altos: Add ST7565 LCD driver

[fw/altos] / src / drivers / ao_st7565.c

diff --git a/src/drivers/ao_st7565.c b/src/drivers/ao_st7565.c
new file mode 100644 (file)
index 0000000..e45db4d
--- /dev/null
+++ b/src/drivers/ao_st7565.c
@@ -0,0 +1,158 @@
+/*
+ * Copyright © 2023 Keith Packard <keithp@keithp.com>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include <ao.h>
+#include <ao_st7565.h>
+
+static void
+ao_st7565_reset(void)
+{
+       ao_gpio_set(AO_ST7565_RESET_PORT, AO_ST7565_RESET_PIN, 0);
+       ao_delay(AO_MS_TO_TICKS(100));
+       ao_gpio_set(AO_ST7565_RESET_PORT, AO_ST7565_RESET_PIN, 1);
+       ao_delay(AO_MS_TO_TICKS(100));
+}
+
+
+static void
+ao_st7565_start(uint8_t a0)
+{
+       ao_gpio_set(AO_ST7565_A0_PORT, AO_ST7565_A0_PIN, a0);
+       ao_spi_get_bit(AO_ST7565_CS_PORT,
+                      AO_ST7565_CS_PIN,
+                      AO_ST7565_SPI_BUS,
+                      AO_ST7565_SPI_SPEED);
+}
+
+static void
+ao_st7565_stop(void)
+{
+       ao_spi_put_bit(AO_ST7565_CS_PORT,
+                      AO_ST7565_CS_PIN,
+                      AO_ST7565_SPI_BUS);
+       ao_gpio_set(AO_ST7565_A0_PORT, AO_ST7565_A0_PIN, 1);
+}
+
+
+static void
+ao_st7565_instruction(uint8_t cmd)
+{
+       ao_st7565_start(0);
+       ao_spi_send(&cmd, 1, AO_ST7565_SPI_BUS);
+       ao_st7565_stop();
+}
+
+static void
+ao_st7565_instruction_param(uint8_t cmd, uint8_t param)
+{
+       uint8_t b[2] = { cmd, param };
+       ao_st7565_start(0);
+       ao_spi_send(b, 2, AO_ST7565_SPI_BUS);
+       ao_st7565_stop();
+}
+
+static void
+ao_st7565_instructions(uint8_t *cmd, uint16_t len)
+{
+       ao_st7565_start(0);
+       ao_spi_send(cmd, len, AO_ST7565_SPI_BUS);
+       ao_st7565_stop();
+}
+
+static void
+ao_st7565_data(const void *base, uint16_t len)
+{
+       ao_st7565_start(1);
+       ao_spi_send(base, len, AO_ST7565_SPI_BUS);
+       ao_st7565_stop();
+}
+
+static void
+ao_st7565_set_brightness(uint8_t val)
+{
+       ao_st7565_instruction_param(AO_ST7565_ELECTRONIC_VOLUME_SET, val);
+}
+
+static bool setup_done;
+
+static void
+ao_st7565_setup(void)
+{
+       if (setup_done)
+               return;
+       setup_done = true;
+       ao_st7565_reset();
+       ao_st7565_instruction(AO_ST7565_BIAS);
+       ao_st7565_instruction(AO_ST7565_ADC_SELECT_NORMAL);
+
+       ao_st7565_instruction(AO_ST7565_COMMON_MODE_NORMAL);
+       ao_st7565_instruction(AO_ST7565_DISPLAY_START_LINE_SET(0));
+       ao_st7565_instruction(AO_ST7565_POWER_CONTROL_SET(0x4));
+       ao_delay(AO_MS_TO_TICKS(50));
+       ao_st7565_instruction(AO_ST7565_POWER_CONTROL_SET(0x6));
+       ao_delay(AO_MS_TO_TICKS(50));
+       ao_st7565_instruction(AO_ST7565_POWER_CONTROL_SET(0x7));
+       ao_delay(AO_MS_TO_TICKS(10));
+       ao_st7565_instruction(AO_ST7565_RESISTOR_RATIO_SET(5));
+       ao_st7565_instruction(AO_ST7565_DISPLAY_ON);
+       ao_st7565_set_brightness(0x10);
+}
+
+static uint8_t rotbuf[AO_ST7565_WIDTH];
+
+void
+ao_st7565_update(struct ao_bitmap *bitmap)
+{
+       uint8_t         col, c, page;
+       int             row;
+       uint32_t        *line;
+       uint8_t         *r;
+
+       ao_st7565_setup();
+
+       line = bitmap->base;
+       for (page = 0; page < 8; page++) {
+               uint8_t         i[4] = {
+                       AO_ST7565_PAGE_ADDRESS_SET(7-page),
+                       AO_ST7565_COLUMN_ADDRESS_SET_MSN(0 >> 4),
+                       AO_ST7565_COLUMN_ADDRESS_SET_MSN(0 & 0xf),
+                       AO_ST7565_RMW
+               };
+               memset(rotbuf, 0, sizeof(rotbuf));
+               for (row = 7; row >= 0; row--) {
+                       r = rotbuf;
+                       for (col = 0; col < AO_BITMAP_STRIDE(AO_ST7565_WIDTH); col++) {
+                               uint32_t        bits = ~*line++;
+                               for (c = 0; c < 32; c++) {
+                                       *r++ |= ((bits >> c) & 1) << row;
+                               }
+                       }
+               }
+               ao_st7565_instructions(i, 4);
+               ao_st7565_data(rotbuf, AO_ST7565_WIDTH);
+       }
+}
+
+void
+ao_st7565_init(void)
+{
+       ao_enable_output(AO_ST7565_RESET_PORT, AO_ST7565_RESET_PIN, 1);
+       ao_enable_output(AO_ST7565_A0_PORT, AO_ST7565_A0_PIN, 1);
+
+       ao_enable_cs(AO_ST7565_CS_PORT, AO_ST7565_CS_PIN);
+}