[PATCH v2 4/4] drm/tinydrm: Add RePaper e-ink driver
Noralf Trønnes
noralf at tronnes.org
Wed Jun 28 14:27:25 UTC 2017
Den 26.06.2017 11.49, skrev Daniel Vetter:
> On Thu, Jun 08, 2017 at 05:14:35PM +0200, Noralf Trønnes wrote:
>> This adds support for the Pervasive Displays RePaper branded displays.
>> The controller code is taken from the userspace driver available
>> through repaper.org. Only the V231 film is supported since the others
>> are EOL.
>>
>> Signed-off-by: Noralf Trønnes <noralf at tronnes.org>
> I took a look, and besides the tinydrm issues we've capture already this
> all looks reasonable.
>
> Acked-by: Daniel Vetter <daniel.vetter at ffwll.ch>
>
> Yes I'm trying once more to sign you up for drm-misc commit rights, hence
> not pushing ...
Ok, I'll apply for an account :-)
Thanks for reviewing.
Noralf.
> -Daniel
>> ---
>> MAINTAINERS | 6 +
>> drivers/gpu/drm/tinydrm/Kconfig | 12 +
>> drivers/gpu/drm/tinydrm/Makefile | 1 +
>> drivers/gpu/drm/tinydrm/repaper.c | 1095 +++++++++++++++++++++++++++++++++++++
>> 4 files changed, 1114 insertions(+)
>> create mode 100644 drivers/gpu/drm/tinydrm/repaper.c
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 757d487..800afa2 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -4446,6 +4446,12 @@ M: Dave Airlie <airlied at redhat.com>
>> S: Odd Fixes
>> F: drivers/gpu/drm/mgag200/
>>
>> +DRM DRIVER FOR PERVASIVE DISPLAYS REPAPER PANELS
>> +M: Noralf Trønnes <noralf at tronnes.org>
>> +S: Maintained
>> +F: drivers/gpu/drm/tinydrm/repaper.c
>> +F: Documentation/devicetree/bindings/display/repaper.txt
>> +
>> DRM DRIVER FOR RAGE 128 VIDEO CARDS
>> S: Orphan / Obsolete
>> F: drivers/gpu/drm/r128/
>> diff --git a/drivers/gpu/drm/tinydrm/Kconfig b/drivers/gpu/drm/tinydrm/Kconfig
>> index 3504c53..9596e44 100644
>> --- a/drivers/gpu/drm/tinydrm/Kconfig
>> +++ b/drivers/gpu/drm/tinydrm/Kconfig
>> @@ -19,3 +19,15 @@ config TINYDRM_MI0283QT
>> help
>> DRM driver for the Multi-Inno MI0283QT display panel
>> If M is selected the module will be called mi0283qt.
>> +
>> +config TINYDRM_REPAPER
>> + tristate "DRM support for Pervasive Displays RePaper panels (V231)"
>> + depends on DRM_TINYDRM && SPI
>> + help
>> + DRM driver for the following Pervasive Displays panels:
>> + 1.44" TFT EPD Panel (E1144CS021)
>> + 1.90" TFT EPD Panel (E1190CS021)
>> + 2.00" TFT EPD Panel (E2200CS021)
>> + 2.71" TFT EPD Panel (E2271CS021)
>> +
>> + If M is selected the module will be called repaper.
>> diff --git a/drivers/gpu/drm/tinydrm/Makefile b/drivers/gpu/drm/tinydrm/Makefile
>> index 7a3604c..95bb4d4 100644
>> --- a/drivers/gpu/drm/tinydrm/Makefile
>> +++ b/drivers/gpu/drm/tinydrm/Makefile
>> @@ -5,3 +5,4 @@ obj-$(CONFIG_TINYDRM_MIPI_DBI) += mipi-dbi.o
>>
>> # Displays
>> obj-$(CONFIG_TINYDRM_MI0283QT) += mi0283qt.o
>> +obj-$(CONFIG_TINYDRM_REPAPER) += repaper.o
>> diff --git a/drivers/gpu/drm/tinydrm/repaper.c b/drivers/gpu/drm/tinydrm/repaper.c
>> new file mode 100644
>> index 0000000..3343d3f
>> --- /dev/null
>> +++ b/drivers/gpu/drm/tinydrm/repaper.c
>> @@ -0,0 +1,1095 @@
>> +/*
>> + * 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
>> + *
>> + * 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.
>> + */
>> +
>> +#include <linux/delay.h>
>> +#include <linux/gpio/consumer.h>
>> +#include <linux/module.h>
>> +#include <linux/of_device.h>
>> +#include <linux/sched/clock.h>
>> +#include <linux/spi/spi.h>
>> +#include <linux/thermal.h>
>> +
>> +#include <drm/tinydrm/tinydrm.h>
>> +#include <drm/tinydrm/tinydrm-helpers.h>
>> +
>> +#define REPAPER_RID_G2_COG_ID 0x12
>> +
>> +enum repaper_model {
>> + 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 tinydrm_device tinydrm;
>> + 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 enabled;
>> + bool cleared;
>> + bool partial;
>> +};
>> +
>> +static inline struct repaper_epd *
>> +epd_from_tinydrm(struct tinydrm_device *tdev)
>> +{
>> + return container_of(tdev, struct repaper_epd, tinydrm);
>> +}
>> +
>> +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 = kmalloc(len, GFP_KERNEL);
>> + if (!txbuf) {
>> + ret = -ENOMEM;
>> + goto out_free;
>> + }
>> + memcpy(txbuf, tx, len);
>> + }
>> +
>> + 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) {
>> + dev_err(&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 void repaper_gray8_to_mono_reversed(u8 *buf, u32 width, u32 height)
>> +{
>> + u8 *gray8 = buf, *mono = buf;
>> + int y, xb, i;
>> +
>> + for (y = 0; y < height; y++)
>> + for (xb = 0; xb < width / 8; xb++) {
>> + u8 byte = 0x00;
>> +
>> + for (i = 0; i < 8; i++) {
>> + int x = xb * 8 + i;
>> +
>> + byte >>= 1;
>> + if (gray8[y * width + x] >> 7)
>> + byte |= BIT(7);
>> + }
>> + *mono++ = byte;
>> + }
>> +}
>> +
>> +static int repaper_fb_dirty(struct drm_framebuffer *fb,
>> + struct drm_file *file_priv,
>> + unsigned int flags, unsigned int color,
>> + struct drm_clip_rect *clips,
>> + unsigned int num_clips)
>> +{
>> + struct tinydrm_device *tdev = fb->dev->dev_private;
>> + struct repaper_epd *epd = epd_from_tinydrm(tdev);
>> + u8 *buf = NULL;
>> + int ret = 0;
>> +
>> + mutex_lock(&tdev->dirty_lock);
>> +
>> + if (!epd->enabled)
>> + goto out_unlock;
>> +
>> + /* fbdev can flush even when we're not interested */
>> + if (tdev->pipe.plane.fb != fb)
>> + goto out_unlock;
>> +
>> + 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, GFP_KERNEL);
>> + if (!buf) {
>> + ret = -ENOMEM;
>> + goto out_unlock;
>> + }
>> +
>> + ret = tinydrm_xrgb8888_to_gray8(buf, fb);
>> + if (ret)
>> + goto out_unlock;
>> +
>> + repaper_gray8_to_mono_reversed(buf, fb->width, fb->height);
>> +
>> + 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_unlock:
>> + mutex_unlock(&tdev->dirty_lock);
>> +
>> + if (ret)
>> + dev_err(fb->dev->dev, "Failed to update display (%d)\n", ret);
>> + kfree(buf);
>> +
>> + return ret;
>> +}
>> +
>> +static const struct drm_framebuffer_funcs repaper_fb_funcs = {
>> + .destroy = drm_fb_cma_destroy,
>> + .create_handle = drm_fb_cma_create_handle,
>> + .dirty = repaper_fb_dirty,
>> +};
>> +
>> +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 void repaper_pipe_enable(struct drm_simple_display_pipe *pipe,
>> + struct drm_crtc_state *crtc_state)
>> +{
>> + struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
>> + struct repaper_epd *epd = epd_from_tinydrm(tdev);
>> + struct spi_device *spi = epd->spi;
>> + struct device *dev = &spi->dev;
>> + bool dc_ok = false;
>> + int i, ret;
>> +
>> + 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) {
>> + dev_err(dev, "timeout waiting for panel to become ready.\n");
>> + power_off(epd);
>> + return;
>> + }
>> +
>> + 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);
>> + return;
>> + }
>> +
>> + /* Disable OE */
>> + repaper_write_val(spi, 0x02, 0x40);
>> +
>> + ret = repaper_read_val(spi, 0x0f);
>> + if (ret < 0 || !(ret & 0x80)) {
>> + if (ret < 0)
>> + dev_err(dev, "failed to read chip (%d)\n", ret);
>> + else
>> + dev_err(dev, "panel is reported broken\n");
>> + power_off(epd);
>> + return;
>> + }
>> +
>> + /* 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) {
>> + dev_err(dev, "failed to read chip (%d)\n", ret);
>> + power_off(epd);
>> + return;
>> + }
>> +
>> + if (ret & 0x40) {
>> + dc_ok = true;
>> + break;
>> + }
>> + }
>> +
>> + if (!dc_ok) {
>> + dev_err(dev, "dc/dc failed\n");
>> + power_off(epd);
>> + return;
>> + }
>> +
>> + /*
>> + * Output enable to disable
>> + * The userspace driver sets this to 0x04, but the datasheet says 0x06
>> + */
>> + repaper_write_val(spi, 0x02, 0x04);
>> +
>> + epd->enabled = true;
>> + epd->partial = false;
>> +}
>> +
>> +static void repaper_pipe_disable(struct drm_simple_display_pipe *pipe)
>> +{
>> + struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
>> + struct repaper_epd *epd = epd_from_tinydrm(tdev);
>> + struct spi_device *spi = epd->spi;
>> + unsigned int line;
>> +
>> + DRM_DEBUG_DRIVER("\n");
>> +
>> + mutex_lock(&tdev->dirty_lock);
>> + epd->enabled = false;
>> + mutex_unlock(&tdev->dirty_lock);
>> +
>> + /* 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 const struct drm_simple_display_pipe_funcs repaper_pipe_funcs = {
>> + .enable = repaper_pipe_enable,
>> + .disable = repaper_pipe_disable,
>> + .update = tinydrm_display_pipe_update,
>> + .prepare_fb = tinydrm_display_pipe_prepare_fb,
>> +};
>> +
>> +static const uint32_t repaper_formats[] = {
>> + DRM_FORMAT_XRGB8888,
>> +};
>> +
>> +static const struct drm_display_mode repaper_e1144cs021_mode = {
>> + TINYDRM_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 = {
>> + TINYDRM_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 = {
>> + TINYDRM_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 = {
>> + TINYDRM_MODE(264, 176, 57, 38),
>> +};
>> +
>> +static const u8 repaper_e2271cs021_cs[] = { 0x00, 0x00, 0x00, 0x7f,
>> + 0xff, 0xfe, 0x00, 0x00 };
>> +
>> +DEFINE_DRM_GEM_CMA_FOPS(repaper_fops);
>> +
>> +static struct drm_driver repaper_driver = {
>> + .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME |
>> + DRIVER_ATOMIC,
>> + .fops = &repaper_fops,
>> + TINYDRM_GEM_DRIVER_OPS,
>> + .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;
>> + const struct of_device_id *match;
>> + struct device *dev = &spi->dev;
>> + struct tinydrm_device *tdev;
>> + enum repaper_model model;
>> + const char *thermal_zone;
>> + struct repaper_epd *epd;
>> + size_t line_buffer_size;
>> + int ret;
>> +
>> + match = of_match_device(repaper_of_match, dev);
>> + if (match) {
>> + model = (enum repaper_model)match->data;
>> + } else {
>> + spi_id = spi_get_device_id(spi);
>> + 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_kzalloc(dev, sizeof(*epd), GFP_KERNEL);
>> + if (!epd)
>> + return -ENOMEM;
>> +
>> + 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)
>> + dev_err(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)
>> + dev_err(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)
>> + dev_err(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)
>> + dev_err(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)) {
>> + dev_err(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)
>> + dev_err(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->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;
>> +
>> + tdev = &epd->tinydrm;
>> +
>> + ret = devm_tinydrm_init(dev, tdev, &repaper_fb_funcs, &repaper_driver);
>> + if (ret)
>> + return ret;
>> +
>> + ret = tinydrm_display_pipe_init(tdev, &repaper_pipe_funcs,
>> + DRM_MODE_CONNECTOR_VIRTUAL,
>> + repaper_formats,
>> + ARRAY_SIZE(repaper_formats), mode, 0);
>> + if (ret)
>> + return ret;
>> +
>> + drm_mode_config_reset(tdev->drm);
>> +
>> + ret = devm_tinydrm_register(tdev);
>> + if (ret)
>> + return ret;
>> +
>> + spi_set_drvdata(spi, tdev);
>> +
>> + DRM_DEBUG_DRIVER("Initialized %s:%s @%uMHz on minor %d\n",
>> + tdev->drm->driver->name, dev_name(dev),
>> + spi->max_speed_hz / 1000000,
>> + tdev->drm->primary->index);
>> +
>> + return 0;
>> +}
>> +
>> +static void repaper_shutdown(struct spi_device *spi)
>> +{
>> + struct tinydrm_device *tdev = spi_get_drvdata(spi);
>> +
>> + tinydrm_shutdown(tdev);
>> +}
>> +
>> +static struct spi_driver repaper_spi_driver = {
>> + .driver = {
>> + .name = "repaper",
>> + .owner = THIS_MODULE,
>> + .of_match_table = repaper_of_match,
>> + },
>> + .id_table = repaper_id,
>> + .probe = repaper_probe,
>> + .shutdown = repaper_shutdown,
>> +};
>> +module_spi_driver(repaper_spi_driver);
>> +
>> +MODULE_DESCRIPTION("Pervasive Displays RePaper DRM driver");
>> +MODULE_AUTHOR("Noralf Trønnes");
>> +MODULE_LICENSE("GPL");
>> --
>> 2.7.4
>>
>> _______________________________________________
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