--- /dev/null
+#include <linux/export.h>
+#include <linux/errno.h>
+#include <linux/gpio.h>
+#include <linux/spi/spi.h>
+#include "fbtft.h"
+
+int fbtft_write_spi(struct fbtft_par *par, void *buf, size_t len)
+{
+ struct spi_transfer t = {
+ .tx_buf = buf,
+ .len = len,
+ };
+ struct spi_message m;
+
+ fbtft_par_dbg_hex(DEBUG_WRITE, par, par->info->device, u8, buf, len,
+ "%s(len=%d): ", __func__, len);
+
+ if (!par->spi) {
+ dev_err(par->info->device,
+ "%s: par->spi is unexpectedly NULL\n", __func__);
+ return -1;
+ }
+
+ spi_message_init(&m);
+ if (par->txbuf.dma && buf == par->txbuf.buf) {
+ t.tx_dma = par->txbuf.dma;
+ m.is_dma_mapped = 1;
+ }
+ spi_message_add_tail(&t, &m);
+ return spi_sync(par->spi, &m);
+}
+EXPORT_SYMBOL(fbtft_write_spi);
+
+/**
+ * fbtft_write_spi_emulate_9() - write SPI emulating 9-bit
+ * @par: Driver data
+ * @buf: Buffer to write
+ * @len: Length of buffer (must be divisible by 8)
+ *
+ * When 9-bit SPI is not available, this function can be used to emulate that.
+ * par->extra must hold a transformation buffer used for transfer.
+ */
+int fbtft_write_spi_emulate_9(struct fbtft_par *par, void *buf, size_t len)
+{
+ u16 *src = buf;
+ u8 *dst = par->extra;
+ size_t size = len / 2;
+ size_t added = 0;
+ int bits, i, j;
+ u64 val, dc, tmp;
+
+ fbtft_par_dbg_hex(DEBUG_WRITE, par, par->info->device, u8, buf, len,
+ "%s(len=%d): ", __func__, len);
+
+ if (!par->extra) {
+ dev_err(par->info->device, "%s: error: par->extra is NULL\n",
+ __func__);
+ return -EINVAL;
+ }
+ if ((len % 8) != 0) {
+ dev_err(par->info->device,
+ "error: len=%zu must be divisible by 8\n", len);
+ return -EINVAL;
+ }
+
+ for (i = 0; i < size; i += 8) {
+ tmp = 0;
+ bits = 63;
+ for (j = 0; j < 7; j++) {
+ dc = (*src & 0x0100) ? 1 : 0;
+ val = *src & 0x00FF;
+ tmp |= dc << bits;
+ bits -= 8;
+ tmp |= val << bits--;
+ src++;
+ }
+ tmp |= ((*src & 0x0100) ? 1 : 0);
+ *(u64 *)dst = cpu_to_be64(tmp);
+ dst += 8;
+ *dst++ = (u8)(*src++ & 0x00FF);
+ added++;
+ }
+
+ return spi_write(par->spi, par->extra, size + added);
+}
+EXPORT_SYMBOL(fbtft_write_spi_emulate_9);
+
+int fbtft_read_spi(struct fbtft_par *par, void *buf, size_t len)
+{
+ int ret;
+ u8 txbuf[32] = { 0, };
+ struct spi_transfer t = {
+ .speed_hz = 2000000,
+ .rx_buf = buf,
+ .len = len,
+ };
+ struct spi_message m;
+
+ if (!par->spi) {
+ dev_err(par->info->device,
+ "%s: par->spi is unexpectedly NULL\n", __func__);
+ return -ENODEV;
+ }
+
+ if (par->startbyte) {
+ if (len > 32) {
+ dev_err(par->info->device,
+ "len=%zu can't be larger than 32 when using 'startbyte'\n",
+ len);
+ return -EINVAL;
+ }
+ txbuf[0] = par->startbyte | 0x3;
+ t.tx_buf = txbuf;
+ fbtft_par_dbg_hex(DEBUG_READ, par, par->info->device, u8,
+ txbuf, len, "%s(len=%d) txbuf => ", __func__, len);
+ }
+
+ spi_message_init(&m);
+ spi_message_add_tail(&t, &m);
+ ret = spi_sync(par->spi, &m);
+ fbtft_par_dbg_hex(DEBUG_READ, par, par->info->device, u8, buf, len,
+ "%s(len=%d) buf <= ", __func__, len);
+
+ return ret;
+}
+EXPORT_SYMBOL(fbtft_read_spi);
+
+/*
+ * Optimized use of gpiolib is twice as fast as no optimization
+ * only one driver can use the optimized version at a time
+ */
+int fbtft_write_gpio8_wr(struct fbtft_par *par, void *buf, size_t len)
+{
+ u8 data;
+ int i;
+#ifndef DO_NOT_OPTIMIZE_FBTFT_WRITE_GPIO
+ static u8 prev_data;
+#endif
+
+ fbtft_par_dbg_hex(DEBUG_WRITE, par, par->info->device, u8, buf, len,
+ "%s(len=%d): ", __func__, len);
+
+ while (len--) {
+ data = *(u8 *) buf;
+
+ /* Start writing by pulling down /WR */
+ gpio_set_value(par->gpio.wr, 0);
+
+ /* Set data */
+#ifndef DO_NOT_OPTIMIZE_FBTFT_WRITE_GPIO
+ if (data == prev_data) {
+ gpio_set_value(par->gpio.wr, 0); /* used as delay */
+ } else {
+ for (i = 0; i < 8; i++) {
+ if ((data & 1) != (prev_data & 1))
+ gpio_set_value(par->gpio.db[i],
+ data & 1);
+ data >>= 1;
+ prev_data >>= 1;
+ }
+ }
+#else
+ for (i = 0; i < 8; i++) {
+ gpio_set_value(par->gpio.db[i], data & 1);
+ data >>= 1;
+ }
+#endif
+
+ /* Pullup /WR */
+ gpio_set_value(par->gpio.wr, 1);
+
+#ifndef DO_NOT_OPTIMIZE_FBTFT_WRITE_GPIO
+ prev_data = *(u8 *) buf;
+#endif
+ buf++;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(fbtft_write_gpio8_wr);
+
+int fbtft_write_gpio16_wr(struct fbtft_par *par, void *buf, size_t len)
+{
+ u16 data;
+ int i;
+#ifndef DO_NOT_OPTIMIZE_FBTFT_WRITE_GPIO
+ static u16 prev_data;
+#endif
+
+ fbtft_par_dbg_hex(DEBUG_WRITE, par, par->info->device, u8, buf, len,
+ "%s(len=%d): ", __func__, len);
+
+ while (len) {
+ data = *(u16 *) buf;
+
+ /* Start writing by pulling down /WR */
+ gpio_set_value(par->gpio.wr, 0);
+
+ /* Set data */
+#ifndef DO_NOT_OPTIMIZE_FBTFT_WRITE_GPIO
+ if (data == prev_data) {
+ gpio_set_value(par->gpio.wr, 0); /* used as delay */
+ } else {
+ for (i = 0; i < 16; i++) {
+ if ((data & 1) != (prev_data & 1))
+ gpio_set_value(par->gpio.db[i],
+ data & 1);
+ data >>= 1;
+ prev_data >>= 1;
+ }
+ }
+#else
+ for (i = 0; i < 16; i++) {
+ gpio_set_value(par->gpio.db[i], data & 1);
+ data >>= 1;
+ }
+#endif
+
+ /* Pullup /WR */
+ gpio_set_value(par->gpio.wr, 1);
+
+#ifndef DO_NOT_OPTIMIZE_FBTFT_WRITE_GPIO
+ prev_data = *(u16 *) buf;
+#endif
+ buf += 2;
+ len -= 2;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(fbtft_write_gpio16_wr);
+
+int fbtft_write_gpio16_wr_latched(struct fbtft_par *par, void *buf, size_t len)
+{
+ dev_err(par->info->device, "%s: function not implemented\n", __func__);
+ return -1;
+}
+EXPORT_SYMBOL(fbtft_write_gpio16_wr_latched);
Code Review / kvmfornfv.git / blobdiff