0) dev_err(kp->dev, "Error writing KEYP_SCAN reg, rc=%d\n", rc); return rc; } static void __pmic8xxx_kp_scan_matrix(struct pmic8xxx_kp *kp, u16 *new_state, u16 *old_state) { int row, col, code; for (row = 0; row < kp->pdata->num_rows; row++) { int bits_changed = new_state[row] ^ old_state[row]; if (!bits_changed) continue; for (col = 0; col < kp->pdata->num_cols; col++) { if (!(bits_changed & (1 << col))) continue; dev_dbg(kp->dev, "key [%d:%d] %s\n", row, col, !(new_state[row] & (1 << col)) ? "pressed" : "released"); code = MATRIX_SCAN_CODE(row, col, PM8XXX_ROW_SHIFT); input_event(kp->input, EV_MSC, MSC_SCAN, code); input_report_key(kp->input, kp->keycodes[code], !(new_state[row] & (1 << col))); input_sync(kp->input); } } } static bool pmic8xxx_detect_ghost_keys(struct pmic8xxx_kp *kp, u16 *new_state) { int row, found_first = -1; u16 check, row_state; check = 0; for (row = 0; row < kp->pdata->num_rows; row++) { row_state = (~new_state[row]) & ((1 << kp->pdata->num_cols) - 1); if (hweight16(row_state) > 1) { if (found_first == -1) found_first = row; if (check & row_state) { dev_dbg(kp->dev, "detected ghost key on row[%d]" " and row[%d]\n", found_first, row); return true; } } check |= row_state; } return false; } static int pmic8xxx_kp_scan_matrix(struct pmic8xxx_kp *kp, unsigned int events) { u16 new_state[PM8XXX_MAX_ROWS]; u16 old_state[PM8XXX_MAX_ROWS]; int rc; switch (events) { case 0x1: rc = pmic8xxx_kp_read_matrix(kp, new_state, NULL); if (rc < 0) return rc; /* detecting ghost key is not an error */ if (pmic8xxx_detect_ghost_keys(kp, new_state)) return 0; __pmic8xxx_kp_scan_matrix(kp, new_state, kp->keystate); memcpy(kp->keystate, new_state, sizeof(new_state)); break; case 0x3: /* two events - eventcounter is gray-coded */ rc = pmic8xxx_kp_read_matrix(kp, new_state, old_state); if (rc < 0) return rc; __pmic8xxx_kp_scan_matrix(kp, old_state, kp->keystate); __pmic8xxx_kp_scan_matrix(kp, new_state, old_state); memcpy(kp->keystate, new_state, sizeof(new_state)); break; case 0x2: dev_dbg(kp->dev, "Some key events were lost\n"); rc = pmic8xxx_kp_read_matrix(kp, new_state, old_state); if (rc < 0) return rc; __pmic8xxx_kp_scan_matrix(kp, old_state, kp->keystate); __pmic8xxx_kp_scan_matrix(kp, new_state, old_state); memcpy(kp->keystate, new_state, sizeof(new_state)); break; default: rc = -EINVAL; } return rc; } /* * NOTE: We are reading recent and old data registers blindly * whenever key-stuck interrupt happens, because events counter doesn't * get updated when this interrupt happens due to key stuck doesn't get * considered as key state change. * * We are not using old data register contents after they are being read * because it might report the key which was pressed before the key being stuck * as stuck key because it's pressed status is stored in the old data * register. */ static irqreturn_t pmic8xxx_kp_stuck_irq(int irq, void *data) { u16 new_state[PM8XXX_MAX_ROWS]; u16 old_state[PM8XXX_MAX_ROWS]; int rc; struct pmic8xxx_kp *kp = data; rc = pmic8xxx_kp_read_matrix(kp, new_state, old_state); if (rc < 0) { dev_err(kp->dev, "failed to read keypad matrix\n"); return IRQ_HANDLED; } __pmic8xxx_kp_scan_matrix(kp, new_state, kp->stuckstate); return IRQ_HANDLED; } static irqreturn_t pmic8xxx_kp_irq(int irq, void *data) { struct pmic8xxx_kp *kp = data; u8 ctrl_val, events; int rc; rc = pmic8xxx_kp_read(kp, &ctrl_val, KEYP_CTRL, 1); if (rc < 0) { dev_err(kp->dev, "failed to read keyp_ctrl register\n"); return IRQ_HANDLED; } events = ctrl_val & KEYP_CTRL_EVNTS_MASK; rc = pmic8xxx_kp_scan_matrix(kp, events); if (rc < 0) dev_err(kp->dev, "failed to scan matrix\n"); return IRQ_HANDLED; } static int pmic8xxx_kpd_init(struct pmic8xxx_kp *kp) { int bits, rc, cycles; u8 scan_val = 0, ctrl_val = 0; static const u8 row_bits[] = { 0, 1, 2, 3, 4, 4, 5, 5, 6, 6, 6, 7, 7, 7, }; /* Find column bits */ if (kp->pdata->num_cols < KEYP_CTRL_SCAN_COLS_MIN) bits = 0; else bits = kp->pdata->num_cols - KEYP_CTRL_SCAN_COLS_MIN; ctrl_val = (bits & KEYP_CTRL_SCAN_COLS_BITS) << KEYP_CTRL_SCAN_COLS_SHIFT; /* Find row bits */ if (kp->pdata->num_rows < KEYP_CTRL_SCAN_ROWS_MIN) bits = 0; else bits = row_bits[kp->pdata->num_rows - KEYP_CTRL_SCAN_ROWS_MIN]; ctrl_val |= (bits << KEYP_CTRL_SCAN_ROWS_SHIFT); rc = pmic8xxx_kp_write_u8(kp, ctrl_val, KEYP_CTRL); if (rc < 0) { dev_err(kp->dev, "Error writing KEYP_CTRL reg, rc=%d\n", rc); return rc; } bits = (kp->pdata->debounce_ms / 5) - 1; scan_val |= (bits << KEYP_SCAN_DBOUNCE_SHIFT); bits = fls(kp->pdata->scan_delay_ms) - 1; scan_val |= (bits << KEYP_SCAN_PAUSE_SHIFT); /* Row hold time is a multiple of 32KHz cycles. */ cycles = (kp->pdata->row_hold_ns * KEYP_CLOCK_FREQ) / NSEC_PER_SEC; scan_val |= (cycles << KEYP_SCAN_ROW_HOLD_SHIFT); rc = pmic8xxx_kp_write_u8(kp, scan_val, KEYP_SCAN); if (rc) dev_err(kp->dev, "Error writing KEYP_SCAN reg, rc=%d\n", rc); return rc; } static int pmic8xxx_kp_config_gpio(int gpio_start, int num_gpios, struct pmic8xxx_kp *kp, struct pm_gpio *gpio_config) { int rc, i; if (gpio_start < 0 || num_gpios < 0) return -EINVAL; for (i = 0; i < num_gpios; i++) { rc = pm8xxx_gpio_config(gpio_start + i, gpio_config); if (rc) { dev_err(kp->dev, "%s: FAIL pm8xxx_gpio_config():" "for PM GPIO [%d] rc=%d.\n", __func__, gpio_start + i, rc); return rc; } } return 0; } static int pmic8xxx_kp_enable(struct pmic8xxx_kp *kp) { int rc; kp->ctrl_reg |= KEYP_CTRL_KEYP_EN; rc = pmic8xxx_kp_write_u8(kp, kp->ctrl_reg, KEYP_CTRL); if (rc < 0) dev_err(kp->dev, "Error writing KEYP_CTRL reg, rc=%d\n", rc); return rc; } static int pmic8xxx_kp_disable(struct pmic8xxx_kp *kp) { int rc; kp->ctrl_reg &= ~KEYP_CTRL_KEYP_EN; rc = pmic8xxx_kp_write_u8(kp, kp->ctrl_reg, KEYP_CTRL); if (rc < 0) return rc; return rc; } static int pmic8xxx_kp_open(struct input_dev *dev) { struct pmic8xxx_kp *kp = input_get_drvdata(dev); return pmic8xxx_kp_enable(kp); } static void pmic8xxx_kp_close(struct input_dev *dev) { struct pmic8xxx_kp *kp = input_get_drvdata(dev); pmic8xxx_kp_disable(kp); } /* * keypad controller should be initialized in the following sequence * only, otherwise it might get into FSM stuck state. * * - Initialize keypad control parameters, like no. of rows, columns, * timing values etc., * - configure rows and column gpios pull up/down. * - set irq edge type. * - enable the keypad controller. */ static int pmic8xxx_kp_probe(struct platform_device *pdev) { const struct pm8xxx_keypad_platform_data *pdata = dev_get_platdata(&pdev->dev); const struct matrix_keymap_data *keymap_data; struct pmic8xxx_kp *kp; int rc; u8 ctrl_val; struct pm_gpio kypd_drv = { .direction = PM_GPIO_DIR_OUT, .output_buffer = PM_GPIO_OUT_BUF_OPEN_DRAIN, .output_value = 0, .pull = PM_GPIO_PULL_NO, .vin_sel = PM_GPIO_VIN_S3, .out_strength = PM_GPIO_STRENGTH_LOW, .function = PM_GPIO_FUNC_1, .inv_int_pol = 1, }; struct pm_gpio kypd_sns = { .direction = PM_GPIO_DIR_IN, .pull = PM_GPIO_PULL_UP_31P5, .vin_sel = PM_GPIO_VIN_S3, .out_strength = PM_GPIO_STRENGTH_NO, .function = PM_GPIO_FUNC_NORMAL, .inv_int_pol = 1, }; if (!pdata || !pdata->num_cols || !pdata->num_rows || pdata->num_cols > PM8XXX_MAX_COLS || pdata->num_rows > PM8XXX_MAX_ROWS || pdata->num_cols < PM8XXX_MIN_COLS) { dev_err(&pdev->dev, "invalid platform data\n"); return -EINVAL; } if (!pdata->scan_delay_ms || pdata->scan_delay_ms > MAX_SCAN_DELAY || pdata->scan_delay_ms < MIN_SCAN_DELAY || !is_power_of_2(pdata->scan_delay_ms)) { dev_err(&pdev->dev, "invalid keypad scan time supplied\n"); return -EINVAL; } if (!pdata->row_hold_ns || pdata->row_hold_ns > MAX_ROW_HOLD_DELAY || pdata->row_hold_ns < MIN_ROW_HOLD_DELAY || ((pdata->row_hold_ns % MIN_ROW_HOLD_DELAY) != 0)) { dev_err(&pdev->dev, "invalid keypad row hold time supplied\n"); return -EINVAL; } if (!pdata->debounce_ms || ((pdata->debounce_ms % 5) != 0) || pdata->debounce_ms > MAX_DEBOUNCE_TIME || pdata->debounce_ms < MIN_DEBOUNCE_TIME) { dev_err(&pdev->dev, "invalid debounce time supplied\n"); return -EINVAL; } keymap_data = pdata->keymap_data; if (!keymap_data) { dev_err(&pdev->dev, "no keymap data supplied\n"); return -EINVAL; } kp = kzalloc(sizeof(*kp), GFP_KERNEL); if (!kp) return -ENOMEM; platform_set_drvdata(pdev, kp); kp->pdata = pdata; kp->dev = &pdev->dev; kp->input = input_allocate_device(); if (!kp->input) { dev_err(&pdev->dev, "unable to allocate input device\n"); rc = -ENOMEM; goto err_alloc_device; } kp->key_sense_irq = platform_get_irq(pdev, 0); if (kp->key_sense_irq < 0) { dev_err(&pdev->dev, "unable to get keypad sense irq\n"); rc = -ENXIO; goto err_get_irq; } kp->key_stuck_irq = platform_get_irq(pdev, 1); if (kp->key_stuck_irq < 0) { dev_err(&pdev->dev, "unable to get keypad stuck irq\n"); rc = -ENXIO; goto err_get_irq; } kp->input->name = pdata->input_name ? : "PMIC8XXX keypad"; kp->input->phys = pdata->input_phys_device ? : "pmic8xxx_keypad/input0"; kp->input->dev.parent = &pdev->dev; kp->input->id.bustype = BUS_I2C; kp->input->id.version = 0x0001; kp->input->id.product = 0x0001; kp->input->id.vendor = 0x0001; kp->input->open = pmic8xxx_kp_open; kp->input->close = pmic8xxx_kp_close; rc = matrix_keypad_build_keymap(keymap_data, NULL, PM8XXX_MAX_ROWS, PM8XXX_MAX_COLS, kp->keycodes, kp->input); if (rc) { dev_err(&pdev->dev, "failed to build keymap\n"); goto err_get_irq; } if (pdata->rep) __set_bit(EV_REP, kp->input->evbit); input_set_capability(kp->input, EV_MSC, MSC_SCAN); input_set_drvdata(kp->input, kp); /* initialize keypad state */ memset(kp->keystate, 0xff, sizeof(kp->keystate)); memset(kp->stuckstate, 0xff, sizeof(kp->stuckstate)); rc = pmic8xxx_kpd_init(kp); if (rc < 0) { dev_err(&pdev->dev, "unable to initialize keypad controller\n"); goto err_get_irq; } rc = pmic8xxx_kp_config_gpio(pdata->cols_gpio_start, pdata->num_cols, kp, &kypd_sns); if (rc < 0) { dev_err(&pdev->dev, "unable to configure keypad sense lines\n"); goto err_gpio_config; } rc = pmic8xxx_kp_config_gpio(pdata->rows_gpio_start, pdata->num_rows, kp, &kypd_drv); if (rc < 0) { dev_err(&pdev->dev, "unable to configure keypad drive lines\n"); goto err_gpio_config; } rc = request_any_context_irq(kp->key_sense_irq, pmic8xxx_kp_irq, IRQF_TRIGGER_RISING, "pmic-keypad", kp); if (rc < 0) { dev_err(&pdev->dev, "failed to request keypad sense irq\n"); goto err_get_irq; } rc = request_any_context_irq(kp->key_stuck_irq, pmic8xxx_kp_stuck_irq, IRQF_TRIGGER_RISING, "pmic-keypad-stuck", kp); if (rc < 0) { dev_err(&pdev->dev, "failed to request keypad stuck irq\n"); goto err_req_stuck_irq; } rc = pmic8xxx_kp_read_u8(kp, &ctrl_val, KEYP_CTRL); if (rc < 0) { dev_err(&pdev->dev, "failed to read KEYP_CTRL register\n"); goto err_pmic_reg_read; } kp->ctrl_reg = ctrl_val; rc = input_register_device(kp->input); if (rc < 0) { dev_err(&pdev->dev, "unable to register keypad input device\n"); goto err_pmic_reg_read; } device_init_wakeup(&pdev->dev, pdata->wakeup); return 0; err_pmic_reg_read: free_irq(kp->key_stuck_irq, kp); err_req_stuck_irq: free_irq(kp->key_sense_irq, kp); err_gpio_config: err_get_irq: input_free_device(kp->input); err_alloc_device: kfree(kp); return rc; } static int pmic8xxx_kp_remove(struct platform_device *pdev) { struct pmic8xxx_kp *kp = platform_get_drvdata(pdev); device_init_wakeup(&pdev->dev, 0); free_irq(kp->key_stuck_irq, kp); free_irq(kp->key_sense_irq, kp); input_unregister_device(kp->input); kfree(kp); return 0; } #ifdef CONFIG_PM_SLEEP static int pmic8xxx_kp_suspend(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct pmic8xxx_kp *kp = platform_get_drvdata(pdev); struct input_dev *input_dev = kp->input; if (device_may_wakeup(dev)) { enable_irq_wake(kp->key_sense_irq); } else { mutex_lock(&input_dev->mutex); if (input_dev->users) pmic8xxx_kp_disable(kp); mutex_unlock(&input_dev->mutex); } return 0; } static int pmic8xxx_kp_resume(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct pmic8xxx_kp *kp = platform_get_drvdata(pdev); struct input_dev *input_dev = kp->input; if (device_may_wakeup(dev)) { disable_irq_wake(kp->key_sense_irq); } else { mutex_lock(&input_dev->mutex); if (input_dev->users) pmic8xxx_kp_enable(kp); mutex_unlock(&input_dev->mutex); } return 0; } #endif static SIMPLE_DEV_PM_OPS(pm8xxx_kp_pm_ops, pmic8xxx_kp_suspend, pmic8xxx_kp_resume); static struct platform_driver pmic8xxx_kp_driver = { .probe = pmic8xxx_kp_probe, .remove = pmic8xxx_kp_remove, .driver = { .name = PM8XXX_KEYPAD_DEV_NAME, .owner = THIS_MODULE, .pm = &pm8xxx_kp_pm_ops, }, }; module_platform_driver(pmic8xxx_kp_driver); MODULE_LICENSE("GPL v2"); MODULE_DESCRIPTION("PMIC8XXX keypad driver"); MODULE_VERSION("1.0"); MODULE_ALIAS("platform:pmic8xxx_keypad"); MODULE_AUTHOR("Trilok Soni <tsoni@codeaurora.org>");