OMAP: add TI OMAP2 external LCD controller support - RFBI

- Adds support for Texas Instruments OMAP2 processors boards connected with
  external LCD controller through "Remote framebuffer Interface"
Signed-off-by: Trilok Soni <soni.trilok@gmail.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/omap/Makefile

@@ -10,6 +10,7 @@ objs-y$(CONFIG_ARCH_OMAP1) += lcdc.o
 objs-y$(CONFIG_ARCH_OMAP2) += dispc.o
 
 objs-$(CONFIG_ARCH_OMAP1)$(CONFIG_FB_OMAP_LCDC_EXTERNAL) += sossi.o
+objs-$(CONFIG_ARCH_OMAP2)$(CONFIG_FB_OMAP_LCDC_EXTERNAL) += rfbi.o
 
 omapfb-objs := $(objs-yy)
 

drivers/video/omap/rfbi.c

+/*
+ * OMAP2 Remote Frame Buffer Interface support
+ *
+ * Copyright (C) 2005 Nokia Corporation
+ * Author: Juha Yrjl <juha.yrjola@nokia.com>
+ *	   Imre Deak <imre.deak@nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+
+#include <asm/arch/omapfb.h>
+
+#include "dispc.h"
+
+/* To work around an RFBI transfer rate limitation */
+#define OMAP_RFBI_RATE_LIMIT	1
+
+#define RFBI_BASE		0x48050800
+#define RFBI_REVISION		0x0000
+#define RFBI_SYSCONFIG		0x0010
+#define RFBI_SYSSTATUS		0x0014
+#define RFBI_CONTROL		0x0040
+#define RFBI_PIXEL_CNT		0x0044
+#define RFBI_LINE_NUMBER	0x0048
+#define RFBI_CMD		0x004c
+#define RFBI_PARAM		0x0050
+#define RFBI_DATA		0x0054
+#define RFBI_READ		0x0058
+#define RFBI_STATUS		0x005c
+#define RFBI_CONFIG0		0x0060
+#define RFBI_ONOFF_TIME0	0x0064
+#define RFBI_CYCLE_TIME0	0x0068
+#define RFBI_DATA_CYCLE1_0	0x006c
+#define RFBI_DATA_CYCLE2_0	0x0070
+#define RFBI_DATA_CYCLE3_0	0x0074
+#define RFBI_VSYNC_WIDTH	0x0090
+#define RFBI_HSYNC_WIDTH	0x0094
+
+#define DISPC_BASE		0x48050400
+#define DISPC_CONTROL		0x0040
+
+static struct {
+	u32		base;
+	void		(*lcdc_callback)(void *data);
+	void		*lcdc_callback_data;
+	unsigned long	l4_khz;
+	int		bits_per_cycle;
+	struct omapfb_device *fbdev;
+	struct clk	*dss_ick;
+	struct clk	*dss1_fck;
+	unsigned	tearsync_pin_cnt;
+	unsigned	tearsync_mode;
+} rfbi;
+
+static inline void rfbi_write_reg(int idx, u32 val)
+{
+	__raw_writel(val, rfbi.base + idx);
+}
+
+static inline u32 rfbi_read_reg(int idx)
+{
+	return __raw_readl(rfbi.base + idx);
+}
+
+static int rfbi_get_clocks(void)
+{
+	if (IS_ERR((rfbi.dss_ick = clk_get(rfbi.fbdev->dev, "dss_ick")))) {
+		dev_err(rfbi.fbdev->dev, "can't get dss_ick");
+		return PTR_ERR(rfbi.dss_ick);
+	}
+
+	if (IS_ERR((rfbi.dss1_fck = clk_get(rfbi.fbdev->dev, "dss1_fck")))) {
+		dev_err(rfbi.fbdev->dev, "can't get dss1_fck");
+		clk_put(rfbi.dss_ick);
+		return PTR_ERR(rfbi.dss1_fck);
+	}
+
+	return 0;
+}
+
+static void rfbi_put_clocks(void)
+{
+	clk_put(rfbi.dss1_fck);
+	clk_put(rfbi.dss_ick);
+}
+
+static void rfbi_enable_clocks(int enable)
+{
+	if (enable) {
+		clk_enable(rfbi.dss_ick);
+		clk_enable(rfbi.dss1_fck);
+	} else {
+		clk_disable(rfbi.dss1_fck);
+		clk_disable(rfbi.dss_ick);
+	}
+}
+
+
+#ifdef VERBOSE
+static void rfbi_print_timings(void)
+{
+	u32 l;
+	u32 time;
+
+	l = rfbi_read_reg(RFBI_CONFIG0);
+	time = 1000000000 / rfbi.l4_khz;
+	if (l & (1 << 4))
+		time *= 2;
+
+	dev_dbg(rfbi.fbdev->dev, "Tick time %u ps\n", time);
+	l = rfbi_read_reg(RFBI_ONOFF_TIME0);
+	dev_dbg(rfbi.fbdev->dev,
+		"CSONTIME %d, CSOFFTIME %d, WEONTIME %d, WEOFFTIME %d, "
+		"REONTIME %d, REOFFTIME %d\n",
+		l & 0x0f, (l >> 4) & 0x3f, (l >> 10) & 0x0f, (l >> 14) & 0x3f,
+		(l >> 20) & 0x0f, (l >> 24) & 0x3f);
+
+	l = rfbi_read_reg(RFBI_CYCLE_TIME0);
+	dev_dbg(rfbi.fbdev->dev,
+		"WECYCLETIME %d, RECYCLETIME %d, CSPULSEWIDTH %d, "
+		"ACCESSTIME %d\n",
+		(l & 0x3f), (l >> 6) & 0x3f, (l >> 12) & 0x3f,
+		(l >> 22) & 0x3f);
+}
+#else
+static void rfbi_print_timings(void) {}
+#endif
+
+static void rfbi_set_timings(const struct extif_timings *t)
+{
+	u32 l;
+
+	BUG_ON(!t->converted);
+
+	rfbi_enable_clocks(1);
+	rfbi_write_reg(RFBI_ONOFF_TIME0, t->tim[0]);
+	rfbi_write_reg(RFBI_CYCLE_TIME0, t->tim[1]);
+
+	l = rfbi_read_reg(RFBI_CONFIG0);
+	l &= ~(1 << 4);
+	l |= (t->tim[2] ? 1 : 0) << 4;
+	rfbi_write_reg(RFBI_CONFIG0, l);
+
+	rfbi_print_timings();
+	rfbi_enable_clocks(0);
+}
+
+static void rfbi_get_clk_info(u32 *clk_period, u32 *max_clk_div)
+{
+	*clk_period = 1000000000 / rfbi.l4_khz;
+	*max_clk_div = 2;
+}
+
+static int ps_to_rfbi_ticks(int time, int div)
+{
+	unsigned long tick_ps;
+	int ret;
+
+	/* Calculate in picosecs to yield more exact results */
+	tick_ps = 1000000000 / (rfbi.l4_khz) * div;
+
+	ret = (time + tick_ps - 1) / tick_ps;
+
+	return ret;
+}
+
+#ifdef OMAP_RFBI_RATE_LIMIT
+static unsigned long rfbi_get_max_tx_rate(void)
+{
+	unsigned long	l4_rate, dss1_rate;
+	int		min_l4_ticks = 0;
+	int		i;
+
+	/* According to TI this can't be calculated so make the
+	 * adjustments for a couple of known frequencies and warn for
+	 * others.
+	 */
+	static const struct {
+		unsigned long l4_clk;		/* HZ */
+		unsigned long dss1_clk;		/* HZ */
+		unsigned long min_l4_ticks;
+	} ftab[] = {
+		{ 55,	132,	7, },		/* 7.86 MPix/s */
+		{ 110,	110,	12, },		/* 9.16 MPix/s */
+		{ 110,	132,	10, },		/* 11   Mpix/s */
+		{ 120,	120,	10, },		/* 12   Mpix/s */
+		{ 133,	133,	10, },		/* 13.3 Mpix/s */
+	};
+
+	l4_rate = rfbi.l4_khz / 1000;
+	dss1_rate = clk_get_rate(rfbi.dss1_fck) / 1000000;
+
+	for (i = 0; i < ARRAY_SIZE(ftab); i++) {
+		/* Use a window instead of an exact match, to account
+		 * for different DPLL multiplier / divider pairs.
+		 */
+		if (abs(ftab[i].l4_clk - l4_rate) < 3 &&
+		    abs(ftab[i].dss1_clk - dss1_rate) < 3) {
+			min_l4_ticks = ftab[i].min_l4_ticks;
+			break;
+		}
+	}
+	if (i == ARRAY_SIZE(ftab)) {
+		/* Can't be sure, return anyway the maximum not
+		 * rate-limited. This might cause a problem only for the
+		 * tearing synchronisation.
+		 */
+		dev_err(rfbi.fbdev->dev,
+			"can't determine maximum RFBI transfer rate\n");
+		return rfbi.l4_khz * 1000;
+	}
+	return rfbi.l4_khz * 1000 / min_l4_ticks;
+}
+#else
+static int rfbi_get_max_tx_rate(void)
+{
+	return rfbi.l4_khz * 1000;
+}
+#endif
+
+
+static int rfbi_convert_timings(struct extif_timings *t)
+{
+	u32 l;
+	int reon, reoff, weon, weoff, cson, csoff, cs_pulse;
+	int actim, recyc, wecyc;
+	int div = t->clk_div;
+
+	if (div <= 0 || div > 2)
+		return -1;
+
+	/* Make sure that after conversion it still holds that:
+	 * weoff > weon, reoff > reon, recyc >= reoff, wecyc >= weoff,
+	 * csoff > cson, csoff >= max(weoff, reoff), actim > reon
+	 */
+	weon = ps_to_rfbi_ticks(t->we_on_time, div);
+	weoff = ps_to_rfbi_ticks(t->we_off_time, div);
+	if (weoff <= weon)
+		weoff = weon + 1;
+	if (weon > 0x0f)
+		return -1;
+	if (weoff > 0x3f)
+		return -1;
+
+	reon = ps_to_rfbi_ticks(t->re_on_time, div);
+	reoff = ps_to_rfbi_ticks(t->re_off_time, div);
+	if (reoff <= reon)
+		reoff = reon + 1;
+	if (reon > 0x0f)
+		return -1;
+	if (reoff > 0x3f)
+		return -1;
+
+	cson = ps_to_rfbi_ticks(t->cs_on_time, div);
+	csoff = ps_to_rfbi_ticks(t->cs_off_time, div);
+	if (csoff <= cson)
+		csoff = cson + 1;
+	if (csoff < max(weoff, reoff))
+		csoff = max(weoff, reoff);
+	if (cson > 0x0f)
+		return -1;
+	if (csoff > 0x3f)
+		return -1;
+
+	l =  cson;
+	l |= csoff << 4;
+	l |= weon  << 10;
+	l |= weoff << 14;
+	l |= reon  << 20;
+	l |= reoff << 24;
+
+	t->tim[0] = l;
+
+	actim = ps_to_rfbi_ticks(t->access_time, div);
+	if (actim <= reon)
+		actim = reon + 1;
+	if (actim > 0x3f)
+		return -1;
+
+	wecyc = ps_to_rfbi_ticks(t->we_cycle_time, div);
+	if (wecyc < weoff)
+		wecyc = weoff;
+	if (wecyc > 0x3f)
+		return -1;
+
+	recyc = ps_to_rfbi_ticks(t->re_cycle_time, div);
+	if (recyc < reoff)
+		recyc = reoff;
+	if (recyc > 0x3f)
+		return -1;
+
+	cs_pulse = ps_to_rfbi_ticks(t->cs_pulse_width, div);
+	if (cs_pulse > 0x3f)
+		return -1;
+
+	l =  wecyc;
+	l |= recyc    << 6;
+	l |= cs_pulse << 12;
+	l |= actim    << 22;
+
+	t->tim[1] = l;
+
+	t->tim[2] = div - 1;
+
+	t->converted = 1;
+
+	return 0;
+}
+
+static int rfbi_setup_tearsync(unsigned pin_cnt,
+			       unsigned hs_pulse_time, unsigned vs_pulse_time,
+			       int hs_pol_inv, int vs_pol_inv, int extif_div)
+{
+	int hs, vs;
+	int min;
+	u32 l;
+
+	if (pin_cnt != 1 && pin_cnt != 2)
+		return -EINVAL;
+
+	hs = ps_to_rfbi_ticks(hs_pulse_time, 1);
+	vs = ps_to_rfbi_ticks(vs_pulse_time, 1);
+	if (hs < 2)
+		return -EDOM;
+	if (pin_cnt == 2)
+		min = 2;
+	else
+		min = 4;
+	if (vs < min)
+		return -EDOM;
+	if (vs == hs)
+		return -EINVAL;
+	rfbi.tearsync_pin_cnt = pin_cnt;
+	dev_dbg(rfbi.fbdev->dev,
+		"setup_tearsync: pins %d hs %d vs %d hs_inv %d vs_inv %d\n",
+		pin_cnt, hs, vs, hs_pol_inv, vs_pol_inv);
+
+	rfbi_enable_clocks(1);
+	rfbi_write_reg(RFBI_HSYNC_WIDTH, hs);
+	rfbi_write_reg(RFBI_VSYNC_WIDTH, vs);
+
+	l = rfbi_read_reg(RFBI_CONFIG0);
+	if (hs_pol_inv)
+		l &= ~(1 << 21);
+	else
+		l |= 1 << 21;
+	if (vs_pol_inv)
+		l &= ~(1 << 20);
+	else
+		l |= 1 << 20;
+	rfbi_enable_clocks(0);
+
+	return 0;
+}
+
+static int rfbi_enable_tearsync(int enable, unsigned line)
+{
+	u32 l;
+
+	dev_dbg(rfbi.fbdev->dev, "tearsync %d line %d mode %d\n",
+		enable, line, rfbi.tearsync_mode);
+	if (line > (1 << 11) - 1)
+		return -EINVAL;
+
+	rfbi_enable_clocks(1);
+	l = rfbi_read_reg(RFBI_CONFIG0);
+	l &= ~(0x3 << 2);
+	if (enable) {
+		rfbi.tearsync_mode = rfbi.tearsync_pin_cnt;
+		l |= rfbi.tearsync_mode << 2;
+	} else
+		rfbi.tearsync_mode = 0;
+	rfbi_write_reg(RFBI_CONFIG0, l);
+	rfbi_write_reg(RFBI_LINE_NUMBER, line);
+	rfbi_enable_clocks(0);
+
+	return 0;
+}
+
+static void rfbi_write_command(const void *buf, unsigned int len)
+{
+	rfbi_enable_clocks(1);
+	if (rfbi.bits_per_cycle == 16) {
+		const u16 *w = buf;
+		BUG_ON(len & 1);
+		for (; len; len -= 2)
+			rfbi_write_reg(RFBI_CMD, *w++);
+	} else {
+		const u8 *b = buf;
+		BUG_ON(rfbi.bits_per_cycle != 8);
+		for (; len; len--)
+			rfbi_write_reg(RFBI_CMD, *b++);
+	}
+	rfbi_enable_clocks(0);
+}
+
+static void rfbi_read_data(void *buf, unsigned int len)
+{
+	rfbi_enable_clocks(1);
+	if (rfbi.bits_per_cycle == 16) {
+		u16 *w = buf;
+		BUG_ON(len & ~1);
+		for (; len; len -= 2) {
+			rfbi_write_reg(RFBI_READ, 0);
+			*w++ = rfbi_read_reg(RFBI_READ);
+		}
+	} else {
+		u8 *b = buf;
+		BUG_ON(rfbi.bits_per_cycle != 8);
+		for (; len; len--) {
+			rfbi_write_reg(RFBI_READ, 0);
+			*b++ = rfbi_read_reg(RFBI_READ);
+		}
+	}
+	rfbi_enable_clocks(0);
+}
+
+static void rfbi_write_data(const void *buf, unsigned int len)
+{
+	rfbi_enable_clocks(1);
+	if (rfbi.bits_per_cycle == 16) {
+		const u16 *w = buf;
+		BUG_ON(len & 1);
+		for (; len; len -= 2)
+			rfbi_write_reg(RFBI_PARAM, *w++);
+	} else {
+		const u8 *b = buf;
+		BUG_ON(rfbi.bits_per_cycle != 8);
+		for (; len; len--)
+			rfbi_write_reg(RFBI_PARAM, *b++);
+	}
+	rfbi_enable_clocks(0);
+}
+
+static void rfbi_transfer_area(int width, int height,
+				void (callback)(void * data), void *data)
+{
+	u32 w;
+
+	BUG_ON(callback == NULL);
+
+	rfbi_enable_clocks(1);
+	omap_dispc_set_lcd_size(width, height);
+
+	rfbi.lcdc_callback = callback;
+	rfbi.lcdc_callback_data = data;
+
+	rfbi_write_reg(RFBI_PIXEL_CNT, width * height);
+
+	w = rfbi_read_reg(RFBI_CONTROL);
+	w |= 1;				/* enable */
+	if (!rfbi.tearsync_mode)
+		w |= 1 << 4;		/* internal trigger, reset by HW */
+	rfbi_write_reg(RFBI_CONTROL, w);
+
+	omap_dispc_enable_lcd_out(1);
+}
+
+static inline void _stop_transfer(void)
+{
+	u32 w;
+
+	w = rfbi_read_reg(RFBI_CONTROL);
+	rfbi_write_reg(RFBI_CONTROL, w & ~(1 << 0));
+	rfbi_enable_clocks(0);
+}
+
+static void rfbi_dma_callback(void *data)
+{
+	_stop_transfer();
+	rfbi.lcdc_callback(rfbi.lcdc_callback_data);
+}
+
+static void rfbi_set_bits_per_cycle(int bpc)
+{
+	u32 l;
+
+	rfbi_enable_clocks(1);
+	l = rfbi_read_reg(RFBI_CONFIG0);
+	l &= ~(0x03 << 0);
+
+	switch (bpc) {
+	case 8:
+		break;
+	case 16:
+		l |= 3;
+		break;
+	default:
+		BUG();
+	}
+	rfbi_write_reg(RFBI_CONFIG0, l);
+	rfbi.bits_per_cycle = bpc;
+	rfbi_enable_clocks(0);
+}
+
+static int rfbi_init(struct omapfb_device *fbdev)
+{
+	u32 l;
+	int r;
+
+	rfbi.fbdev = fbdev;
+	rfbi.base = io_p2v(RFBI_BASE);
+
+	if ((r = rfbi_get_clocks()) < 0)
+		return r;
+	rfbi_enable_clocks(1);
+
+	rfbi.l4_khz = clk_get_rate(rfbi.dss_ick) / 1000;
+
+	/* Reset */
+	rfbi_write_reg(RFBI_SYSCONFIG, 1 << 1);
+	while (!(rfbi_read_reg(RFBI_SYSSTATUS) & (1 << 0)));
+
+	l = rfbi_read_reg(RFBI_SYSCONFIG);
+	/* Enable autoidle and smart-idle */
+	l |= (1 << 0) | (2 << 3);
+	rfbi_write_reg(RFBI_SYSCONFIG, l);
+
+	/* 16-bit interface, ITE trigger mode, 16-bit data */
+	l = (0x03 << 0) | (0x00 << 2) | (0x01 << 5) | (0x02 << 7);
+	l |= (0 << 9) | (1 << 20) | (1 << 21);
+	rfbi_write_reg(RFBI_CONFIG0, l);
+
+	rfbi_write_reg(RFBI_DATA_CYCLE1_0, 0x00000010);
+
+	l = rfbi_read_reg(RFBI_CONTROL);
+	/* Select CS0, clear bypass mode */
+	l = (0x01 << 2);
+	rfbi_write_reg(RFBI_CONTROL, l);
+
+	if ((r = omap_dispc_request_irq(rfbi_dma_callback, NULL)) < 0) {
+		dev_err(fbdev->dev, "can't get DISPC irq\n");
+		rfbi_enable_clocks(0);
+		return r;
+	}
+
+	l = rfbi_read_reg(RFBI_REVISION);
+	pr_info("omapfb: RFBI version %d.%d initialized\n",
+		(l >> 4) & 0x0f, l & 0x0f);
+
+	rfbi_enable_clocks(0);
+
+	return 0;
+}
+
+static void rfbi_cleanup(void)
+{
+	omap_dispc_free_irq();
+	rfbi_put_clocks();
+}
+
+const struct lcd_ctrl_extif omap2_ext_if = {
+	.init			= rfbi_init,
+	.cleanup		= rfbi_cleanup,
+	.get_clk_info		= rfbi_get_clk_info,
+	.get_max_tx_rate	= rfbi_get_max_tx_rate,
+	.set_bits_per_cycle	= rfbi_set_bits_per_cycle,
+	.convert_timings	= rfbi_convert_timings,
+	.set_timings		= rfbi_set_timings,
+	.write_command		= rfbi_write_command,
+	.read_data		= rfbi_read_data,
+	.write_data		= rfbi_write_data,
+	.transfer_area		= rfbi_transfer_area,
+	.setup_tearsync		= rfbi_setup_tearsync,
+	.enable_tearsync	= rfbi_enable_tearsync,
+
+	.max_transmit_size	= (u32) ~0,
+};
+