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path: root/drivers/staging/fbtft/fbtft-bus.c
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Diffstat (limited to 'drivers/staging/fbtft/fbtft-bus.c')
-rw-r--r--drivers/staging/fbtft/fbtft-bus.c256
1 files changed, 256 insertions, 0 deletions
diff --git a/drivers/staging/fbtft/fbtft-bus.c b/drivers/staging/fbtft/fbtft-bus.c
new file mode 100644
index 000000000000..b3cddb0b3d69
--- /dev/null
+++ b/drivers/staging/fbtft/fbtft-bus.c
@@ -0,0 +1,256 @@
+#include <linux/export.h>
+#include <linux/errno.h>
+#include <linux/gpio.h>
+#include <linux/spi/spi.h>
+#include "fbtft.h"
+
+
+
+
+/*****************************************************************************
+ *
+ * void (*write_reg)(struct fbtft_par *par, int len, ...);
+ *
+ *****************************************************************************/
+
+#define define_fbtft_write_reg(func, type, modifier) \
+void func(struct fbtft_par *par, int len, ...) \
+{ \
+ va_list args; \
+ int i, ret; \
+ int offset = 0; \
+ type *buf = (type *)par->buf; \
+ \
+ if (unlikely(par->debug & DEBUG_WRITE_REGISTER)) { \
+ va_start(args, len); \
+ for (i = 0; i < len; i++) { \
+ buf[i] = (type)va_arg(args, unsigned int); \
+ } \
+ va_end(args); \
+ fbtft_par_dbg_hex(DEBUG_WRITE_REGISTER, par, par->info->device, type, buf, len, "%s: ", __func__); \
+ } \
+ \
+ va_start(args, len); \
+ \
+ if (par->startbyte) { \
+ *(u8 *)par->buf = par->startbyte; \
+ buf = (type *)(par->buf + 1); \
+ offset = 1; \
+ } \
+ \
+ *buf = modifier((type)va_arg(args, unsigned int)); \
+ if (par->gpio.dc != -1) \
+ gpio_set_value(par->gpio.dc, 0); \
+ ret = par->fbtftops.write(par, par->buf, sizeof(type)+offset); \
+ if (ret < 0) { \
+ va_end(args); \
+ dev_err(par->info->device, "%s: write() failed and returned %d\n", __func__, ret); \
+ return; \
+ } \
+ len--; \
+ \
+ if (par->startbyte) \
+ *(u8 *)par->buf = par->startbyte | 0x2; \
+ \
+ if (len) { \
+ i = len; \
+ while (i--) { \
+ *buf++ = modifier((type)va_arg(args, unsigned int)); \
+ } \
+ if (par->gpio.dc != -1) \
+ gpio_set_value(par->gpio.dc, 1); \
+ ret = par->fbtftops.write(par, par->buf, len * (sizeof(type)+offset)); \
+ if (ret < 0) { \
+ va_end(args); \
+ dev_err(par->info->device, "%s: write() failed and returned %d\n", __func__, ret); \
+ return; \
+ } \
+ } \
+ va_end(args); \
+} \
+EXPORT_SYMBOL(func);
+
+define_fbtft_write_reg(fbtft_write_reg8_bus8, u8, )
+define_fbtft_write_reg(fbtft_write_reg16_bus8, u16, cpu_to_be16)
+define_fbtft_write_reg(fbtft_write_reg16_bus16, u16, )
+
+void fbtft_write_reg8_bus9(struct fbtft_par *par, int len, ...)
+{
+ va_list args;
+ int i, ret;
+ int pad = 0;
+ u16 *buf = (u16 *)par->buf;
+
+ if (unlikely(par->debug & DEBUG_WRITE_REGISTER)) {
+ va_start(args, len);
+ for (i = 0; i < len; i++)
+ *(((u8 *)buf) + i) = (u8)va_arg(args, unsigned int);
+ va_end(args);
+ fbtft_par_dbg_hex(DEBUG_WRITE_REGISTER, par,
+ par->info->device, u8, buf, len, "%s: ", __func__);
+ }
+ if (len <= 0)
+ return;
+
+ if (par->spi && (par->spi->bits_per_word == 8)) {
+ /* we're emulating 9-bit, pad start of buffer with no-ops
+ (assuming here that zero is a no-op) */
+ pad = (len % 4) ? 4 - (len % 4) : 0;
+ for (i = 0; i < pad; i++)
+ *buf++ = 0x000;
+ }
+
+ va_start(args, len);
+ *buf++ = (u8)va_arg(args, unsigned int);
+ i = len - 1;
+ while (i--) {
+ *buf = (u8)va_arg(args, unsigned int);
+ *buf++ |= 0x100; /* dc=1 */
+ }
+ va_end(args);
+ ret = par->fbtftops.write(par, par->buf, (len + pad) * sizeof(u16));
+ if (ret < 0) {
+ dev_err(par->info->device,
+ "%s: write() failed and returned %d\n", __func__, ret);
+ return;
+ }
+}
+EXPORT_SYMBOL(fbtft_write_reg8_bus9);
+
+
+
+
+/*****************************************************************************
+ *
+ * int (*write_vmem)(struct fbtft_par *par);
+ *
+ *****************************************************************************/
+
+/* 16 bit pixel over 8-bit databus */
+int fbtft_write_vmem16_bus8(struct fbtft_par *par, size_t offset, size_t len)
+{
+ u16 *vmem16;
+ u16 *txbuf16 = (u16 *)par->txbuf.buf;
+ size_t remain;
+ size_t to_copy;
+ size_t tx_array_size;
+ int i;
+ int ret = 0;
+ size_t startbyte_size = 0;
+
+ fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s(offset=%zu, len=%zu)\n",
+ __func__, offset, len);
+
+ remain = len / 2;
+ vmem16 = (u16 *)(par->info->screen_base + offset);
+
+ if (par->gpio.dc != -1)
+ gpio_set_value(par->gpio.dc, 1);
+
+ /* non buffered write */
+ if (!par->txbuf.buf)
+ return par->fbtftops.write(par, vmem16, len);
+
+ /* buffered write */
+ tx_array_size = par->txbuf.len / 2;
+
+ if (par->startbyte) {
+ txbuf16 = (u16 *)(par->txbuf.buf + 1);
+ tx_array_size -= 2;
+ *(u8 *)(par->txbuf.buf) = par->startbyte | 0x2;
+ startbyte_size = 1;
+ }
+
+ while (remain) {
+ to_copy = remain > tx_array_size ? tx_array_size : remain;
+ dev_dbg(par->info->device, " to_copy=%zu, remain=%zu\n",
+ to_copy, remain - to_copy);
+
+ for (i = 0; i < to_copy; i++)
+ txbuf16[i] = cpu_to_be16(vmem16[i]);
+
+ vmem16 = vmem16 + to_copy;
+ ret = par->fbtftops.write(par, par->txbuf.buf,
+ startbyte_size + to_copy * 2);
+ if (ret < 0)
+ return ret;
+ remain -= to_copy;
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL(fbtft_write_vmem16_bus8);
+
+/* 16 bit pixel over 9-bit SPI bus: dc + high byte, dc + low byte */
+int fbtft_write_vmem16_bus9(struct fbtft_par *par, size_t offset, size_t len)
+{
+ u8 *vmem8;
+ u16 *txbuf16 = par->txbuf.buf;
+ size_t remain;
+ size_t to_copy;
+ size_t tx_array_size;
+ int i;
+ int ret = 0;
+
+ fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s(offset=%zu, len=%zu)\n",
+ __func__, offset, len);
+
+ if (!par->txbuf.buf) {
+ dev_err(par->info->device, "%s: txbuf.buf is NULL\n", __func__);
+ return -1;
+ }
+
+ remain = len;
+ vmem8 = par->info->screen_base + offset;
+
+ tx_array_size = par->txbuf.len / 2;
+
+ while (remain) {
+ to_copy = remain > tx_array_size ? tx_array_size : remain;
+ dev_dbg(par->info->device, " to_copy=%zu, remain=%zu\n",
+ to_copy, remain - to_copy);
+
+#ifdef __LITTLE_ENDIAN
+ for (i = 0; i < to_copy; i += 2) {
+ txbuf16[i] = 0x0100 | vmem8[i+1];
+ txbuf16[i+1] = 0x0100 | vmem8[i];
+ }
+#else
+ for (i = 0; i < to_copy; i++)
+ txbuf16[i] = 0x0100 | vmem8[i];
+#endif
+ vmem8 = vmem8 + to_copy;
+ ret = par->fbtftops.write(par, par->txbuf.buf, to_copy*2);
+ if (ret < 0)
+ return ret;
+ remain -= to_copy;
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL(fbtft_write_vmem16_bus9);
+
+int fbtft_write_vmem8_bus8(struct fbtft_par *par, size_t offset, size_t len)
+{
+ dev_err(par->info->device, "%s: function not implemented\n", __func__);
+ return -1;
+}
+EXPORT_SYMBOL(fbtft_write_vmem8_bus8);
+
+/* 16 bit pixel over 16-bit databus */
+int fbtft_write_vmem16_bus16(struct fbtft_par *par, size_t offset, size_t len)
+{
+ u16 *vmem16;
+
+ fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s(offset=%zu, len=%zu)\n",
+ __func__, offset, len);
+
+ vmem16 = (u16 *)(par->info->screen_base + offset);
+
+ if (par->gpio.dc != -1)
+ gpio_set_value(par->gpio.dc, 1);
+
+ /* no need for buffered write with 16-bit bus */
+ return par->fbtftops.write(par, vmem16, len);
+}
+EXPORT_SYMBOL(fbtft_write_vmem16_bus16);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.