Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932275AbcLNH4P (ORCPT ); Wed, 14 Dec 2016 02:56:15 -0500 Received: from mail-pg0-f48.google.com ([74.125.83.48]:34934 "EHLO mail-pg0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932203AbcLNH4L (ORCPT ); Wed, 14 Dec 2016 02:56:11 -0500 From: Jaghathiswari Rankappagounder Natarajan To: openbmc@lists.ozlabs.org, robh+dt@kernel.org, mark.rutland@arm.com, linux@armlinux.org.uk, arnd@arndb.de, gregkh@linuxfoundation.org Cc: Jaghathiswari Rankappagounder Natarajan , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, joel@jms.id.au Subject: [PATCH linux v1 3/4] drivers: misc: Platform driver for seven segment display support Date: Tue, 13 Dec 2016 23:55:03 -0800 Message-Id: <1481702104-8617-4-git-send-email-jaghu@google.com> X-Mailer: git-send-email 2.8.0.rc3.226.g39d4020 In-Reply-To: <1481702104-8617-1-git-send-email-jaghu@google.com> References: <1481702104-8617-1-git-send-email-jaghu@google.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7423 Lines: 254 Platform device driver which provides an API for displaying on two 7-segment displays, and implements the required bit-banging. The hardware assumed is 74HC164 wired to two 7-segment displays. Signed-off-by: Jaghathiswari Rankappagounder Natarajan --- drivers/misc/Kconfig | 8 ++ drivers/misc/Makefile | 1 + drivers/misc/seven_seg_gpio.c | 206 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 215 insertions(+) create mode 100644 drivers/misc/seven_seg_gpio.c diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig index a21aec1..6508108 100644 --- a/drivers/misc/Kconfig +++ b/drivers/misc/Kconfig @@ -812,6 +812,14 @@ config PANEL_BOOT_MESSAGE An empty message will only clear the display at driver init time. Any other printf()-formatted message is valid with newline and escape codes. +config SEVEN_SEGMENT_GPIO + tristate "Platform driver to update seven segment display" + depends on SEVEN_SEGMENT_DISPLAY + help + Platform device driver which provides an API for displaying on two + 7-segment displays, and implements the required bit-banging. + The hardware assumed is 74HC164 wired to two 7-segment displays. + source "drivers/misc/c2port/Kconfig" source "drivers/misc/eeprom/Kconfig" source "drivers/misc/cb710/Kconfig" diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile index c2defbd..d9c0d20 100644 --- a/drivers/misc/Makefile +++ b/drivers/misc/Makefile @@ -58,3 +58,4 @@ obj-$(CONFIG_VEXPRESS_SYSCFG) += vexpress-syscfg.o obj-$(CONFIG_CXL_BASE) += cxl/ obj-$(CONFIG_SEVEN_SEGMENT_DISPLAY) += seven_seg_disp.o obj-$(CONFIG_PANEL) += panel.o +obj-$(CONFIG_SEVEN_SEGMENT_GPIO) += seven_seg_gpio.o diff --git a/drivers/misc/seven_seg_gpio.c b/drivers/misc/seven_seg_gpio.c new file mode 100644 index 0000000..3dcb903 --- /dev/null +++ b/drivers/misc/seven_seg_gpio.c @@ -0,0 +1,206 @@ +/* + * Copyright (C) 2016 Google, Inc + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 or later as + * published by the Free Software Foundation. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "seven_seg_disp.h" + +#define DELAY_INTVL_US 1 + +#define CLOCK_GPIO_NAME "clock" +#define DATA_GPIO_NAME "data" +#define CLEAR_GPIO_NAME "clear" + +struct seven_seg_gpio_info { + u16 curr_disp_value; + u16 refresh_interval; + struct timer_list update_timer; + struct gpio_desc *clock_gpio; + struct gpio_desc *data_gpio; + struct gpio_desc *clear_gpio; +}; + +static void update_seven_seg_gpio_data(struct device *dev, u16 data) +{ + struct platform_device *pdev; + struct seven_seg_gpio_info *gpio_info; + + pdev = container_of(dev, struct platform_device, dev); + if (pdev == NULL) { + pr_err("invalid NULL platform_device\n"); + return; + } + + gpio_info = platform_get_drvdata(pdev); + if (gpio_info == NULL) { + pr_err("invalid NULL gpio_info\n"); + return; + } + + gpio_info->curr_disp_value = data; +} + +static void clear_seven_seg_gpio_data(struct device *dev, u16 data) +{ + struct platform_device *pdev; + struct seven_seg_gpio_info *gpio_info; + + pdev = container_of(dev, struct platform_device, dev); + if (pdev == NULL) { + pr_err("invalid NULL platform_device\n"); + return; + } + + gpio_info = platform_get_drvdata(pdev); + if (gpio_info == NULL) { + pr_err("invalid NULL gpio_info\n"); + return; + } + + gpio_info->curr_disp_value = 0; +} + +static void send_seven_seg_gpio_data(u16 disp_data, + struct seven_seg_gpio_info *gpio_info) +{ + int i; + + gpiod_set_value(gpio_info->clear_gpio, 0); + udelay(DELAY_INTVL_US); + gpiod_set_value(gpio_info->clear_gpio, 1); + udelay(DELAY_INTVL_US); + + for (i = 0; i < 16; i++) { + if (disp_data & 0x01) + gpiod_set_value(gpio_info->data_gpio, 1); + else + gpiod_set_value(gpio_info->data_gpio, 0); + + udelay(DELAY_INTVL_US); + + gpiod_set_value(gpio_info->clock_gpio, 0); + udelay(DELAY_INTVL_US); + gpiod_set_value(gpio_info->clock_gpio, 1); + udelay(DELAY_INTVL_US); + + disp_data >>= 1; + } +} + +static void disp_refresh_timer_handler(unsigned long data) +{ + u16 disp_data; + struct seven_seg_gpio_info *gpio_info = + (struct seven_seg_gpio_info *)data; + disp_data = gpio_info->curr_disp_value; + + send_seven_seg_gpio_data(disp_data, gpio_info); + mod_timer(&gpio_info->update_timer, + jiffies + msecs_to_jiffies(gpio_info->refresh_interval)); +} + +static const struct of_device_id of_seven_seg_gpio_match[] = { + { .compatible = "seven-seg-gpio-dev" }, + {}, +}; + +MODULE_DEVICE_TABLE(of, of_seven_seg_gpio_match); + +static int seven_seg_gpio_probe(struct platform_device *pdev) +{ + u16 interval; + int result; + struct seven_seg_gpio_info *gpio_info; + struct device *dev = &pdev->dev; + struct seven_seg_disp_dev *disp_dev; + + gpio_info = devm_kzalloc(dev, + sizeof(struct seven_seg_gpio_info), + GFP_KERNEL); + if (gpio_info == NULL) + return -ENOMEM; + + /* Requesting the clock gpio */ + gpio_info->clock_gpio = devm_gpiod_get(dev, CLOCK_GPIO_NAME, + GPIOD_OUT_HIGH); + if (IS_ERR(gpio_info->clock_gpio)) + return PTR_ERR(gpio_info->clock_gpio); + + /* Requesting the data gpio */ + gpio_info->data_gpio = devm_gpiod_get(dev, DATA_GPIO_NAME, + GPIOD_OUT_HIGH); + if (IS_ERR(gpio_info->data_gpio)) + return PTR_ERR(gpio_info->data_gpio); + + /* Requesting the clear gpio */ + gpio_info->clear_gpio = devm_gpiod_get(dev, CLEAR_GPIO_NAME, + GPIOD_OUT_HIGH); + if (IS_ERR(gpio_info->clear_gpio)) + return PTR_ERR(gpio_info->clear_gpio); + + result = of_property_read_u16(pdev->dev.of_node, + "refresh-interval-ms", &interval); + gpio_info->refresh_interval = result ? DEFAULT_REFRESH_INTERVAL_MS : + interval; + + /* Start timer to update seven segment display every second */ + setup_timer(&gpio_info->update_timer, disp_refresh_timer_handler, + (unsigned long)gpio_info); + result = mod_timer(&gpio_info->update_timer, + jiffies + + msecs_to_jiffies(gpio_info->refresh_interval)); + if (result) + return result; + + gpio_info->curr_disp_value = 0; + + platform_set_drvdata(pdev, gpio_info); + + disp_dev = devm_kzalloc(dev, sizeof(struct seven_seg_disp_dev), + GFP_KERNEL); + disp_dev->parent = *dev; + seven_seg_setup_cdev(disp_dev, &update_seven_seg_gpio_data); + return 0; +} + +static int seven_seg_gpio_remove(struct platform_device *pdev) +{ + struct seven_seg_gpio_info *gpio_info = platform_get_drvdata(pdev); + struct seven_seg_disp_dev *disp_dev = + container_of(&pdev->dev, + struct seven_seg_disp_dev, parent); + seven_seg_rem_cdev(disp_dev); + del_timer_sync(&gpio_info->update_timer); + platform_set_drvdata(pdev, NULL); + return 0; +} + +static struct platform_driver seven_seg_gpio_driver = { + .probe = seven_seg_gpio_probe, + .remove = seven_seg_gpio_remove, + .driver = { + .name = "seven-seg-gpio", + .of_match_table = of_seven_seg_gpio_match, + }, +}; + +module_platform_driver(seven_seg_gpio_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Jaghathiswari Rankappagounder Natarajan "); +MODULE_DESCRIPTION("Seven segment display driver using GPIO config"); -- 2.8.0.rc3.226.g39d4020