cpu/stm32: FMC used for low-level LCD parallel interface

boards/stm32f723e-disco/Kconfig

@@ -39,6 +39,7 @@ config BOARD_STM32F723E_DISCO
     select HAVE_FT5X06
     select HAVE_ST7789
     select HAVE_LCD_PARALLEL_16BIT if MODULE_ST7789
+    select HAVE_LCD_PARALLEL_LL_MCU if MODULE_ST7789
 
     select MODULE_PERIPH_UART_HW_FC if HAS_PERIPH_UART_HW_FC && MODULE_PERIPH_UART
     # Workaround due to stdout only working with stdin enabled

boards/stm32f723e-disco/Makefile.dep

@@ -25,6 +25,8 @@ endif
 
 ifneq (,$(filter st7789,$(USEMODULE)))
   USEMODULE += lcd_parallel_16bit
+  USEMODULE += lcd_parallel_ll_mcu
+  FEATURES_REQUIRED += periph_fmc_nor_sram
 endif
 
 # TODO: remove the stdin dependency

boards/stm32f723e-disco/include/periph_conf.h

@@ -42,6 +42,7 @@
 #else
 #include "cfg_usb_otg_fs.h"
 #endif
+#include "lcd_fmc.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -325,6 +326,29 @@ static const fmc_bank_conf_t fmc_bank_config[] = {
                            .bus_turnaround = 3, },  /* 3 HCLKs a 4.63 ns */
         },
     },
+    /* bank 1, subbank 2 is used for LCD with asynchronuous
+     * access in Mode 1, i.e. write timings are not used */
+    {
+        .bank = FMC_BANK_1,
+        .mem_type = FMC_SRAM,
+        .data_width = FMC_BUS_WIDTH_16BIT,
+        .address = 0x64000000,  /* Bank 1, subbank 2 is mapped to 0x64000000 */
+        .size = 4,              /* 1 word for command @ 0x64000000 and
+                                     1 word for data @ 0x64000001 */
+        .nor_sram = {
+            .sub_bank = 2,
+            .ext_mode = false,                      /* Mode 1 used, no separate w_timing */
+                                                    /* timing requirements for ST7789H2:
+                                                       - t_AST min 0 ns (Address setup time)
+                                                       - t_DST min 10 ns (Data setup time)
+                                                       - t_WRL min 15 ns (WE LOW time)
+                                                       - t_WRH min 15 ns (WE HIGH time)
+                                                       - t_WRC min 66 ns (WE cycle time) */
+            .r_timing = {  .addr_setup = 2,         /* t_AST = 10 ns (2 HCLKs a 4.63 ns) */
+                           .data_setup = 8,         /* t_DST = 37 ns (8 HCLKs a 4.63 ns) */
+                           .bus_turnaround = 5, },  /* t_WRH = 23 ns (5 HCLKs a 4.63 ns) */
+        },
+    },
 };
 
 /**
@@ -333,6 +357,25 @@ static const fmc_bank_conf_t fmc_bank_config[] = {
 #define FMC_BANK_NUMOF  ARRAY_SIZE(fmc_bank_config)
 /** @} */
 
+/**
+ * @brief   Descriptors of FMC banks used for LCDs
+ */
+static const lcd_fmc_desc_t lcd_fmc_desc[] = {
+    {
+        .bank = FMC_BANK_CONFIG(1), /* second bank (fmc_bank_config[1]) is used */
+        .cmd_offset = 0x0,          /* address 0x64000000 (offset 0x0) used for commands */
+        .data_offset = 0x2,         /* address 0x64000002 (offset 0x2) used for commands */
+    }
+};
+
+/**
+ * @brief   Number of LCDs using FMC banks
+ *
+ * Because it is used by the preprocessor it has to be a number.
+ * The @ref ARRAY_SIZE can't be used here.
+ */
+#define LCD_FMC_NUMOF  1
+
 #ifdef __cplusplus
 }
 #endif

boards/stm32l496g-disco/Kconfig

@@ -45,6 +45,7 @@ config BOARD_STM32L496G_DISCO
     select HAVE_FT5X06
     select HAVE_ST7789
     select HAVE_LCD_PARALLEL_16BIT if MODULE_ST7789
+    select HAVE_LCD_PARALLEL_LL_MCU if MODULE_ST7789
 
     select MODULE_PERIPH_LPUART if MODULE_PERIPH_UART
     select MODULE_PERIPH_UART_HW_FC if MODULE_PERIPH_UART && !MODULE_PERIPH_SPI_STMOD && HAS_PERIPH_UART_HW_FC

boards/stm32l496g-disco/Makefile.dep

@@ -28,4 +28,6 @@ endif
 
 ifneq (,$(filter st7789,$(USEMODULE)))
   USEMODULE += lcd_parallel_16bit
+  USEMODULE += lcd_parallel_ll_mcu
+  FEATURES_REQUIRED += periph_fmc_nor_sram
 endif

boards/stm32l496g-disco/include/periph_conf.h

@@ -30,6 +30,7 @@
 #include "clk_conf.h"
 #include "cfg_rtt_default.h"
 #include "cfg_usb_otg_fs.h"
+#include "lcd_fmc.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -253,12 +254,55 @@ static const fmc_bank_conf_t fmc_bank_config[] = {
                            .bus_turnaround = 1, },  /* 1 HCLK a 12.5 ns */
         },
     },
+    /* bank 1, subbank 1 is used for LCD with asynchronuous
+     * access in Mode 1, i.e. write timings are not used */
+    {
+        .bank = FMC_BANK_1,
+        .mem_type = FMC_SRAM,
+        .data_width = FMC_BUS_WIDTH_16BIT,
+        .address = 0x60000000,  /* Bank 1, subbank 1 is mapped to 0x60000000 */
+        .size = 2,              /* 1 word for command @ 0x60000000 and
+                                   1 word for data @ 0x60080000 */
+        .nor_sram = {
+            .sub_bank = 1,
+            .ext_mode = false,                      /* Mode 1 used, no separate w_timing */
+                                                    /* timing requirements for ST7789H2:
+                                                       - t_AST min 0 ns (Address setup time)
+                                                       - t_DST min 10 ns (Data setup time)
+                                                       - t_WRL min 15 ns (WE LOW time)
+                                                       - t_WRH min 15 ns (WE HIGH time)
+                                                       - t_WRC min 66 ns (WE cycle time) */
+            .r_timing = {  .addr_setup = 1,         /* t_AST = 12 ns (1 HCLKs a 12.5 ns) */
+                           .data_setup = 3,         /* t_DST = 37 ns (3 HCLKs a 12.5 ns) */
+                           .bus_turnaround = 2, },  /* t_WRH = 25 ns (2 HCLKs a 12.5 ns) */
+        },
+    },
 };
 
 /**
  * @brief   Number of configured FMC banks
  */
 #define FMC_BANK_NUMOF  ARRAY_SIZE(fmc_bank_config)
+
+/**
+ * @brief   Descriptors of FMC banks used for LCDs
+ */
+static const lcd_fmc_desc_t lcd_fmc_desc[] = {
+    {
+        .bank = FMC_BANK_CONFIG(1), /* second bank (fmc_bank_config[1]) is used */
+        .cmd_offset = 0x0,          /* address 0x60000000 (offset 0x00000) used for commands */
+        .data_offset = 0x80000,     /* address 0x60080000 (offset 0x80000) used for data */
+    }
+};
+
+/**
+ * @brief   Number of LCDs using FMC banks
+ *
+ * Because it is used by the preprocessor it has to be a number.
+ * The @ref ARRAY_SIZE can't be used here.
+ */
+#define LCD_FMC_NUMOF  1
+
 /** @} */
 
 /**

cpu/stm32/Kconfig

@@ -78,6 +78,7 @@ rsource "periph/Kconfig.fmc"
 
 if TEST_KCONFIG
 
+rsource "lcd_fmc/Kconfig"
 rsource "periph/Kconfig"
 rsource "stmclk/Kconfig"
 rsource "vectors/Kconfig"

cpu/stm32/Makefile

@@ -6,4 +6,8 @@ ifneq (,$(filter bootloader_stm32,$(USEMODULE)))
   DIRS += bootloader
 endif
 
+ifneq (,$(filter lcd_fmc,$(USEMODULE)))
+  DIRS += lcd_fmc
+endif
+
 include $(RIOTBASE)/Makefile.base

cpu/stm32/Makefile.dep

@@ -54,6 +54,10 @@ ifneq (,$(filter stm32_eth,$(USEMODULE)))
   endif
 endif
 
+ifneq (,$(filter lcd_parallel_ll_mcu,$(USEMODULE)))
+  USEMODULE += lcd_fmc
+endif
+
 ifneq (,$(filter periph_can,$(FEATURES_USED)))
   FEATURES_REQUIRED += periph_gpio
   FEATURES_REQUIRED += periph_gpio_irq

cpu/stm32/include/lcd_fmc.h

@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2023 Gunar Schorcht
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @defgroup    cpu_stm32_lcd_fmc STM32 FMC/FSMC LCD low-level parallel interface driver
+ * @ingroup     cpu_stm32
+ *
+ * @{
+ */
+
+#ifndef LCD_FMC_H
+#define LCD_FMC_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief   Number of LCDs using FMC banks
+ *
+ * It represents the number of elements in LCD FMC bank descriptor array of
+ * type @ref lcd_fmc_desc_t. Because it is used by the preprocessor, it has
+ * to be defined as a number. It is not possible to use the @ref ARRAY_SIZE
+ * macro here.
+ *
+ * @note `LCD_FMC_NUMOF` has to be equal to the number of elements in the
+ *       LCD FMC bank descriptor array of type @ref lcd_fmc_desc_t.
+ */
+#if DOXYGEN
+#define LCD_FMC_NUMOF  1
+#endif
+
+/**
+ * @brief   Descriptor of the FMC bank used for a LCD
+ *
+ * The board definition has to specify the array @ref lcd_fmc_desc of type
+ * @ref lcd_fmc_desc_t which defines the FMC banks and the address offsets used
+ * for the LCD displays that are connected to FMC banks.
+ *
+ * @note In the case that multiple LCDs are connected to FMC banks, the FMC
+ *       bank descriptors for LCDs of type @ref lcd_fmc_desc_t
+ *       must be defined in same order as the LCD devices.
+ */
+typedef struct {
+    const fmc_bank_conf_t *bank;    /**< FMC bank config used for the LCD */
+    uint32_t cmd_offset;            /**< offset to the bank address used for commands */
+    uint32_t data_offset;           /**< offset to the bank address used for data */
+} lcd_fmc_desc_t;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* LCD_FMC_H */
+/** @} */

cpu/stm32/include/periph/cpu_fmc.h

@@ -64,6 +64,17 @@
 extern "C" {
 #endif
 
+/**
+ * @brief   Gives the configuration of n-th bank
+ *
+ * This macro gives a pointer to the n-th entry of type @ref fmc_bank_conf_t of
+ * the banks configured by the board in the @ref fmc_bank_config array. n is in
+ * the range 0 ... @ref FMC_BANK_NUMOF - 1.
+ */
+#ifndef FMC_BANK_CONFIG
+#define FMC_BANK_CONFIG(n)  (&fmc_bank_config[n])
+#endif
+
 /**
  * @brief   Number of data pins used
  *
@@ -257,7 +268,7 @@
  *
  * The GPIOs are defined depending on used memory type according to the
  * FMC pin definition in Table 12 of section 4 in the
  * [Datasheet for STM32F765xx, STM32F767xx, STM32F768Ax, STM32F769xx](https://www.st.com/resource/en/datasheet/stm32f767zi.pdf).
  * Which memory types are used is defined by the pseudomodules
  * `periph_fmc_nor_sram`, `periph_fmc_nand` and `periph_fmc_sdram`
  *

cpu/stm32/lcd_fmc/Kconfig

@@ -0,0 +1,13 @@
+# Copyright (c) 2023 Gunar Schorcht
+#
+# This file is subject to the terms and conditions of the GNU Lesser
+# General Public License v2.1. See the file LICENSE in the top level
+# directory for more details.
+#
+
+config MODULE_LCD_FMC
+    bool
+    depends on MODULE_LCD
+    select MODULE_PERIPH_FMC
+    select MODULE_PERIPH_FMC_NOR_SRAM
+    default y if HAVE_LCD_PARALLEL_LL_MCU

cpu/stm32/lcd_fmc/Makefile

@@ -0,0 +1,3 @@
+MODULE = lcd_fmc
+
+include $(RIOTBASE)/Makefile.base