sh_mobile_lcdcfb.c

Linux环境下视频显示卡设备的驱动程序源代码

/*
 * SuperH Mobile LCDC Framebuffer
 *
 * Copyright (c) 2008 Magnus Damm
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/mm.h>
#include <linux/fb.h>
#include <linux/clk.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <video/sh_mobile_lcdc.h>
#include <asm/atomic.h>

#define PALETTE_NR 16

struct sh_mobile_lcdc_priv;
struct sh_mobile_lcdc_chan {
	struct sh_mobile_lcdc_priv *lcdc;
	unsigned long *reg_offs;
	unsigned long ldmt1r_value;
	unsigned long enabled; /* ME and SE in LDCNT2R */
	struct sh_mobile_lcdc_chan_cfg cfg;
	u32 pseudo_palette[PALETTE_NR];
	struct fb_info info;
	dma_addr_t dma_handle;
	struct fb_deferred_io defio;
};

struct sh_mobile_lcdc_priv {
	void __iomem *base;
	int irq;
#ifdef CONFIG_HAVE_CLK
	atomic_t clk_usecnt;
	struct clk *dot_clk;
	struct clk *clk;
#endif
	unsigned long lddckr;
	struct sh_mobile_lcdc_chan ch[2];
};

/* shared registers */
#define _LDDCKR 0x410
#define _LDDCKSTPR 0x414
#define _LDINTR 0x468
#define _LDSR 0x46c
#define _LDCNT1R 0x470
#define _LDCNT2R 0x474
#define _LDDDSR 0x47c
#define _LDDWD0R 0x800
#define _LDDRDR 0x840
#define _LDDWAR 0x900
#define _LDDRAR 0x904

/* per-channel registers */
enum { LDDCKPAT1R, LDDCKPAT2R, LDMT1R, LDMT2R, LDMT3R, LDDFR, LDSM1R,
       LDSM2R, LDSA1R, LDMLSR, LDHCNR, LDHSYNR, LDVLNR, LDVSYNR, LDPMR };

static unsigned long lcdc_offs_mainlcd[] = {
	[LDDCKPAT1R] = 0x400,
	[LDDCKPAT2R] = 0x404,
	[LDMT1R] = 0x418,
	[LDMT2R] = 0x41c,
	[LDMT3R] = 0x420,
	[LDDFR] = 0x424,
	[LDSM1R] = 0x428,
	[LDSM2R] = 0x42c,
	[LDSA1R] = 0x430,
	[LDMLSR] = 0x438,
	[LDHCNR] = 0x448,
	[LDHSYNR] = 0x44c,
	[LDVLNR] = 0x450,
	[LDVSYNR] = 0x454,
	[LDPMR] = 0x460,
};

static unsigned long lcdc_offs_sublcd[] = {
	[LDDCKPAT1R] = 0x408,
	[LDDCKPAT2R] = 0x40c,
	[LDMT1R] = 0x600,
	[LDMT2R] = 0x604,
	[LDMT3R] = 0x608,
	[LDDFR] = 0x60c,
	[LDSM1R] = 0x610,
	[LDSM2R] = 0x614,
	[LDSA1R] = 0x618,
	[LDMLSR] = 0x620,
	[LDHCNR] = 0x624,
	[LDHSYNR] = 0x628,
	[LDVLNR] = 0x62c,
	[LDVSYNR] = 0x630,
	[LDPMR] = 0x63c,
};

#define START_LCDC	0x00000001
#define LCDC_RESET	0x00000100
#define DISPLAY_BEU	0x00000008
#define LCDC_ENABLE	0x00000001
#define LDINTR_FE	0x00000400
#define LDINTR_FS	0x00000004

static void lcdc_write_chan(struct sh_mobile_lcdc_chan *chan,
			    int reg_nr, unsigned long data)
{
	iowrite32(data, chan->lcdc->base + chan->reg_offs[reg_nr]);
}

static unsigned long lcdc_read_chan(struct sh_mobile_lcdc_chan *chan,
				    int reg_nr)
{
	return ioread32(chan->lcdc->base + chan->reg_offs[reg_nr]);
}

static void lcdc_write(struct sh_mobile_lcdc_priv *priv,
		       unsigned long reg_offs, unsigned long data)
{
	iowrite32(data, priv->base + reg_offs);
}

static unsigned long lcdc_read(struct sh_mobile_lcdc_priv *priv,
			       unsigned long reg_offs)
{
	return ioread32(priv->base + reg_offs);
}

static void lcdc_wait_bit(struct sh_mobile_lcdc_priv *priv,
			  unsigned long reg_offs,
			  unsigned long mask, unsigned long until)
{
	while ((lcdc_read(priv, reg_offs) & mask) != until)
		cpu_relax();
}

static int lcdc_chan_is_sublcd(struct sh_mobile_lcdc_chan *chan)
{
	return chan->cfg.chan == LCDC_CHAN_SUBLCD;
}

static void lcdc_sys_write_index(void *handle, unsigned long data)
{
	struct sh_mobile_lcdc_chan *ch = handle;

	lcdc_write(ch->lcdc, _LDDWD0R, data | 0x10000000);
	lcdc_wait_bit(ch->lcdc, _LDSR, 2, 0);
	lcdc_write(ch->lcdc, _LDDWAR, 1 | (lcdc_chan_is_sublcd(ch) ? 2 : 0));
}

static void lcdc_sys_write_data(void *handle, unsigned long data)
{
	struct sh_mobile_lcdc_chan *ch = handle;

	lcdc_write(ch->lcdc, _LDDWD0R, data | 0x11000000);
	lcdc_wait_bit(ch->lcdc, _LDSR, 2, 0);
	lcdc_write(ch->lcdc, _LDDWAR, 1 | (lcdc_chan_is_sublcd(ch) ? 2 : 0));
}

static unsigned long lcdc_sys_read_data(void *handle)
{
	struct sh_mobile_lcdc_chan *ch = handle;

	lcdc_write(ch->lcdc, _LDDRDR, 0x01000000);
	lcdc_wait_bit(ch->lcdc, _LDSR, 2, 0);
	lcdc_write(ch->lcdc, _LDDRAR, 1 | (lcdc_chan_is_sublcd(ch) ? 2 : 0));
	udelay(1);

	return lcdc_read(ch->lcdc, _LDDRDR) & 0xffff;
}

struct sh_mobile_lcdc_sys_bus_ops sh_mobile_lcdc_sys_bus_ops = {
	lcdc_sys_write_index,
	lcdc_sys_write_data,
	lcdc_sys_read_data,
};

#ifdef CONFIG_HAVE_CLK
static void sh_mobile_lcdc_clk_on(struct sh_mobile_lcdc_priv *priv)
{
	if (atomic_inc_and_test(&priv->clk_usecnt)) {
		clk_enable(priv->clk);
		if (priv->dot_clk)
			clk_enable(priv->dot_clk);
	}
}

static void sh_mobile_lcdc_clk_off(struct sh_mobile_lcdc_priv *priv)
{
	if (atomic_sub_return(1, &priv->clk_usecnt) == -1) {
		if (priv->dot_clk)
			clk_disable(priv->dot_clk);
		clk_disable(priv->clk);
	}
}
#else
static void sh_mobile_lcdc_clk_on(struct sh_mobile_lcdc_priv *priv) {}
static void sh_mobile_lcdc_clk_off(struct sh_mobile_lcdc_priv *priv) {}
#endif

static void sh_mobile_lcdc_deferred_io(struct fb_info *info,
				       struct list_head *pagelist)
{
	struct sh_mobile_lcdc_chan *ch = info->par;

	/* enable clocks before accessing hardware */
	sh_mobile_lcdc_clk_on(ch->lcdc);

	/* trigger panel update */
	lcdc_write_chan(ch, LDSM2R, 1);
}

static void sh_mobile_lcdc_deferred_io_touch(struct fb_info *info)
{
	struct fb_deferred_io *fbdefio = info->fbdefio;

	if (fbdefio)
		schedule_delayed_work(&info->deferred_work, fbdefio->delay);
}

static irqreturn_t sh_mobile_lcdc_irq(int irq, void *data)
{
	struct sh_mobile_lcdc_priv *priv = data;
	unsigned long tmp;

	/* acknowledge interrupt */
	tmp = lcdc_read(priv, _LDINTR);
	tmp &= 0xffffff00; /* mask in high 24 bits */
	tmp |= 0x000000ff ^ LDINTR_FS; /* status in low 8 */
	lcdc_write(priv, _LDINTR, tmp);

	/* disable clocks */
	sh_mobile_lcdc_clk_off(priv);
	return IRQ_HANDLED;
}

static void sh_mobile_lcdc_start_stop(struct sh_mobile_lcdc_priv *priv,
				      int start)
{
	unsigned long tmp = lcdc_read(priv, _LDCNT2R);
	int k;

	/* start or stop the lcdc */
	if (start)
		lcdc_write(priv, _LDCNT2R, tmp | START_LCDC);
	else
		lcdc_write(priv, _LDCNT2R, tmp & ~START_LCDC);

	/* wait until power is applied/stopped on all channels */
	for (k = 0; k < ARRAY_SIZE(priv->ch); k++)
		if (lcdc_read(priv, _LDCNT2R) & priv->ch[k].enabled)
			while (1) {
				tmp = lcdc_read_chan(&priv->ch[k], LDPMR) & 3;
				if (start && tmp == 3)
					break;
				if (!start && tmp == 0)
					break;
				cpu_relax();
			}

	if (!start)
		lcdc_write(priv, _LDDCKSTPR, 1); /* stop dotclock */
}

static int sh_mobile_lcdc_start(struct sh_mobile_lcdc_priv *priv)
{
	struct sh_mobile_lcdc_chan *ch;
	struct fb_videomode *lcd_cfg;
	struct sh_mobile_lcdc_board_cfg	*board_cfg;
	unsigned long tmp;
	int k, m;
	int ret = 0;

	/* enable clocks before accessing the hardware */
	for (k = 0; k < ARRAY_SIZE(priv->ch); k++)
		if (priv->ch[k].enabled)
			sh_mobile_lcdc_clk_on(priv);

	/* reset */
	lcdc_write(priv, _LDCNT2R, lcdc_read(priv, _LDCNT2R) | LCDC_RESET);
	lcdc_wait_bit(priv, _LDCNT2R, LCDC_RESET, 0);

	/* enable LCDC channels */
	tmp = lcdc_read(priv, _LDCNT2R);
	tmp |= priv->ch[0].enabled;
	tmp |= priv->ch[1].enabled;
	lcdc_write(priv, _LDCNT2R, tmp);

	/* read data from external memory, avoid using the BEU for now */
	lcdc_write(priv, _LDCNT2R, lcdc_read(priv, _LDCNT2R) & ~DISPLAY_BEU);

	/* stop the lcdc first */
	sh_mobile_lcdc_start_stop(priv, 0);

	/* configure clocks */
	tmp = priv->lddckr;
	for (k = 0; k < ARRAY_SIZE(priv->ch); k++) {
		ch = &priv->ch[k];

		if (!priv->ch[k].enabled)
			continue;

		m = ch->cfg.clock_divider;
		if (!m)
			continue;

		if (m == 1)
			m = 1 << 6;
		tmp |= m << (lcdc_chan_is_sublcd(ch) ? 8 : 0);

		lcdc_write_chan(ch, LDDCKPAT1R, 0x00000000);
		lcdc_write_chan(ch, LDDCKPAT2R, (1 << (m/2)) - 1);
	}

	lcdc_write(priv, _LDDCKR, tmp);

	/* start dotclock again */
	lcdc_write(priv, _LDDCKSTPR, 0);
	lcdc_wait_bit(priv, _LDDCKSTPR, ~0, 0);

	/* interrupts are disabled to begin with */
	lcdc_write(priv, _LDINTR, 0);

	for (k = 0; k < ARRAY_SIZE(priv->ch); k++) {
		ch = &priv->ch[k];
		lcd_cfg = &ch->cfg.lcd_cfg;

		if (!ch->enabled)
			continue;

		tmp = ch->ldmt1r_value;
		tmp |= (lcd_cfg->sync & FB_SYNC_VERT_HIGH_ACT) ? 0 : 1 << 28;
		tmp |= (lcd_cfg->sync & FB_SYNC_HOR_HIGH_ACT) ? 0 : 1 << 27;
		tmp |= (ch->cfg.flags & LCDC_FLAGS_DWPOL) ? 1 << 26 : 0;
		tmp |= (ch->cfg.flags & LCDC_FLAGS_DIPOL) ? 1 << 25 : 0;
		tmp |= (ch->cfg.flags & LCDC_FLAGS_DAPOL) ? 1 << 24 : 0;
		tmp |= (ch->cfg.flags & LCDC_FLAGS_HSCNT) ? 1 << 17 : 0;
		tmp |= (ch->cfg.flags & LCDC_FLAGS_DWCNT) ? 1 << 16 : 0;
		lcdc_write_chan(ch, LDMT1R, tmp);

		/* setup SYS bus */
		lcdc_write_chan(ch, LDMT2R, ch->cfg.sys_bus_cfg.ldmt2r);
		lcdc_write_chan(ch, LDMT3R, ch->cfg.sys_bus_cfg.ldmt3r);

		/* horizontal configuration */
		tmp = lcd_cfg->xres + lcd_cfg->hsync_len;
		tmp += lcd_cfg->left_margin;
		tmp += lcd_cfg->right_margin;
		tmp /= 8; /* HTCN */
		tmp |= (lcd_cfg->xres / 8) << 16; /* HDCN */
		lcdc_write_chan(ch, LDHCNR, tmp);

		tmp = lcd_cfg->xres;
		tmp += lcd_cfg->right_margin;
		tmp /= 8; /* HSYNP */
		tmp |= (lcd_cfg->hsync_len / 8) << 16; /* HSYNW */
		lcdc_write_chan(ch, LDHSYNR, tmp);

		/* power supply */
		lcdc_write_chan(ch, LDPMR, 0);

		/* vertical configuration */
		tmp = lcd_cfg->yres + lcd_cfg->vsync_len;
		tmp += lcd_cfg->upper_margin;
		tmp += lcd_cfg->lower_margin; /* VTLN */
		tmp |= lcd_cfg->yres << 16; /* VDLN */
		lcdc_write_chan(ch, LDVLNR, tmp);

		tmp = lcd_cfg->yres;
		tmp += lcd_cfg->lower_margin; /* VSYNP */
		tmp |= lcd_cfg->vsync_len << 16; /* VSYNW */
		lcdc_write_chan(ch, LDVSYNR, tmp);

		board_cfg = &ch->cfg.board_cfg;
		if (board_cfg->setup_sys)
			ret = board_cfg->setup_sys(board_cfg->board_data, ch,
						   &sh_mobile_lcdc_sys_bus_ops);
		if (ret)
			return ret;
	}

	/* word and long word swap */
	lcdc_write(priv, _LDDDSR, lcdc_read(priv, _LDDDSR) | 6);

	for (k = 0; k < ARRAY_SIZE(priv->ch); k++) {
		ch = &priv->ch[k];

		if (!priv->ch[k].enabled)
			continue;

		/* set bpp format in PKF[4:0] */
		tmp = lcdc_read_chan(ch, LDDFR);
		tmp &= ~(0x0001001f);
		tmp |= (priv->ch[k].info.var.bits_per_pixel == 16) ? 3 : 0;
		lcdc_write_chan(ch, LDDFR, tmp);

		/* point out our frame buffer */
		lcdc_write_chan(ch, LDSA1R, ch->info.fix.smem_start);

		/* set line size */
		lcdc_write_chan(ch, LDMLSR, ch->info.fix.line_length);

		/* setup deferred io if SYS bus */
		tmp = ch->cfg.sys_bus_cfg.deferred_io_msec;
		if (ch->ldmt1r_value & (1 << 12) && tmp) {
			ch->defio.deferred_io = sh_mobile_lcdc_deferred_io;
			ch->defio.delay = msecs_to_jiffies(tmp);
			ch->info.fbdefio = &ch->defio;
			fb_deferred_io_init(&ch->info);

			/* one-shot mode */
			lcdc_write_chan(ch, LDSM1R, 1);

			/* enable "Frame End Interrupt Enable" bit */
			lcdc_write(priv, _LDINTR, LDINTR_FE);

		} else {
			/* continuous read mode */
			lcdc_write_chan(ch, LDSM1R, 0);
		}
	}

	/* display output */
	lcdc_write(priv, _LDCNT1R, LCDC_ENABLE);

	/* start the lcdc */
	sh_mobile_lcdc_start_stop(priv, 1);

	/* tell the board code to enable the panel */
	for (k = 0; k < ARRAY_SIZE(priv->ch); k++) {
		ch = &priv->ch[k];
		board_cfg = &ch->cfg.board_cfg;
		if (board_cfg->display_on)
			board_cfg->display_on(board_cfg->board_data);
	}

	return 0;