lcd_dma.c

Go to the documentation of this file.

/*
 * linux/arch/arm/mach-omap1/lcd_dma.c
 *
 * Extracted from arch/arm/plat-omap/dma.c
 * Copyright (C) 2003 - 2008 Nokia Corporation
 * Author: Juha Yrjölä <[email protected]>
 * DMA channel linking for 1610 by Samuel Ortiz <[email protected]>
 * Graphics DMA and LCD DMA graphics tranformations
 * by Imre Deak <[email protected]>
 * OMAP2/3 support Copyright (C) 2004-2007 Texas Instruments, Inc.
 * Merged to support both OMAP1 and OMAP2 by Tony Lindgren <[email protected]>
 * Some functions based on earlier dma-omap.c Copyright (C) 2001 RidgeRun, Inc.
 *
 * Copyright (C) 2009 Texas Instruments
 * Added OMAP4 support - Santosh Shilimkar <[email protected]>
 *
 * Support functions for the OMAP internal DMA channels.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/io.h>

#include <plat/dma.h>

#include <mach/hardware.h>
#include <mach/lcdc.h>

int omap_lcd_dma_running(void)
{
    /*
     * On OMAP1510, internal LCD controller will start the transfer
     * when it gets enabled, so assume DMA running if LCD enabled.
     */
    if (cpu_is_omap15xx())
        if (omap_readw(OMAP_LCDC_CONTROL) & OMAP_LCDC_CTRL_LCD_EN)
            return 1;

    /* Check if LCD DMA is running */
    if (cpu_is_omap16xx())
        if (omap_readw(OMAP1610_DMA_LCD_CCR) & OMAP_DMA_CCR_EN)
            return 1;

    return 0;
}

static struct lcd_dma_info {
    spinlock_t lock;
    int reserved;
    void (*callback)(u16 status, void *data);
    void *cb_data;

    int active;
    unsigned long addr;
    int rotate, data_type, xres, yres;
    int vxres;
    int mirror;
    int xscale, yscale;
    int ext_ctrl;
    int src_port;
    int single_transfer;
} lcd_dma;

void omap_set_lcd_dma_b1(unsigned long addr, u16 fb_xres, u16 fb_yres,
             int data_type)
{
    lcd_dma.addr = addr;
    lcd_dma.data_type = data_type;
    lcd_dma.xres = fb_xres;
    lcd_dma.yres = fb_yres;
}
EXPORT_SYMBOL(omap_set_lcd_dma_b1);

void omap_set_lcd_dma_ext_controller(int external)
{
    lcd_dma.ext_ctrl = external;
}
EXPORT_SYMBOL(omap_set_lcd_dma_ext_controller);

void omap_set_lcd_dma_single_transfer(int single)
{
    lcd_dma.single_transfer = single;
}
EXPORT_SYMBOL(omap_set_lcd_dma_single_transfer);

void omap_set_lcd_dma_b1_rotation(int rotate)
{
    if (cpu_is_omap15xx()) {
        printk(KERN_ERR "DMA rotation is not supported in 1510 mode\n");
        BUG();
        return;
    }
    lcd_dma.rotate = rotate;
}
EXPORT_SYMBOL(omap_set_lcd_dma_b1_rotation);

void omap_set_lcd_dma_b1_mirror(int mirror)
{
    if (cpu_is_omap15xx()) {
        printk(KERN_ERR "DMA mirror is not supported in 1510 mode\n");
        BUG();
    }
    lcd_dma.mirror = mirror;
}
EXPORT_SYMBOL(omap_set_lcd_dma_b1_mirror);

void omap_set_lcd_dma_b1_vxres(unsigned long vxres)
{
    if (cpu_is_omap15xx()) {
        pr_err("DMA virtual resolution is not supported in 1510 mode\n");
        BUG();
    }
    lcd_dma.vxres = vxres;
}
EXPORT_SYMBOL(omap_set_lcd_dma_b1_vxres);

void omap_set_lcd_dma_b1_scale(unsigned int xscale, unsigned int yscale)
{
    if (cpu_is_omap15xx()) {
        printk(KERN_ERR "DMA scale is not supported in 1510 mode\n");
        BUG();
    }
    lcd_dma.xscale = xscale;
    lcd_dma.yscale = yscale;
}
EXPORT_SYMBOL(omap_set_lcd_dma_b1_scale);

static void set_b1_regs(void)
{
    unsigned long top, bottom;
    int es;
    u16 w;
    unsigned long en, fn;
    long ei, fi;
    unsigned long vxres;
    unsigned int xscale, yscale;

    switch (lcd_dma.data_type) {
    case OMAP_DMA_DATA_TYPE_S8:
        es = 1;
        break;
    case OMAP_DMA_DATA_TYPE_S16:
        es = 2;
        break;
    case OMAP_DMA_DATA_TYPE_S32:
        es = 4;
        break;
    default:
        BUG();
        return;
    }

    vxres = lcd_dma.vxres ? lcd_dma.vxres : lcd_dma.xres;
    xscale = lcd_dma.xscale ? lcd_dma.xscale : 1;
    yscale = lcd_dma.yscale ? lcd_dma.yscale : 1;
    BUG_ON(vxres < lcd_dma.xres);

#define PIXADDR(x, y) (lcd_dma.addr +                   \
        ((y) * vxres * yscale + (x) * xscale) * es)
#define PIXSTEP(sx, sy, dx, dy) (PIXADDR(dx, dy) - PIXADDR(sx, sy) - es + 1)

    switch (lcd_dma.rotate) {
    case 0:
        if (!lcd_dma.mirror) {
            top = PIXADDR(0, 0);
            bottom = PIXADDR(lcd_dma.xres - 1, lcd_dma.yres - 1);
            /* 1510 DMA requires the bottom address to be 2 more
             * than the actual last memory access location. */
            if (cpu_is_omap15xx() &&
                lcd_dma.data_type == OMAP_DMA_DATA_TYPE_S32)
                    bottom += 2;
            ei = PIXSTEP(0, 0, 1, 0);
            fi = PIXSTEP(lcd_dma.xres - 1, 0, 0, 1);
        } else {
            top = PIXADDR(lcd_dma.xres - 1, 0);
            bottom = PIXADDR(0, lcd_dma.yres - 1);
            ei = PIXSTEP(1, 0, 0, 0);
            fi = PIXSTEP(0, 0, lcd_dma.xres - 1, 1);
        }
        en = lcd_dma.xres;
        fn = lcd_dma.yres;
        break;
    case 90:
        if (!lcd_dma.mirror) {
            top = PIXADDR(0, lcd_dma.yres - 1);
            bottom = PIXADDR(lcd_dma.xres - 1, 0);
            ei = PIXSTEP(0, 1, 0, 0);
            fi = PIXSTEP(0, 0, 1, lcd_dma.yres - 1);
        } else {
            top = PIXADDR(lcd_dma.xres - 1, lcd_dma.yres - 1);
            bottom = PIXADDR(0, 0);
            ei = PIXSTEP(0, 1, 0, 0);
            fi = PIXSTEP(1, 0, 0, lcd_dma.yres - 1);
        }
        en = lcd_dma.yres;
        fn = lcd_dma.xres;
        break;
    case 180:
        if (!lcd_dma.mirror) {
            top = PIXADDR(lcd_dma.xres - 1, lcd_dma.yres - 1);
            bottom = PIXADDR(0, 0);
            ei = PIXSTEP(1, 0, 0, 0);
            fi = PIXSTEP(0, 1, lcd_dma.xres - 1, 0);
        } else {
            top = PIXADDR(0, lcd_dma.yres - 1);
            bottom = PIXADDR(lcd_dma.xres - 1, 0);
            ei = PIXSTEP(0, 0, 1, 0);
            fi = PIXSTEP(lcd_dma.xres - 1, 1, 0, 0);
        }
        en = lcd_dma.xres;
        fn = lcd_dma.yres;
        break;
    case 270:
        if (!lcd_dma.mirror) {
            top = PIXADDR(lcd_dma.xres - 1, 0);
            bottom = PIXADDR(0, lcd_dma.yres - 1);
            ei = PIXSTEP(0, 0, 0, 1);
            fi = PIXSTEP(1, lcd_dma.yres - 1, 0, 0);
        } else {
            top = PIXADDR(0, 0);
            bottom = PIXADDR(lcd_dma.xres - 1, lcd_dma.yres - 1);
            ei = PIXSTEP(0, 0, 0, 1);
            fi = PIXSTEP(0, lcd_dma.yres - 1, 1, 0);
        }
        en = lcd_dma.yres;
        fn = lcd_dma.xres;
        break;
    default:
        BUG();
        return; /* Suppress warning about uninitialized vars */
    }

    if (cpu_is_omap15xx()) {
        omap_writew(top >> 16, OMAP1510_DMA_LCD_TOP_F1_U);
        omap_writew(top, OMAP1510_DMA_LCD_TOP_F1_L);
        omap_writew(bottom >> 16, OMAP1510_DMA_LCD_BOT_F1_U);
        omap_writew(bottom, OMAP1510_DMA_LCD_BOT_F1_L);

        return;
    }

    /* 1610 regs */
    omap_writew(top >> 16, OMAP1610_DMA_LCD_TOP_B1_U);
    omap_writew(top, OMAP1610_DMA_LCD_TOP_B1_L);
    omap_writew(bottom >> 16, OMAP1610_DMA_LCD_BOT_B1_U);
    omap_writew(bottom, OMAP1610_DMA_LCD_BOT_B1_L);

    omap_writew(en, OMAP1610_DMA_LCD_SRC_EN_B1);
    omap_writew(fn, OMAP1610_DMA_LCD_SRC_FN_B1);

    w = omap_readw(OMAP1610_DMA_LCD_CSDP);
    w &= ~0x03;
    w |= lcd_dma.data_type;
    omap_writew(w, OMAP1610_DMA_LCD_CSDP);

    w = omap_readw(OMAP1610_DMA_LCD_CTRL);
    /* Always set the source port as SDRAM for now*/
    w &= ~(0x03 << 6);
    if (lcd_dma.callback != NULL)
        w |= 1 << 1;        /* Block interrupt enable */
    else
        w &= ~(1 << 1);
    omap_writew(w, OMAP1610_DMA_LCD_CTRL);

    if (!(lcd_dma.rotate || lcd_dma.mirror ||
          lcd_dma.vxres || lcd_dma.xscale || lcd_dma.yscale))
        return;

    w = omap_readw(OMAP1610_DMA_LCD_CCR);
    /* Set the double-indexed addressing mode */
    w |= (0x03 << 12);
    omap_writew(w, OMAP1610_DMA_LCD_CCR);

    omap_writew(ei, OMAP1610_DMA_LCD_SRC_EI_B1);
    omap_writew(fi >> 16, OMAP1610_DMA_LCD_SRC_FI_B1_U);
    omap_writew(fi, OMAP1610_DMA_LCD_SRC_FI_B1_L);
}

static irqreturn_t lcd_dma_irq_handler(int irq, void *dev_id)
{
    u16 w;

    w = omap_readw(OMAP1610_DMA_LCD_CTRL);
    if (unlikely(!(w & (1 << 3)))) {
        printk(KERN_WARNING "Spurious LCD DMA IRQ\n");
        return IRQ_NONE;
    }
    /* Ack the IRQ */
    w |= (1 << 3);
    omap_writew(w, OMAP1610_DMA_LCD_CTRL);
    lcd_dma.active = 0;
    if (lcd_dma.callback != NULL)
        lcd_dma.callback(w, lcd_dma.cb_data);

    return IRQ_HANDLED;
}

int omap_request_lcd_dma(void (*callback)(u16 status, void *data),
             void *data)
{
    spin_lock_irq(&lcd_dma.lock);
    if (lcd_dma.reserved) {
        spin_unlock_irq(&lcd_dma.lock);
        printk(KERN_ERR "LCD DMA channel already reserved\n");
        BUG();
        return -EBUSY;
    }
    lcd_dma.reserved = 1;
    spin_unlock_irq(&lcd_dma.lock);
    lcd_dma.callback = callback;
    lcd_dma.cb_data = data;
    lcd_dma.active = 0;
    lcd_dma.single_transfer = 0;
    lcd_dma.rotate = 0;
    lcd_dma.vxres = 0;
    lcd_dma.mirror = 0;
    lcd_dma.xscale = 0;
    lcd_dma.yscale = 0;
    lcd_dma.ext_ctrl = 0;
    lcd_dma.src_port = 0;

    return 0;
}
EXPORT_SYMBOL(omap_request_lcd_dma);

void omap_free_lcd_dma(void)
{
    spin_lock(&lcd_dma.lock);
    if (!lcd_dma.reserved) {
        spin_unlock(&lcd_dma.lock);
        printk(KERN_ERR "LCD DMA is not reserved\n");
        BUG();
        return;
    }
    if (!cpu_is_omap15xx())
        omap_writew(omap_readw(OMAP1610_DMA_LCD_CCR) & ~1,
                OMAP1610_DMA_LCD_CCR);
    lcd_dma.reserved = 0;
    spin_unlock(&lcd_dma.lock);
}
EXPORT_SYMBOL(omap_free_lcd_dma);

void omap_enable_lcd_dma(void)
{
    u16 w;

    /*
     * Set the Enable bit only if an external controller is
     * connected. Otherwise the OMAP internal controller will
     * start the transfer when it gets enabled.
     */
    if (cpu_is_omap15xx() || !lcd_dma.ext_ctrl)
        return;

    w = omap_readw(OMAP1610_DMA_LCD_CTRL);
    w |= 1 << 8;
    omap_writew(w, OMAP1610_DMA_LCD_CTRL);

    lcd_dma.active = 1;

    w = omap_readw(OMAP1610_DMA_LCD_CCR);
    w |= 1 << 7;
    omap_writew(w, OMAP1610_DMA_LCD_CCR);
}
EXPORT_SYMBOL(omap_enable_lcd_dma);

void omap_setup_lcd_dma(void)
{
    BUG_ON(lcd_dma.active);
    if (!cpu_is_omap15xx()) {
        /* Set some reasonable defaults */
        omap_writew(0x5440, OMAP1610_DMA_LCD_CCR);
        omap_writew(0x9102, OMAP1610_DMA_LCD_CSDP);
        omap_writew(0x0004, OMAP1610_DMA_LCD_LCH_CTRL);
    }
    set_b1_regs();
    if (!cpu_is_omap15xx()) {
        u16 w;

        w = omap_readw(OMAP1610_DMA_LCD_CCR);
        /*
         * If DMA was already active set the end_prog bit to have
         * the programmed register set loaded into the active
         * register set.
         */
        w |= 1 << 11;       /* End_prog */
        if (!lcd_dma.single_transfer)
            w |= (3 << 8);  /* Auto_init, repeat */
        omap_writew(w, OMAP1610_DMA_LCD_CCR);
    }
}
EXPORT_SYMBOL(omap_setup_lcd_dma);

void omap_stop_lcd_dma(void)
{
    u16 w;

    lcd_dma.active = 0;
    if (cpu_is_omap15xx() || !lcd_dma.ext_ctrl)
        return;

    w = omap_readw(OMAP1610_DMA_LCD_CCR);
    w &= ~(1 << 7);
    omap_writew(w, OMAP1610_DMA_LCD_CCR);

    w = omap_readw(OMAP1610_DMA_LCD_CTRL);
    w &= ~(1 << 8);
    omap_writew(w, OMAP1610_DMA_LCD_CTRL);
}
EXPORT_SYMBOL(omap_stop_lcd_dma);

static int __init omap_init_lcd_dma(void)
{
    int r;

    if (!cpu_class_is_omap1())
        return -ENODEV;

    if (cpu_is_omap16xx()) {
        u16 w;

        /* this would prevent OMAP sleep */
        w = omap_readw(OMAP1610_DMA_LCD_CTRL);
        w &= ~(1 << 8);
        omap_writew(w, OMAP1610_DMA_LCD_CTRL);
    }

    spin_lock_init(&lcd_dma.lock);

    r = request_irq(INT_DMA_LCD, lcd_dma_irq_handler, 0,
            "LCD DMA", NULL);
    if (r != 0)
        pr_err("unable to request IRQ for LCD DMA (error %d)\n", r);

    return r;
}

arch_initcall(omap_init_lcd_dma);