diff options
author | Andy Shevchenko <andriy.shevchenko@linux.intel.com> | 2017-04-04 20:25:22 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-04-08 17:48:20 +0200 |
commit | 00846a4425d373761c70cbe82cceb98d3d4da179 (patch) | |
tree | 38d8ecd3954282bb3caf0d1510eee861658ca311 /drivers/misc/arm-charlcd.c | |
parent | 51c1e9b554c996284d5d3bd44da829f41a49a21b (diff) | |
download | linux-00846a4425d373761c70cbe82cceb98d3d4da179.tar.bz2 |
auxdisplay: Move arm-charlcd.c to drivers/auxdisplay folder
It looks like arm-charlcd.c belongs to auxdisplay subsystem.
Move it to drivers/auxdisplay folder.
No functional changes intended.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/misc/arm-charlcd.c')
-rw-r--r-- | drivers/misc/arm-charlcd.c | 368 |
1 files changed, 0 insertions, 368 deletions
diff --git a/drivers/misc/arm-charlcd.c b/drivers/misc/arm-charlcd.c deleted file mode 100644 index b3176ee92b90..000000000000 --- a/drivers/misc/arm-charlcd.c +++ /dev/null @@ -1,368 +0,0 @@ -/* - * Driver for the on-board character LCD found on some ARM reference boards - * This is basically an Hitachi HD44780 LCD with a custom IP block to drive it - * http://en.wikipedia.org/wiki/HD44780_Character_LCD - * Currently it will just display the text "ARM Linux" and the linux version - * - * License terms: GNU General Public License (GPL) version 2 - * Author: Linus Walleij <triad@df.lth.se> - */ -#include <linux/init.h> -#include <linux/interrupt.h> -#include <linux/platform_device.h> -#include <linux/of.h> -#include <linux/completion.h> -#include <linux/delay.h> -#include <linux/io.h> -#include <linux/slab.h> -#include <linux/workqueue.h> -#include <generated/utsrelease.h> - -#define DRIVERNAME "arm-charlcd" -#define CHARLCD_TIMEOUT (msecs_to_jiffies(1000)) - -/* Offsets to registers */ -#define CHAR_COM 0x00U -#define CHAR_DAT 0x04U -#define CHAR_RD 0x08U -#define CHAR_RAW 0x0CU -#define CHAR_MASK 0x10U -#define CHAR_STAT 0x14U - -#define CHAR_RAW_CLEAR 0x00000000U -#define CHAR_RAW_VALID 0x00000100U - -/* Hitachi HD44780 display commands */ -#define HD_CLEAR 0x01U -#define HD_HOME 0x02U -#define HD_ENTRYMODE 0x04U -#define HD_ENTRYMODE_INCREMENT 0x02U -#define HD_ENTRYMODE_SHIFT 0x01U -#define HD_DISPCTRL 0x08U -#define HD_DISPCTRL_ON 0x04U -#define HD_DISPCTRL_CURSOR_ON 0x02U -#define HD_DISPCTRL_CURSOR_BLINK 0x01U -#define HD_CRSR_SHIFT 0x10U -#define HD_CRSR_SHIFT_DISPLAY 0x08U -#define HD_CRSR_SHIFT_DISPLAY_RIGHT 0x04U -#define HD_FUNCSET 0x20U -#define HD_FUNCSET_8BIT 0x10U -#define HD_FUNCSET_2_LINES 0x08U -#define HD_FUNCSET_FONT_5X10 0x04U -#define HD_SET_CGRAM 0x40U -#define HD_SET_DDRAM 0x80U -#define HD_BUSY_FLAG 0x80U - -/** - * @dev: a pointer back to containing device - * @phybase: the offset to the controller in physical memory - * @physize: the size of the physical page - * @virtbase: the offset to the controller in virtual memory - * @irq: reserved interrupt number - * @complete: completion structure for the last LCD command - */ -struct charlcd { - struct device *dev; - u32 phybase; - u32 physize; - void __iomem *virtbase; - int irq; - struct completion complete; - struct delayed_work init_work; -}; - -static irqreturn_t charlcd_interrupt(int irq, void *data) -{ - struct charlcd *lcd = data; - u8 status; - - status = readl(lcd->virtbase + CHAR_STAT) & 0x01; - /* Clear IRQ */ - writel(CHAR_RAW_CLEAR, lcd->virtbase + CHAR_RAW); - if (status) - complete(&lcd->complete); - else - dev_info(lcd->dev, "Spurious IRQ (%02x)\n", status); - return IRQ_HANDLED; -} - - -static void charlcd_wait_complete_irq(struct charlcd *lcd) -{ - int ret; - - ret = wait_for_completion_interruptible_timeout(&lcd->complete, - CHARLCD_TIMEOUT); - /* Disable IRQ after completion */ - writel(0x00, lcd->virtbase + CHAR_MASK); - - if (ret < 0) { - dev_err(lcd->dev, - "wait_for_completion_interruptible_timeout() " - "returned %d waiting for ready\n", ret); - return; - } - - if (ret == 0) { - dev_err(lcd->dev, "charlcd controller timed out " - "waiting for ready\n"); - return; - } -} - -static u8 charlcd_4bit_read_char(struct charlcd *lcd) -{ - u8 data; - u32 val; - int i; - - /* If we can, use an IRQ to wait for the data, else poll */ - if (lcd->irq >= 0) - charlcd_wait_complete_irq(lcd); - else { - i = 0; - val = 0; - while (!(val & CHAR_RAW_VALID) && i < 10) { - udelay(100); - val = readl(lcd->virtbase + CHAR_RAW); - i++; - } - - writel(CHAR_RAW_CLEAR, lcd->virtbase + CHAR_RAW); - } - msleep(1); - - /* Read the 4 high bits of the data */ - data = readl(lcd->virtbase + CHAR_RD) & 0xf0; - - /* - * The second read for the low bits does not trigger an IRQ - * so in this case we have to poll for the 4 lower bits - */ - i = 0; - val = 0; - while (!(val & CHAR_RAW_VALID) && i < 10) { - udelay(100); - val = readl(lcd->virtbase + CHAR_RAW); - i++; - } - writel(CHAR_RAW_CLEAR, lcd->virtbase + CHAR_RAW); - msleep(1); - - /* Read the 4 low bits of the data */ - data |= (readl(lcd->virtbase + CHAR_RD) >> 4) & 0x0f; - - return data; -} - -static bool charlcd_4bit_read_bf(struct charlcd *lcd) -{ - if (lcd->irq >= 0) { - /* - * If we'll use IRQs to wait for the busyflag, clear any - * pending flag and enable IRQ - */ - writel(CHAR_RAW_CLEAR, lcd->virtbase + CHAR_RAW); - init_completion(&lcd->complete); - writel(0x01, lcd->virtbase + CHAR_MASK); - } - readl(lcd->virtbase + CHAR_COM); - return charlcd_4bit_read_char(lcd) & HD_BUSY_FLAG ? true : false; -} - -static void charlcd_4bit_wait_busy(struct charlcd *lcd) -{ - int retries = 50; - - udelay(100); - while (charlcd_4bit_read_bf(lcd) && retries) - retries--; - if (!retries) - dev_err(lcd->dev, "timeout waiting for busyflag\n"); -} - -static void charlcd_4bit_command(struct charlcd *lcd, u8 cmd) -{ - u32 cmdlo = (cmd << 4) & 0xf0; - u32 cmdhi = (cmd & 0xf0); - - writel(cmdhi, lcd->virtbase + CHAR_COM); - udelay(10); - writel(cmdlo, lcd->virtbase + CHAR_COM); - charlcd_4bit_wait_busy(lcd); -} - -static void charlcd_4bit_char(struct charlcd *lcd, u8 ch) -{ - u32 chlo = (ch << 4) & 0xf0; - u32 chhi = (ch & 0xf0); - - writel(chhi, lcd->virtbase + CHAR_DAT); - udelay(10); - writel(chlo, lcd->virtbase + CHAR_DAT); - charlcd_4bit_wait_busy(lcd); -} - -static void charlcd_4bit_print(struct charlcd *lcd, int line, const char *str) -{ - u8 offset; - int i; - - /* - * We support line 0, 1 - * Line 1 runs from 0x00..0x27 - * Line 2 runs from 0x28..0x4f - */ - if (line == 0) - offset = 0; - else if (line == 1) - offset = 0x28; - else - return; - - /* Set offset */ - charlcd_4bit_command(lcd, HD_SET_DDRAM | offset); - - /* Send string */ - for (i = 0; i < strlen(str) && i < 0x28; i++) - charlcd_4bit_char(lcd, str[i]); -} - -static void charlcd_4bit_init(struct charlcd *lcd) -{ - /* These commands cannot be checked with the busy flag */ - writel(HD_FUNCSET | HD_FUNCSET_8BIT, lcd->virtbase + CHAR_COM); - msleep(5); - writel(HD_FUNCSET | HD_FUNCSET_8BIT, lcd->virtbase + CHAR_COM); - udelay(100); - writel(HD_FUNCSET | HD_FUNCSET_8BIT, lcd->virtbase + CHAR_COM); - udelay(100); - /* Go to 4bit mode */ - writel(HD_FUNCSET, lcd->virtbase + CHAR_COM); - udelay(100); - /* - * 4bit mode, 2 lines, 5x8 font, after this the number of lines - * and the font cannot be changed until the next initialization sequence - */ - charlcd_4bit_command(lcd, HD_FUNCSET | HD_FUNCSET_2_LINES); - charlcd_4bit_command(lcd, HD_DISPCTRL | HD_DISPCTRL_ON); - charlcd_4bit_command(lcd, HD_ENTRYMODE | HD_ENTRYMODE_INCREMENT); - charlcd_4bit_command(lcd, HD_CLEAR); - charlcd_4bit_command(lcd, HD_HOME); - /* Put something useful in the display */ - charlcd_4bit_print(lcd, 0, "ARM Linux"); - charlcd_4bit_print(lcd, 1, UTS_RELEASE); -} - -static void charlcd_init_work(struct work_struct *work) -{ - struct charlcd *lcd = - container_of(work, struct charlcd, init_work.work); - - charlcd_4bit_init(lcd); -} - -static int __init charlcd_probe(struct platform_device *pdev) -{ - int ret; - struct charlcd *lcd; - struct resource *res; - - lcd = kzalloc(sizeof(struct charlcd), GFP_KERNEL); - if (!lcd) - return -ENOMEM; - - lcd->dev = &pdev->dev; - - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (!res) { - ret = -ENOENT; - goto out_no_resource; - } - lcd->phybase = res->start; - lcd->physize = resource_size(res); - - if (request_mem_region(lcd->phybase, lcd->physize, - DRIVERNAME) == NULL) { - ret = -EBUSY; - goto out_no_memregion; - } - - lcd->virtbase = ioremap(lcd->phybase, lcd->physize); - if (!lcd->virtbase) { - ret = -ENOMEM; - goto out_no_memregion; - } - - lcd->irq = platform_get_irq(pdev, 0); - /* If no IRQ is supplied, we'll survive without it */ - if (lcd->irq >= 0) { - if (request_irq(lcd->irq, charlcd_interrupt, 0, - DRIVERNAME, lcd)) { - ret = -EIO; - goto out_no_irq; - } - } - - platform_set_drvdata(pdev, lcd); - - /* - * Initialize the display in a delayed work, because - * it is VERY slow and would slow down the boot of the system. - */ - INIT_DELAYED_WORK(&lcd->init_work, charlcd_init_work); - schedule_delayed_work(&lcd->init_work, 0); - - dev_info(&pdev->dev, "initialized ARM character LCD at %08x\n", - lcd->phybase); - - return 0; - -out_no_irq: - iounmap(lcd->virtbase); -out_no_memregion: - release_mem_region(lcd->phybase, SZ_4K); -out_no_resource: - kfree(lcd); - return ret; -} - -static int charlcd_suspend(struct device *dev) -{ - struct platform_device *pdev = to_platform_device(dev); - struct charlcd *lcd = platform_get_drvdata(pdev); - - /* Power the display off */ - charlcd_4bit_command(lcd, HD_DISPCTRL); - return 0; -} - -static int charlcd_resume(struct device *dev) -{ - struct platform_device *pdev = to_platform_device(dev); - struct charlcd *lcd = platform_get_drvdata(pdev); - - /* Turn the display back on */ - charlcd_4bit_command(lcd, HD_DISPCTRL | HD_DISPCTRL_ON); - return 0; -} - -static const struct dev_pm_ops charlcd_pm_ops = { - .suspend = charlcd_suspend, - .resume = charlcd_resume, -}; - -static const struct of_device_id charlcd_match[] = { - { .compatible = "arm,versatile-lcd", }, - {} -}; - -static struct platform_driver charlcd_driver = { - .driver = { - .name = DRIVERNAME, - .pm = &charlcd_pm_ops, - .suppress_bind_attrs = true, - .of_match_table = of_match_ptr(charlcd_match), - }, -}; -builtin_platform_driver_probe(charlcd_driver, charlcd_probe); |