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  1/*
  2 * Copyright (C) 2016 Marek Vasut <marex@denx.de>
  3 *
  4 * This code is based on drivers/video/fbdev/mxsfb.c :
  5 * Copyright (C) 2010 Juergen Beisert, Pengutronix
  6 * Copyright (C) 2008-2009 Freescale Semiconductor, Inc. All Rights Reserved.
  7 * Copyright (C) 2008 Embedded Alley Solutions, Inc All Rights Reserved.
  8 *
  9 * This program is free software; you can redistribute it and/or
 10 * modify it under the terms of the GNU General Public License
 11 * as published by the Free Software Foundation; either version 2
 12 * of the License, or (at your option) any later version.
 13 * This program is distributed in the hope that it will be useful,
 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 16 * GNU General Public License for more details.
 17 */
 18
 19#include <drm/drmP.h>
 20#include <drm/drm_atomic_helper.h>
 21#include <drm/drm_crtc.h>
 22#include <drm/drm_crtc_helper.h>
 23#include <drm/drm_fb_helper.h>
 24#include <drm/drm_fb_cma_helper.h>
 25#include <drm/drm_gem_cma_helper.h>
 26#include <drm/drm_of.h>
 27#include <drm/drm_plane_helper.h>
 28#include <drm/drm_simple_kms_helper.h>
 29#include <linux/clk.h>
 30#include <linux/iopoll.h>
 31#include <linux/of_graph.h>
 32#include <linux/platform_data/simplefb.h>
 33#include <video/videomode.h>
 34
 35#include "mxsfb_drv.h"
 36#include "mxsfb_regs.h"
 37
 38#define MXS_SET_ADDR		0x4
 39#define MXS_CLR_ADDR		0x8
 40#define MODULE_CLKGATE		BIT(30)
 41#define MODULE_SFTRST		BIT(31)
 42/* 1 second delay should be plenty of time for block reset */
 43#define RESET_TIMEOUT		1000000
 44
 45static u32 set_hsync_pulse_width(struct mxsfb_drm_private *mxsfb, u32 val)
 46{
 47	return (val & mxsfb->devdata->hs_wdth_mask) <<
 48		mxsfb->devdata->hs_wdth_shift;
 49}
 50
 51/* Setup the MXSFB registers for decoding the pixels out of the framebuffer */
 52static int mxsfb_set_pixel_fmt(struct mxsfb_drm_private *mxsfb)
 53{
 54	struct drm_crtc *crtc = &mxsfb->pipe.crtc;
 55	struct drm_device *drm = crtc->dev;
 56	const u32 format = crtc->primary->state->fb->format->format;
 57	u32 ctrl, ctrl1;
 58
 59	ctrl = CTRL_BYPASS_COUNT | CTRL_MASTER;
 60
 61	/*
 62	 * WARNING: The bus width, CTRL_SET_BUS_WIDTH(), is configured to
 63	 * match the selected mode here. This differs from the original
 64	 * MXSFB driver, which had the option to configure the bus width
 65	 * to arbitrary value. This limitation should not pose an issue.
 66	 */
 67
 68	/* CTRL1 contains IRQ config and status bits, preserve those. */
 69	ctrl1 = readl(mxsfb->base + LCDC_CTRL1);
 70	ctrl1 &= CTRL1_CUR_FRAME_DONE_IRQ_EN | CTRL1_CUR_FRAME_DONE_IRQ;
 71
 72	switch (format) {
 73	case DRM_FORMAT_RGB565:
 74		dev_dbg(drm->dev, "Setting up RGB565 mode\n");
 75		ctrl |= CTRL_SET_WORD_LENGTH(0);
 76		ctrl1 |= CTRL1_SET_BYTE_PACKAGING(0xf);
 77		break;
 78	case DRM_FORMAT_XRGB8888:
 79		dev_dbg(drm->dev, "Setting up XRGB8888 mode\n");
 80		ctrl |= CTRL_SET_WORD_LENGTH(3);
 81		/* Do not use packed pixels = one pixel per word instead. */
 82		ctrl1 |= CTRL1_SET_BYTE_PACKAGING(0x7);
 83		break;
 84	default:
 85		dev_err(drm->dev, "Unhandled pixel format %08x\n", format);
 86		return -EINVAL;
 87	}
 88
 89	writel(ctrl1, mxsfb->base + LCDC_CTRL1);
 90	writel(ctrl, mxsfb->base + LCDC_CTRL);
 91
 92	return 0;
 93}
 94
 95static void mxsfb_set_bus_fmt(struct mxsfb_drm_private *mxsfb)
 96{
 97	struct drm_crtc *crtc = &mxsfb->pipe.crtc;
 98	struct drm_device *drm = crtc->dev;
 99	u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
100	u32 reg;
101
102	reg = readl(mxsfb->base + LCDC_CTRL);
103
104	if (mxsfb->connector.display_info.num_bus_formats)
105		bus_format = mxsfb->connector.display_info.bus_formats[0];
106
107	reg &= ~CTRL_BUS_WIDTH_MASK;
108	switch (bus_format) {
109	case MEDIA_BUS_FMT_RGB565_1X16:
110		reg |= CTRL_SET_BUS_WIDTH(STMLCDIF_16BIT);
111		break;
112	case MEDIA_BUS_FMT_RGB666_1X18:
113		reg |= CTRL_SET_BUS_WIDTH(STMLCDIF_18BIT);
114		break;
115	case MEDIA_BUS_FMT_RGB888_1X24:
116		reg |= CTRL_SET_BUS_WIDTH(STMLCDIF_24BIT);
117		break;
118	default:
119		dev_err(drm->dev, "Unknown media bus format %d\n", bus_format);
120		break;
121	}
122	writel(reg, mxsfb->base + LCDC_CTRL);
123}
124
125static void mxsfb_enable_controller(struct mxsfb_drm_private *mxsfb)
126{
127	u32 reg;
128
129	if (mxsfb->clk_disp_axi)
130		clk_prepare_enable(mxsfb->clk_disp_axi);
131	clk_prepare_enable(mxsfb->clk);
132	mxsfb_enable_axi_clk(mxsfb);
133
134	/* If it was disabled, re-enable the mode again */
135	writel(CTRL_DOTCLK_MODE, mxsfb->base + LCDC_CTRL + REG_SET);
136
137	/* Enable the SYNC signals first, then the DMA engine */
138	reg = readl(mxsfb->base + LCDC_VDCTRL4);
139	reg |= VDCTRL4_SYNC_SIGNALS_ON;
140	writel(reg, mxsfb->base + LCDC_VDCTRL4);
141
142	writel(CTRL_RUN, mxsfb->base + LCDC_CTRL + REG_SET);
143}
144
145static void mxsfb_disable_controller(struct mxsfb_drm_private *mxsfb)
146{
147	u32 reg;
148
149	/*
150	 * Even if we disable the controller here, it will still continue
151	 * until its FIFOs are running out of data
152	 */
153	writel(CTRL_DOTCLK_MODE, mxsfb->base + LCDC_CTRL + REG_CLR);
154
155	readl_poll_timeout(mxsfb->base + LCDC_CTRL, reg, !(reg & CTRL_RUN),
156			   0, 1000);
157
158	reg = readl(mxsfb->base + LCDC_VDCTRL4);
159	reg &= ~VDCTRL4_SYNC_SIGNALS_ON;
160	writel(reg, mxsfb->base + LCDC_VDCTRL4);
161
162	mxsfb_disable_axi_clk(mxsfb);
163
164	clk_disable_unprepare(mxsfb->clk);
165	if (mxsfb->clk_disp_axi)
166		clk_disable_unprepare(mxsfb->clk_disp_axi);
167}
168
169/*
170 * Clear the bit and poll it cleared.  This is usually called with
171 * a reset address and mask being either SFTRST(bit 31) or CLKGATE
172 * (bit 30).
173 */
174static int clear_poll_bit(void __iomem *addr, u32 mask)
175{
176	u32 reg;
177
178	writel(mask, addr + MXS_CLR_ADDR);
179	return readl_poll_timeout(addr, reg, !(reg & mask), 0, RESET_TIMEOUT);
180}
181
182static int mxsfb_reset_block(void __iomem *reset_addr)
183{
184	int ret;
185
186	ret = clear_poll_bit(reset_addr, MODULE_SFTRST);
187	if (ret)
188		return ret;
189
190	writel(MODULE_CLKGATE, reset_addr + MXS_CLR_ADDR);
191
192	ret = clear_poll_bit(reset_addr, MODULE_SFTRST);
193	if (ret)
194		return ret;
195
196	return clear_poll_bit(reset_addr, MODULE_CLKGATE);
197}
198
199static void mxsfb_crtc_mode_set_nofb(struct mxsfb_drm_private *mxsfb)
200{
201	struct drm_display_mode *m = &mxsfb->pipe.crtc.state->adjusted_mode;
202	const u32 bus_flags = mxsfb->connector.display_info.bus_flags;
203	u32 vdctrl0, vsync_pulse_len, hsync_pulse_len;
204	int err;
205
206	/*
207	 * It seems, you can't re-program the controller if it is still
208	 * running. This may lead to shifted pictures (FIFO issue?), so
209	 * first stop the controller and drain its FIFOs.
210	 */
211	mxsfb_enable_axi_clk(mxsfb);
212
213	/* Mandatory eLCDIF reset as per the Reference Manual */
214	err = mxsfb_reset_block(mxsfb->base);
215	if (err)
216		return;
217
218	/* Clear the FIFOs */
219	writel(CTRL1_FIFO_CLEAR, mxsfb->base + LCDC_CTRL1 + REG_SET);
220
221	err = mxsfb_set_pixel_fmt(mxsfb);
222	if (err)
223		return;
224
225	clk_set_rate(mxsfb->clk, m->crtc_clock * 1000);
226
227	writel(TRANSFER_COUNT_SET_VCOUNT(m->crtc_vdisplay) |
228	       TRANSFER_COUNT_SET_HCOUNT(m->crtc_hdisplay),
229	       mxsfb->base + mxsfb->devdata->transfer_count);
230
231	vsync_pulse_len = m->crtc_vsync_end - m->crtc_vsync_start;
232
233	vdctrl0 = VDCTRL0_ENABLE_PRESENT |	/* Always in DOTCLOCK mode */
234		  VDCTRL0_VSYNC_PERIOD_UNIT |
235		  VDCTRL0_VSYNC_PULSE_WIDTH_UNIT |
236		  VDCTRL0_SET_VSYNC_PULSE_WIDTH(vsync_pulse_len);
237	if (m->flags & DRM_MODE_FLAG_PHSYNC)
238		vdctrl0 |= VDCTRL0_HSYNC_ACT_HIGH;
239	if (m->flags & DRM_MODE_FLAG_PVSYNC)
240		vdctrl0 |= VDCTRL0_VSYNC_ACT_HIGH;
241	/* Make sure Data Enable is high active by default */
242	if (!(bus_flags & DRM_BUS_FLAG_DE_LOW))
243		vdctrl0 |= VDCTRL0_ENABLE_ACT_HIGH;
244	/*
245	 * DRM_BUS_FLAG_PIXDATA_ defines are controller centric,
246	 * controllers VDCTRL0_DOTCLK is display centric.
247	 * Drive on positive edge       -> display samples on falling edge
248	 * DRM_BUS_FLAG_PIXDATA_POSEDGE -> VDCTRL0_DOTCLK_ACT_FALLING
249	 */
250	if (bus_flags & DRM_BUS_FLAG_PIXDATA_POSEDGE)
251		vdctrl0 |= VDCTRL0_DOTCLK_ACT_FALLING;
252
253	writel(vdctrl0, mxsfb->base + LCDC_VDCTRL0);
254
255	mxsfb_set_bus_fmt(mxsfb);
256
257	/* Frame length in lines. */
258	writel(m->crtc_vtotal, mxsfb->base + LCDC_VDCTRL1);
259
260	/* Line length in units of clocks or pixels. */
261	hsync_pulse_len = m->crtc_hsync_end - m->crtc_hsync_start;
262	writel(set_hsync_pulse_width(mxsfb, hsync_pulse_len) |
263	       VDCTRL2_SET_HSYNC_PERIOD(m->crtc_htotal),
264	       mxsfb->base + LCDC_VDCTRL2);
265
266	writel(SET_HOR_WAIT_CNT(m->crtc_htotal - m->crtc_hsync_start) |
267	       SET_VERT_WAIT_CNT(m->crtc_vtotal - m->crtc_vsync_start),
268	       mxsfb->base + LCDC_VDCTRL3);
269
270	writel(SET_DOTCLK_H_VALID_DATA_CNT(m->hdisplay),
271	       mxsfb->base + LCDC_VDCTRL4);
272
273	mxsfb_disable_axi_clk(mxsfb);
274}
275
276void mxsfb_crtc_enable(struct mxsfb_drm_private *mxsfb)
277{
278	mxsfb_crtc_mode_set_nofb(mxsfb);
279	mxsfb_enable_controller(mxsfb);
280}
281
282void mxsfb_crtc_disable(struct mxsfb_drm_private *mxsfb)
283{
284	mxsfb_disable_controller(mxsfb);
285}
286
287void mxsfb_plane_atomic_update(struct mxsfb_drm_private *mxsfb,
288			       struct drm_plane_state *state)
289{
290	struct drm_simple_display_pipe *pipe = &mxsfb->pipe;
291	struct drm_crtc *crtc = &pipe->crtc;
292	struct drm_framebuffer *fb = pipe->plane.state->fb;
293	struct drm_pending_vblank_event *event;
294	struct drm_gem_cma_object *gem;
295
296	if (!crtc)
297		return;
298
299	spin_lock_irq(&crtc->dev->event_lock);
300	event = crtc->state->event;
301	if (event) {
302		crtc->state->event = NULL;
303
304		if (drm_crtc_vblank_get(crtc) == 0) {
305			drm_crtc_arm_vblank_event(crtc, event);
306		} else {
307			drm_crtc_send_vblank_event(crtc, event);
308		}
309	}
310	spin_unlock_irq(&crtc->dev->event_lock);
311
312	if (!fb)
313		return;
314
315	gem = drm_fb_cma_get_gem_obj(fb, 0);
316
317	mxsfb_enable_axi_clk(mxsfb);
318	writel(gem->paddr, mxsfb->base + mxsfb->devdata->next_buf);
319	mxsfb_disable_axi_clk(mxsfb);
320}