Back to home page

OSCL-LXR

 
 

    


0001 // SPDX-License-Identifier: GPL-2.0+
0002 /*
0003  * Access to GPOs on TWL6040 chip
0004  *
0005  * Copyright (C) 2012 Texas Instruments, Inc.
0006  *
0007  * Authors:
0008  *  Sergio Aguirre <saaguirre@ti.com>
0009  *  Peter Ujfalusi <peter.ujfalusi@ti.com>
0010  */
0011 
0012 #include <linux/module.h>
0013 #include <linux/init.h>
0014 #include <linux/kthread.h>
0015 #include <linux/irq.h>
0016 #include <linux/gpio/driver.h>
0017 #include <linux/platform_device.h>
0018 #include <linux/bitops.h>
0019 #include <linux/of.h>
0020 
0021 #include <linux/mfd/twl6040.h>
0022 
0023 static int twl6040gpo_get(struct gpio_chip *chip, unsigned offset)
0024 {
0025     struct twl6040 *twl6040 = dev_get_drvdata(chip->parent->parent);
0026     int ret = 0;
0027 
0028     ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
0029     if (ret < 0)
0030         return ret;
0031 
0032     return !!(ret & BIT(offset));
0033 }
0034 
0035 static int twl6040gpo_get_direction(struct gpio_chip *chip, unsigned offset)
0036 {
0037     return GPIO_LINE_DIRECTION_OUT;
0038 }
0039 
0040 static int twl6040gpo_direction_out(struct gpio_chip *chip, unsigned offset,
0041                     int value)
0042 {
0043     /* This only drives GPOs, and can't change direction */
0044     return 0;
0045 }
0046 
0047 static void twl6040gpo_set(struct gpio_chip *chip, unsigned offset, int value)
0048 {
0049     struct twl6040 *twl6040 = dev_get_drvdata(chip->parent->parent);
0050     int ret;
0051     u8 gpoctl;
0052 
0053     ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
0054     if (ret < 0)
0055         return;
0056 
0057     if (value)
0058         gpoctl = ret | BIT(offset);
0059     else
0060         gpoctl = ret & ~BIT(offset);
0061 
0062     twl6040_reg_write(twl6040, TWL6040_REG_GPOCTL, gpoctl);
0063 }
0064 
0065 static struct gpio_chip twl6040gpo_chip = {
0066     .label          = "twl6040",
0067     .owner          = THIS_MODULE,
0068     .get            = twl6040gpo_get,
0069     .direction_output   = twl6040gpo_direction_out,
0070     .get_direction      = twl6040gpo_get_direction,
0071     .set            = twl6040gpo_set,
0072     .can_sleep      = true,
0073 };
0074 
0075 /*----------------------------------------------------------------------*/
0076 
0077 static int gpo_twl6040_probe(struct platform_device *pdev)
0078 {
0079     struct device *twl6040_core_dev = pdev->dev.parent;
0080     struct twl6040 *twl6040 = dev_get_drvdata(twl6040_core_dev);
0081     int ret;
0082 
0083     device_set_node(&pdev->dev, dev_fwnode(pdev->dev.parent));
0084 
0085     twl6040gpo_chip.base = -1;
0086 
0087     if (twl6040_get_revid(twl6040) < TWL6041_REV_ES2_0)
0088         twl6040gpo_chip.ngpio = 3; /* twl6040 have 3 GPO */
0089     else
0090         twl6040gpo_chip.ngpio = 1; /* twl6041 have 1 GPO */
0091 
0092     twl6040gpo_chip.parent = &pdev->dev;
0093 
0094     ret = devm_gpiochip_add_data(&pdev->dev, &twl6040gpo_chip, NULL);
0095     if (ret < 0) {
0096         dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret);
0097         twl6040gpo_chip.ngpio = 0;
0098     }
0099 
0100     return ret;
0101 }
0102 
0103 /* Note:  this hardware lives inside an I2C-based multi-function device. */
0104 MODULE_ALIAS("platform:twl6040-gpo");
0105 
0106 static struct platform_driver gpo_twl6040_driver = {
0107     .driver = {
0108         .name   = "twl6040-gpo",
0109     },
0110     .probe      = gpo_twl6040_probe,
0111 };
0112 
0113 module_platform_driver(gpo_twl6040_driver);
0114 
0115 MODULE_AUTHOR("Texas Instruments, Inc.");
0116 MODULE_DESCRIPTION("GPO interface for TWL6040");
0117 MODULE_LICENSE("GPL");