// SPDX-License-Identifier: GPL-2.0-or-later
/*
* DRM driver for Pervasive Displays RePaper branded e-ink panels
*
* Copyright 2013-2017 Pervasive Displays, Inc.
* Copyright 2017 Noralf Trønnes
*
* The driver supports:
* Material Film: Aurora Mb (V231)
* Driver IC: G2 (eTC)
*
* The controller code was taken from the userspace driver:
* https://github.com/repaper/gratis
*/
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/property.h>
#include <linux/sched/clock.h>
#include <linux/spi/spi.h>
#include <linux/thermal.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_connector.h>
#include <drm/drm_damage_helper.h>
#include <drm/drm_drv.h>
#include <drm/drm_fb_dma_helper.h>
#include <drm/drm_fbdev_dma.h>
#include <drm/drm_format_helper.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_gem_atomic_helper.h>
#include <drm/drm_gem_dma_helper.h>
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_managed.h>
#include <drm/drm_modes.h>
#include <drm/drm_rect.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_simple_kms_helper.h>
#define REPAPER_RID_G2_COG_ID 0x12
enum repaper_model {
/* 0 is reserved to avoid clashing with NULL */
E1144CS021 = 1,
E1190CS021,
E2200CS021,
E2271CS021,
};
enum repaper_stage { /* Image pixel -> Display pixel */
REPAPER_COMPENSATE, /* B -> W, W -> B (Current Image) */
REPAPER_WHITE, /* B -> N, W -> W (Current Image) */
REPAPER_INVERSE, /* B -> N, W -> B (New Image) */
REPAPER_NORMAL /* B -> B, W -> W (New Image) */
};
enum repaper_epd_border_byte {
REPAPER_BORDER_BYTE_NONE,
REPAPER_BORDER_BYTE_ZERO,
REPAPER_BORDER_BYTE_SET,
};
struct repaper_epd {
struct drm_device drm;
struct drm_simple_display_pipe pipe;
const struct drm_display_mode *mode;
struct drm_connector connector;
struct spi_device *spi;
struct gpio_desc *panel_on;
struct gpio_desc *border;
struct gpio_desc *discharge;
struct gpio_desc *reset;
struct gpio_desc *busy;
struct thermal_zone_device *thermal;
unsigned int height;
unsigned int width;
unsigned int bytes_per_scan;
const u8 *channel_select;
unsigned int stage_time;
unsigned int factored_stage_time;
bool middle_scan;
bool pre_border_byte;
enum repaper_epd_border_byte border_byte;
u8 *line_buffer;
void *current_frame;
bool cleared;
bool partial;
};
static inline struct repaper_epd *drm_to_epd(struct drm_device *drm)
{
return container_of(drm, struct repaper_epd, drm);
}
static int repaper_spi_transfer(struct spi_device *spi, u8 header,
const void *tx, void *rx, size_t len)
{
void *txbuf = NULL, *rxbuf = NULL;
struct spi_transfer tr[2] = {};
u8 *headerbuf;
int ret;
headerbuf = kmalloc(1, GFP_KERNEL);
if (!headerbuf)
return -ENOMEM;
headerbuf[0] = header;
tr[0].tx_buf = headerbuf;
tr[0].len = 1;
/* Stack allocated tx? */
if (tx && len <= 32) {
txbuf = kmemdup(tx, len, GFP_KERNEL);
if (!txbuf) {
ret = -ENOMEM;
goto out_free;
}
}
if (rx) {
rxbuf = kmalloc(len, GFP_KERNEL);
if (!rxbuf) {
ret = -ENOMEM;
goto out_free;
}
}
tr[1].tx_buf = txbuf ? txbuf : tx;
tr[1].rx_buf = rxbuf;
tr[1].len = len;
ndelay(80);
ret = spi_sync_transfer(spi, tr, 2);
if (rx && !ret)
memcpy(rx, rxbuf, len);
out_free:
kfree(headerbuf);
kfree(txbuf);
kfree(rxbuf);
return ret;
}
static int repaper_write_buf(struct spi_device *spi, u8 reg,
const u8 *buf, size_t len)
{
int ret;
ret = repaper_spi_transfer(spi, 0x70, ®, NULL, 1);
if (ret)
return ret;
return repaper_spi_transfer(spi, 0x72, buf, NULL, len);
}
static int repaper_write_val(struct spi_device *spi, u8 reg, u8 val)
{
return repaper_write_buf(spi, reg, &val, 1);
}
static int repaper_read_val(struct spi_device *spi, u8 reg)
{
int ret;
u8 val;
ret = repaper_spi_transfer(spi, 0x70, ®, NULL, 1);
if (ret)
return ret;
ret = repaper_spi_transfer(spi, 0x73, NULL, &val, 1);
return ret ? ret : val;
}
static int repaper_read_id(struct spi_device *spi)
{
int ret;
u8 id;
ret = repaper_spi_transfer(spi, 0x71, NULL, &id, 1);
return ret ? ret : id;
}
static void repaper_spi_mosi_low(struct spi_device *spi)
{
const u8 buf[1] = { 0 };
spi_write(spi, buf, 1);
}
/* pixels on display are numbered from 1 so even is actually bits 1,3,5,... */
static void repaper_even_pixels(struct repaper_epd *epd, u8 **pp,
const u8 *data, u8 fixed_value, const u8 *mask,
enum repaper_stage stage)
{
unsigned int b;
for (b = 0; b < (epd->width / 8); b++) {
if (data) {
u8 pixels = data[b] & 0xaa;
u8 pixel_mask = 0xff;
u8 p1, p2, p3, p4;
if (mask) {
pixel_mask = (mask[b] ^ pixels) & 0xaa;
pixel_mask |= pixel_mask >> 1;
}
switch (stage) {
case REPAPER_COMPENSATE: /* B -> W, W -> B (Current) */
pixels = 0xaa | ((pixels ^ 0xaa) >> 1);
break;
case REPAPER_WHITE: /* B -> N, W -> W (Current) */
pixels = 0x55 + ((pixels ^ 0xaa) >> 1);
break;
case REPAPER_INVERSE: /* B -> N, W -> B (New) */
pixels = 0x55 | (pixels ^ 0xaa);
break;
case REPAPER_NORMAL: /* B -> B, W -> W (New) */
pixels = 0xaa | (pixels >> 1);
break;
}
pixels = (pixels & pixel_mask) | (~pixel_mask & 0x55);
p1 = (pixels >> 6) & 0x03;
p2 = (pixels >> 4) & 0x03;
p3 = (pixels >> 2) & 0x03;
p4 = (pixels >> 0) & 0x03;
pixels = (p1 << 0) | (p2 << 2) | (p3 << 4) | (p4 << 6);
*(*pp)++ = pixels;
} else {
*(*pp)++ = fixed_value;
}
}
}
/* pixels on display are numbered from 1 so odd is actually bits 0,2,4,... */
static void repaper_odd_pixels(struct repaper_epd *epd, u8 **pp,
const u8 *data, u8 fixed_value, const u8 *mask,
enum repaper_stage stage)
{
unsigned int b;
for (b = epd->width / 8; b > 0; b--) {
if (data) {
u8 pixels = data[b - 1] & 0x55;
u8 pixel_mask = 0xff;
if (mask) {
pixel_mask = (mask[b - 1] ^ pixels) & 0x55;
pixel_mask |= pixel_mask << 1;
}
switch (stage) {
case REPAPER_COMPENSATE: /* B -> W, W -> B (Current) */
pixels = 0xaa | (pixels ^ 0x55);
break;
case REPAPER_WHITE: /* B -> N, W -> W (Current) */
pixels = 0x55 + (pixels ^ 0x55);
break;
case REPAPER_INVERSE: /* B -> N, W -> B (New) */
pixels = 0x55 | ((pixels ^ 0x55) << 1);
break;
case REPAPER_NORMAL: /* B -> B, W -> W (New) */
pixels = 0xaa | pixels;
break;
}
pixels = (pixels & pixel_mask) | (~pixel_mask & 0x55);
*(*pp)++ = pixels;
} else {
*(*pp)++ = fixed_value;
}
}
}
/* interleave bits: (byte)76543210 -> (16 bit).7.6.5.4.3.2.1 */
static inline u16 repaper_interleave_bits(u16 value)
{
value = (value | (value << 4)) & 0x0f0f;
value = (value | (value << 2)) & 0x3333;
value = (value | (value << 1)) & 0x5555;
return value;
}
/* pixels on display are numbered from 1 */
static void repaper_all_pixels(struct repaper_epd *epd, u8 **pp,
const u8 *data, u8 fixed_value, const u8 *mask,
enum repaper_stage stage)
{
unsigned int b;
for (b = epd->width / 8; b > 0; b--) {
if (data) {
u16 pixels = repaper_interleave_bits(data[b - 1]);
u16 pixel_mask = 0xffff;
if (mask) {
pixel_mask = repaper_interleave_bits(mask[b - 1]);
pixel_mask = (pixel_mask ^ pixels) & 0x5555;
pixel_mask |= pixel_mask << 1;
}
switch (stage) {
case REPAPER_COMPENSATE: /* B -> W, W -> B (Current) */
pixels = 0xaaaa | (pixels ^ 0x5555);
break;
case REPAPER_WHITE: /* B -> N, W -> W (Current) */
pixels = 0x5555 + (pixels ^ 0x5555);
break;
case REPAPER_INVERSE: /* B -> N, W -> B (New) */
pixels = 0x5555 | ((pixels ^ 0x5555) << 1);
break;
case REPAPER_NORMAL: /* B -> B, W -> W (New) */
pixels = 0xaaaa | pixels;
break;
}
pixels = (pixels & pixel_mask) | (~pixel_mask & 0x5555);
*(*pp)++ = pixels >> 8;
*(*pp)++ = pixels;
} else {
*(*pp)++ = fixed_value;
*(*pp)++ = fixed_value;
}
}
}
/* output one line of scan and data bytes to the display */
static void repaper_one_line(struct repaper_epd *epd, unsigned int line,
const u8 *data, u8 fixed_value, const u8 *mask,
enum repaper_stage stage)
{
u8 *p = epd->line_buffer;
unsigned int b;
repaper_spi_mosi_low(epd->spi);
if (epd->pre_border_byte)
*p++ = 0x00;
if (epd->middle_scan) {
/* data bytes */
repaper_odd_pixels(epd, &p, data, fixed_value, mask, stage);
/* scan line */
for (b = epd->bytes_per_scan; b > 0; b--) {
if (line / 4 == b - 1)
*p++ = 0x03 << (2 * (line & 0x03));
else
*p++ = 0x00;
}
/* data bytes */
repaper_even_pixels(epd, &p, data, fixed_value, mask, stage);
} else {
/*
* even scan line, but as lines on display are numbered from 1,
* line: 1,3,5,...
*/
for (b = 0; b < epd->bytes_per_scan; b++) {
if (0 != (line & 0x01) && line / 8 == b)
*p++ = 0xc0 >> (line & 0x06);
else
*p++ = 0x00;
}
/* data bytes */
repaper_all_pixels(epd, &p, data, fixed_value, mask, stage);
/*
* odd scan line, but as lines on display are numbered from 1,
* line: 0,2,4,6,...
*/
for (b = epd->bytes_per_scan; b > 0; b--) {
if (0 == (line & 0x01) && line / 8 == b - 1)
*p++ = 0x03 << (line & 0x06);
else
*p++ = 0x00;
}
}
switch (epd->border_byte) {
case REPAPER_BORDER_BYTE_NONE:
break;
case REPAPER_BORDER_BYTE_ZERO:
*p++ = 0x00;
break;
case REPAPER_BORDER_BYTE_SET:
switch (stage) {
case REPAPER_COMPENSATE:
case REPAPER_WHITE:
case REPAPER_INVERSE:
*p++ = 0x00;
break;
case REPAPER_NORMAL:
*p++ = 0xaa;
break;
}
break;
}
repaper_write_buf(epd->spi, 0x0a, epd->line_buffer,
p - epd->line_buffer);
/* Output data to panel */
repaper_write_val(epd->spi, 0x02, 0x07);
repaper_spi_mosi_low(epd->spi);
}
static void repaper_frame_fixed(struct repaper_epd *epd, u8 fixed_value,
enum repaper_stage stage)
{
unsigned int line;
for (line = 0; line < epd->height; line++)
repaper_one_line(epd, line, NULL, fixed_value, NULL, stage);
}
static void repaper_frame_data(struct repaper_epd *epd, const u8 *image,
const u8 *mask, enum repaper_stage stage)
{
unsigned int line;
if (!mask) {
for (line = 0; line < epd->height; line++) {
repaper_one_line(epd, line,
&image[line * (epd->width / 8)],
0, NULL, stage);
}
} else {
for (line = 0; line < epd->height; line++) {
size_t n = line * epd->width / 8;
repaper_one_line(epd, line, &image[n], 0, &mask[n],
stage);
}
}
}
static void repaper_frame_fixed_repeat(struct repaper_epd *epd, u8 fixed_value,
enum repaper_stage stage)
{
u64 start = local_clock();
u64 end = start + (epd->factored_stage_time * 1000 * 1000);
do {
repaper_frame_fixed(epd, fixed_value, stage);
} while (local_clock() < end);
}
static void repaper_frame_data_repeat(struct repaper_epd *epd, const u8 *image,
const u8 *mask, enum repaper_stage stage)
{
u64 start = local_clock();
u64 end = start + (epd->factored_stage_time * 1000 * 1000);
do {
repaper_frame_data(epd, image, mask, stage);
} while (local_clock() < end);
}
static void repaper_get_temperature(struct repaper_epd *epd)
{
int ret, temperature = 0;
unsigned int factor10x;
if (!epd->thermal)
return;
ret = thermal_zone_get_temp(epd->thermal, &temperature);
if (ret) {
DRM_DEV_ERROR(&epd->spi->dev, "Failed to get temperature (%d)\n", ret);
return;
}
temperature /= 1000;
if (temperature <= -10)
factor10x = 170;
else if (temperature <= -5)
factor10x = 120;
else if (temperature <= 5)
factor10x = 80;
else if (temperature <= 10)
factor10x = 40;
else if (temperature <= 15)
factor10x = 30;
else if (temperature <= 20)
factor10x = 20;
else if (temperature <= 40)
factor10x = 10;
else
factor10x = 7;
epd->factored_stage_time = epd->stage_time * factor10x / 10;
}
static int repaper_fb_dirty(struct drm_framebuffer *fb,
struct drm_format_conv_state *fmtcnv_state)
{
struct drm_gem_dma_object *dma_obj = drm_fb_dma_get_gem_obj(fb, 0);
struct repaper_epd *epd = drm_to_epd(fb->dev);
unsigned int dst_pitch = 0;
struct iosys_map dst, vmap;
struct drm_rect clip;
int idx, ret = 0;
u8 *buf = NULL;
if (!drm_dev_enter(fb->dev, &idx))
return -ENODEV;
/* repaper can't do partial updates */
clip.x1 = 0;
clip.x2 = fb->width;
clip.y1 = 0;
clip.y2 = fb->height;
repaper_get_temperature(epd);
DRM_DEBUG("Flushing [FB:%d] st=%ums\n", fb->base.id,
epd->factored_stage_time);
buf = kmalloc(fb->width * fb->height / 8, GFP_KERNEL);
if (!buf) {
ret = -ENOMEM;
goto out_exit;
}
ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
if (ret)
goto out_free;
iosys_map_set_vaddr(&dst, buf);
iosys_map_set_vaddr(&vmap, dma_obj->vaddr);
drm_fb_xrgb8888_to_mono(&dst, &dst_pitch, &vmap, fb, &clip, fmtcnv_state);
drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
if (epd->partial) {
repaper_frame_data_repeat(epd, buf, epd->current_frame,
REPAPER_NORMAL);
} else if (epd->cleared) {
repaper_frame_data_repeat(epd, epd->current_frame, NULL,
REPAPER_COMPENSATE);
repaper_frame_data_repeat(epd, epd->current_frame, NULL,
REPAPER_WHITE);
repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE);
repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL);
epd->partial = true;
} else {
/* Clear display (anything -> white) */
repaper_frame_fixed_repeat(epd, 0xff, REPAPER_COMPENSATE);
repaper_frame_fixed_repeat(epd, 0xff, REPAPER_WHITE);
repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_INVERSE);
repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_NORMAL);
/* Assuming a clear (white) screen output an image */
repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_COMPENSATE);
repaper_frame_fixed_repeat(epd, 0xaa, REPAPER_WHITE);
repaper_frame_data_repeat(epd, buf, NULL, REPAPER_INVERSE);
repaper_frame_data_repeat(epd, buf, NULL, REPAPER_NORMAL);
epd->cleared = true;
epd->partial = true;
}
memcpy(epd->current_frame, buf, fb->width * fb->height / 8);
/*
* An extra frame write is needed if pixels are set in the bottom line,
* or else grey lines rises up from the pixels
*/
if (epd->pre_border_byte) {
unsigned int x;
for (x = 0; x < (fb->width / 8); x++)
if (buf[x + (fb->width * (fb->height - 1) / 8)]) {
repaper_frame_data_repeat(epd, buf,
epd->current_frame,
REPAPER_NORMAL);
break;
}
}
out_free:
kfree(buf);
out_exit:
drm_dev_exit(idx);
return ret;
}
static void power_off(struct repaper_epd *epd)
{
/* Turn off power and all signals */
gpiod_set_value_cansleep(epd->reset, 0);
gpiod_set_value_cansleep(epd->panel_on, 0);
if (epd->border)
gpiod_set_value_cansleep(epd->border, 0);
/* Ensure SPI MOSI and CLOCK are Low before CS Low */
repaper_spi_mosi_low(epd->spi);
/* Discharge pulse */
gpiod_set_value_cansleep(epd->discharge, 1);
msleep(150);
gpiod_set_value_cansleep(epd->discharge, 0);
}
static enum drm_mode_status repaper_pipe_mode_valid(struct drm_simple_display_pipe *pipe,
const struct drm_display_mode *mode)
{
struct drm_crtc *crtc = &pipe->crtc;
struct repaper_epd *epd = drm_to_epd(crtc->dev);
return drm_crtc_helper_mode_valid_fixed(crtc, mode, epd->mode);
}
static void repaper_pipe_enable(struct drm_simple_display_pipe *pipe,
struct drm_crtc_state *crtc_state,
struct drm_plane_state *plane_state)
{
struct repaper_epd *epd = drm_to_epd(pipe->crtc.dev);
struct spi_device *spi = epd->spi;
struct device *dev = &spi->dev;
bool dc_ok = false;
int i, ret, idx;
if (!drm_dev_enter(pipe->crtc.dev, &idx))
return;
DRM_DEBUG_DRIVER("\n");
/* Power up sequence */
gpiod_set_value_cansleep(epd->reset, 0);
gpiod_set_value_cansleep(epd->panel_on, 0);
gpiod_set_value_cansleep(epd->discharge, 0);
if (epd->border)
gpiod_set_value_cansleep(epd->border, 0);
repaper_spi_mosi_low(spi);
usleep_range(5000, 10000);
gpiod_set_value_cansleep(epd->panel_on, 1);
/*
* This delay comes from the repaper.org userspace driver, it's not
* mentioned in the datasheet.
*/
usleep_range(10000, 15000);
gpiod_set_value_cansleep(epd->reset, 1);
if (epd->border)
gpiod_set_value_cansleep(epd->border, 1);
usleep_range(5000, 10000);
gpiod_set_value_cansleep(epd->reset, 0);
usleep_range(5000, 10000);
gpiod_set_value_cansleep(epd->reset, 1);
usleep_range(5000, 10000);
/* Wait for COG to become ready */
for (i = 100; i > 0; i--) {
if (!gpiod_get_value_cansleep(epd->busy))
break;
usleep_range(10, 100);
}
if (!i) {
DRM_DEV_ERROR(dev, "timeout waiting for panel to become ready.\n");
power_off(epd);
goto out_exit;
}
repaper_read_id(spi);
ret = repaper_read_id(spi);
if (ret != REPAPER_RID_G2_COG_ID) {
if (ret < 0)
dev_err(dev, "failed to read chip (%d)\n", ret);
else
dev_err(dev, "wrong COG ID 0x%02x\n", ret);
power_off(epd);
goto out_exit;
}
/* Disable OE */
repaper_write_val(spi, 0x02, 0x40);
ret = repaper_read_val(spi, 0x0f);
if (ret < 0 || !(ret & 0x80)) {
if (ret < 0)
DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret);
else
DRM_DEV_ERROR(dev, "panel is reported broken\n");
power_off(epd);
goto out_exit;
}
/* Power saving mode */
repaper_write_val(spi, 0x0b, 0x02);
/* Channel select */
repaper_write_buf(spi, 0x01, epd->channel_select, 8);
/* High power mode osc */
repaper_write_val(spi, 0x07, 0xd1);
/* Power setting */
repaper_write_val(spi, 0x08, 0x02);
/* Vcom level */
repaper_write_val(spi, 0x09, 0xc2);
/* Power setting */
repaper_write_val(spi, 0x04, 0x03);
/* Driver latch on */
repaper_write_val(spi, 0x03, 0x01);
/* Driver latch off */
repaper_write_val(spi, 0x03, 0x00);
usleep_range(5000, 10000);
/* Start chargepump */
for (i = 0; i < 4; ++i) {
/* Charge pump positive voltage on - VGH/VDL on */
repaper_write_val(spi, 0x05, 0x01);
msleep(240);
/* Charge pump negative voltage on - VGL/VDL on */
repaper_write_val(spi, 0x05, 0x03);
msleep(40);
/* Charge pump Vcom on - Vcom driver on */
repaper_write_val(spi, 0x05, 0x0f);
msleep(40);
/* check DC/DC */
ret = repaper_read_val(spi, 0x0f);
if (ret < 0) {
DRM_DEV_ERROR(dev, "failed to read chip (%d)\n", ret);
power_off(epd);
goto out_exit;
}
if (ret & 0x40) {
dc_ok = true;
break;
}
}
if (!dc_ok) {
DRM_DEV_ERROR(dev, "dc/dc failed\n");
power_off(epd);
goto out_exit;
}
/*
* Output enable to disable
* The userspace driver sets this to 0x04, but the datasheet says 0x06
*/
repaper_write_val(spi, 0x02, 0x04);
epd->partial = false;
out_exit:
drm_dev_exit(idx);
}
static void repaper_pipe_disable(struct drm_simple_display_pipe *pipe)
{
struct repaper_epd *epd = drm_to_epd(pipe->crtc.dev);
struct spi_device *spi = epd->spi;
unsigned int line;
/*
* This callback is not protected by drm_dev_enter/exit since we want to
* turn off the display on regular driver unload. It's highly unlikely
* that the underlying SPI controller is gone should this be called after
* unplug.
*/
DRM_DEBUG_DRIVER("\n");
/* Nothing frame */
for (line = 0; line < epd->height; line++)
repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
REPAPER_COMPENSATE);
/* 2.7" */
if (epd->border) {
/* Dummy line */
repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
REPAPER_COMPENSATE);
msleep(25);
gpiod_set_value_cansleep(epd->border, 0);
msleep(200);
gpiod_set_value_cansleep(epd->border, 1);
} else {
/* Border dummy line */
repaper_one_line(epd, 0x7fffu, NULL, 0x00, NULL,
REPAPER_NORMAL);
msleep(200);
}
/* not described in datasheet */
repaper_write_val(spi, 0x0b, 0x00);
/* Latch reset turn on */
repaper_write_val(spi, 0x03, 0x01);
/* Power off charge pump Vcom */
repaper_write_val(spi, 0x05, 0x03);
/* Power off charge pump neg voltage */
repaper_write_val(spi, 0x05, 0x01);
msleep(120);
/* Discharge internal */
repaper_write_val(spi, 0x04, 0x80);
/* turn off all charge pumps */
repaper_write_val(spi, 0x05, 0x00);
/* Turn off osc */
repaper_write_val(spi, 0x07, 0x01);
msleep(50);
power_off(epd);
}
static void repaper_pipe_update(struct drm_simple_display_pipe *pipe,
struct drm_plane_state *old_state)
{
struct drm_plane_state *state = pipe->plane.state;
struct drm_format_conv_state fmtcnv_state = DRM_FORMAT_CONV_STATE_INIT;
struct drm_rect rect;
if (!pipe->crtc.state->active)
return;
if (drm_atomic_helper_damage_merged(old_state, state, &rect))
repaper_fb_dirty(state->fb, &fmtcnv_state);
drm_format_conv_state_release(&fmtcnv_state);
}
static const struct drm_simple_display_pipe_funcs repaper_pipe_funcs = {
.mode_valid = repaper_pipe_mode_valid,
.enable = repaper_pipe_enable,
.disable = repaper_pipe_disable,
.update = repaper_pipe_update,
};
static int repaper_connector_get_modes(struct drm_connector *connector)
{
struct repaper_epd *epd = drm_to_epd(connector->dev);
return drm_connector_helper_get_modes_fixed(connector, epd->mode);
}
static const struct drm_connector_helper_funcs repaper_connector_hfuncs = {
.get_modes = repaper_connector_get_modes,
};
static const struct drm_connector_funcs repaper_connector_funcs = {
.reset = drm_atomic_helper_connector_reset,
.fill_modes = drm_helper_probe_single_connector_modes,
.destroy = drm_connector_cleanup,
.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
};
static const struct drm_mode_config_funcs repaper_mode_config_funcs = {
.fb_create = drm_gem_fb_create_with_dirty,
.atomic_check = drm_atomic_helper_check,
.atomic_commit = drm_atomic_helper_commit,
};
static const uint32_t repaper_formats[] = {
DRM_FORMAT_XRGB8888,
};
static const struct drm_display_mode repaper_e1144cs021_mode = {
DRM_SIMPLE_MODE(128, 96, 29, 22),
};
static const u8 repaper_e1144cs021_cs[] = { 0x00, 0x00, 0x00, 0x00,
0x00, 0x0f, 0xff, 0x00 };
static const struct drm_display_mode repaper_e1190cs021_mode = {
DRM_SIMPLE_MODE(144, 128, 36, 32),
};
static const u8 repaper_e1190cs021_cs[] = { 0x00, 0x00, 0x00, 0x03,
0xfc, 0x00, 0x00, 0xff };
static const struct drm_display_mode repaper_e2200cs021_mode = {
DRM_SIMPLE_MODE(200, 96, 46, 22),
};
static const u8 repaper_e2200cs021_cs[] = { 0x00, 0x00, 0x00, 0x00,
0x01, 0xff, 0xe0, 0x00 };
static const struct drm_display_mode repaper_e2271cs021_mode = {
DRM_SIMPLE_MODE(264, 176, 57, 38),
};
static const u8 repaper_e2271cs021_cs[] = { 0x00, 0x00, 0x00, 0x7f,
0xff, 0xfe, 0x00, 0x00 };
DEFINE_DRM_GEM_DMA_FOPS(repaper_fops);
static const struct drm_driver repaper_driver = {
.driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
.fops = &repaper_fops,
DRM_GEM_DMA_DRIVER_OPS_VMAP,
.name = "repaper",
.desc = "Pervasive Displays RePaper e-ink panels",
.date = "20170405",
.major = 1,
.minor = 0,
};
static const struct of_device_id repaper_of_match[] = {
{ .compatible = "pervasive,e1144cs021", .data = (void *)E1144CS021 },
{ .compatible = "pervasive,e1190cs021", .data = (void *)E1190CS021 },
{ .compatible = "pervasive,e2200cs021", .data = (void *)E2200CS021 },
{ .compatible = "pervasive,e2271cs021", .data = (void *)E2271CS021 },
{},
};
MODULE_DEVICE_TABLE(of, repaper_of_match);
static const struct spi_device_id repaper_id[] = {
{ "e1144cs021", E1144CS021 },
{ "e1190cs021", E1190CS021 },
{ "e2200cs021", E2200CS021 },
{ "e2271cs021", E2271CS021 },
{ },
};
MODULE_DEVICE_TABLE(spi, repaper_id);
static int repaper_probe(struct spi_device *spi)
{
const struct drm_display_mode *mode;
const struct spi_device_id *spi_id;
struct device *dev = &spi->dev;
enum repaper_model model;
const char *thermal_zone;
struct repaper_epd *epd;
size_t line_buffer_size;
struct drm_device *drm;
const void *match;
int ret;
match = device_get_match_data(dev);
if (match) {
model = (enum repaper_model)(uintptr_t)match;
} else {
spi_id = spi_get_device_id(spi);
model = (enum repaper_model)spi_id->driver_data;
}
/* The SPI device is used to allocate dma memory */
if (!dev->coherent_dma_mask) {
ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
if (ret) {
dev_warn(dev, "Failed to set dma mask %d\n", ret);
return ret;
}
}
epd = devm_drm_dev_alloc(dev, &repaper_driver,
struct repaper_epd, drm);
if (IS_ERR(epd))
return PTR_ERR(epd);
drm = &epd->drm;
ret = drmm_mode_config_init(drm);
if (ret)
return ret;
drm->mode_config.funcs = &repaper_mode_config_funcs;
epd->spi = spi;
epd->panel_on = devm_gpiod_get(dev, "panel-on", GPIOD_OUT_LOW);
if (IS_ERR(epd->panel_on)) {
ret = PTR_ERR(epd->panel_on);
if (ret != -EPROBE_DEFER)
DRM_DEV_ERROR(dev, "Failed to get gpio 'panel-on'\n");
return ret;
}
epd->discharge = devm_gpiod_get(dev, "discharge", GPIOD_OUT_LOW);
if (IS_ERR(epd->discharge)) {
ret = PTR_ERR(epd->discharge);
if (ret != -EPROBE_DEFER)
DRM_DEV_ERROR(dev, "Failed to get gpio 'discharge'\n");
return ret;
}
epd->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
if (IS_ERR(epd->reset)) {
ret = PTR_ERR(epd->reset);
if (ret != -EPROBE_DEFER)
DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n");
return ret;
}
epd->busy = devm_gpiod_get(dev, "busy", GPIOD_IN);
if (IS_ERR(epd->busy)) {
ret = PTR_ERR(epd->busy);
if (ret != -EPROBE_DEFER)
DRM_DEV_ERROR(dev, "Failed to get gpio 'busy'\n");
return ret;
}
if (!device_property_read_string(dev, "pervasive,thermal-zone",
&thermal_zone)) {
epd->thermal = thermal_zone_get_zone_by_name(thermal_zone);
if (IS_ERR(epd->thermal)) {
DRM_DEV_ERROR(dev, "Failed to get thermal zone: %s\n", thermal_zone);
return PTR_ERR(epd->thermal);
}
}
switch (model) {
case E1144CS021:
mode = &repaper_e1144cs021_mode;
epd->channel_select = repaper_e1144cs021_cs;
epd->stage_time = 480;
epd->bytes_per_scan = 96 / 4;
epd->middle_scan = true; /* data-scan-data */
epd->pre_border_byte = false;
epd->border_byte = REPAPER_BORDER_BYTE_ZERO;
break;
case E1190CS021:
mode = &repaper_e1190cs021_mode;
epd->channel_select = repaper_e1190cs021_cs;
epd->stage_time = 480;
epd->bytes_per_scan = 128 / 4 / 2;
epd->middle_scan = false; /* scan-data-scan */
epd->pre_border_byte = false;
epd->border_byte = REPAPER_BORDER_BYTE_SET;
break;
case E2200CS021:
mode = &repaper_e2200cs021_mode;
epd->channel_select = repaper_e2200cs021_cs;
epd->stage_time = 480;
epd->bytes_per_scan = 96 / 4;
epd->middle_scan = true; /* data-scan-data */
epd->pre_border_byte = true;
epd->border_byte = REPAPER_BORDER_BYTE_NONE;
break;
case E2271CS021:
epd->border = devm_gpiod_get(dev, "border", GPIOD_OUT_LOW);
if (IS_ERR(epd->border)) {
ret = PTR_ERR(epd->border);
if (ret != -EPROBE_DEFER)
DRM_DEV_ERROR(dev, "Failed to get gpio 'border'\n");
return ret;
}
mode = &repaper_e2271cs021_mode;
epd->channel_select = repaper_e2271cs021_cs;
epd->stage_time = 630;
epd->bytes_per_scan = 176 / 4;
epd->middle_scan = true; /* data-scan-data */
epd->pre_border_byte = true;
epd->border_byte = REPAPER_BORDER_BYTE_NONE;
break;
default:
return -ENODEV;
}
epd->mode = mode;
epd->width = mode->hdisplay;
epd->height = mode->vdisplay;
epd->factored_stage_time = epd->stage_time;
line_buffer_size = 2 * epd->width / 8 + epd->bytes_per_scan + 2;
epd->line_buffer = devm_kzalloc(dev, line_buffer_size, GFP_KERNEL);
if (!epd->line_buffer)
return -ENOMEM;
epd->current_frame = devm_kzalloc(dev, epd->width * epd->height / 8,
GFP_KERNEL);
if (!epd->current_frame)
return -ENOMEM;
drm->mode_config.min_width = mode->hdisplay;
drm->mode_config.max_width = mode->hdisplay;
drm->mode_config.min_height = mode->vdisplay;
drm->mode_config.max_height = mode->vdisplay;
drm_connector_helper_add(&epd->connector, &repaper_connector_hfuncs);
ret = drm_connector_init(drm, &epd->connector, &repaper_connector_funcs,
DRM_MODE_CONNECTOR_SPI);
if (ret)
return ret;
ret = drm_simple_display_pipe_init(drm, &epd->pipe, &repaper_pipe_funcs,
repaper_formats, ARRAY_SIZE(repaper_formats),
NULL, &epd->connector);
if (ret)
return ret;
drm_mode_config_reset(drm);
ret = drm_dev_register(drm, 0);
if (ret)
return ret;
spi_set_drvdata(spi, drm);
DRM_DEBUG_DRIVER("SPI speed: %uMHz\n", spi->max_speed_hz / 1000000);
drm_fbdev_dma_setup(drm, 0);
return 0;
}
static void repaper_remove(struct spi_device *spi)
{
struct drm_device *drm = spi_get_drvdata(spi);
drm_dev_unplug(drm);
drm_atomic_helper_shutdown(drm);
}
static void repaper_shutdown(struct spi_device *spi)
{
drm_atomic_helper_shutdown(spi_get_drvdata(spi));
}
static struct spi_driver repaper_spi_driver = {
.driver = {
.name = "repaper",
.of_match_table = repaper_of_match,
},
.id_table = repaper_id,
.probe = repaper_probe,
.remove = repaper_remove,
.shutdown = repaper_shutdown,
};
module_spi_driver(repaper_spi_driver);
MODULE_DESCRIPTION("Pervasive Displays RePaper DRM driver");
MODULE_AUTHOR("Noralf Trønnes");
MODULE_LICENSE("GPL");
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