drivers: flash: rpi_pico: add support for rp2350 flash controller

The Raspberry Pi Pico 2 uses a QMI flash controller, which differs from the
SSI controller used in the original Pico. Zephyr already has support for
the SSI controller, but lacked support for QMI.

This change adds the QMI flash controller implementation in the
flash_rpi_pico.c driver file. Additionally, the RP2350 SoC devicetree file
(rp2350.dtsi) has been updated to enable and describe the flash controller
for Pico 2.

Signed-off-by: Hanan Arshad <[email protected]>

Author: hanan619

boards/raspberrypi/rpi_pico2/rpi_pico2.dtsi

@@ -16,6 +16,7 @@
 	chosen {
 		zephyr,sram = &sram0;
 		zephyr,flash = &flash0;
+		zephyr,flash-controller = &qmi;
 		zephyr,console = &uart0;
 		zephyr,shell-uart = &uart0;
 		zephyr,code-partition = &code_partition;

drivers/flash/flash_rpi_pico.c

@@ -13,15 +13,8 @@
 #include <zephyr/drivers/flash.h>
 #include <zephyr/logging/log.h>
 #include <zephyr/irq.h>
-#include <zephyr/toolchain.h>
 
 #include <hardware/flash.h>
-#include <hardware/regs/io_qspi.h>
-#include <hardware/regs/pads_qspi.h>
-#include <hardware/structs/ssi.h>
-#include <hardware/structs/xip_ctrl.h>
-#include <hardware/resets.h>
-#include <pico/bootrom.h>
 
 LOG_MODULE_REGISTER(flash_rpi_pico, CONFIG_FLASH_LOG_LEVEL);
 
@@ -31,162 +24,14 @@ LOG_MODULE_REGISTER(flash_rpi_pico, CONFIG_FLASH_LOG_LEVEL);
 #define SECTOR_SIZE DT_PROP(DT_CHOSEN(zephyr_flash), erase_block_size)
 #define ERASE_VALUE 0xff
 #define FLASH_SIZE KB(CONFIG_FLASH_SIZE)
-#define FLASH_BASE CONFIG_FLASH_BASE_ADDRESS
-#define SSI_BASE_ADDRESS DT_REG_ADDR(DT_CHOSEN(zephyr_flash_controller))
 
 static const struct flash_parameters flash_rpi_parameters = {
 	.write_block_size = 1,
 	.erase_value = ERASE_VALUE,
 };
 
-/**
- * Low level flash functions are based on:
- * github.com/raspberrypi/pico-bootrom/blob/master/bootrom/program_flash_generic.c
- * and
- * github.com/raspberrypi/pico-sdk/blob/master/src/rp2_common/hardware_flash/flash.c
- */
-
-#define FLASHCMD_PAGE_PROGRAM 0x02
-#define FLASHCMD_READ_STATUS 0x05
-#define FLASHCMD_WRITE_ENABLE 0x06
-#define BOOT2_SIZE_WORDS 64
-
-enum outover {
-	OUTOVER_NORMAL = 0,
-	OUTOVER_INVERT,
-	OUTOVER_LOW,
-	OUTOVER_HIGH
-};
-
-static ssi_hw_t *const ssi = (ssi_hw_t *)SSI_BASE_ADDRESS;
-static uint32_t boot2_copyout[BOOT2_SIZE_WORDS];
-static bool boot2_copyout_valid;
 static uint8_t flash_ram_buffer[PAGE_SIZE];
 
-static void __no_inline_not_in_flash_func(flash_init_boot2_copyout)(void)
-{
-	if (boot2_copyout_valid) {
-		return;
-	}
-	for (int i = 0; i < BOOT2_SIZE_WORDS; ++i) {
-		boot2_copyout[i] = ((uint32_t *)FLASH_BASE)[i];
-	}
-	__compiler_memory_barrier();
-	boot2_copyout_valid = true;
-}
-
-static void __no_inline_not_in_flash_func(flash_enable_xip_via_boot2)(void)
-{
-	((void (*)(void))((uint32_t)boot2_copyout+1))();
-}
-
-void __no_inline_not_in_flash_func(flash_cs_force)(enum outover over)
-{
-	io_rw_32 *reg = (io_rw_32 *) (IO_QSPI_BASE + IO_QSPI_GPIO_QSPI_SS_CTRL_OFFSET);
-	*reg = (*reg & ~IO_QSPI_GPIO_QSPI_SS_CTRL_OUTOVER_BITS)
-		| (over << IO_QSPI_GPIO_QSPI_SS_CTRL_OUTOVER_LSB);
-	(void) *reg;
-}
-
-int __no_inline_not_in_flash_func(flash_was_aborted)()
-{
-	return *(io_rw_32 *) (IO_QSPI_BASE + IO_QSPI_GPIO_QSPI_SD1_CTRL_OFFSET)
-		   & IO_QSPI_GPIO_QSPI_SD1_CTRL_INOVER_BITS;
-}
-
-void __no_inline_not_in_flash_func(flash_put_get)(const uint8_t *tx, uint8_t *rx, size_t count,
-						size_t rx_skip)
-{
-	const uint max_in_flight = 16 - 2;
-	size_t tx_count = count;
-	size_t rx_count = count;
-	bool did_something;
-	uint32_t tx_level;
-	uint32_t rx_level;
-	uint8_t rxbyte;
-
-	while (tx_count || rx_skip || rx_count) {
-		tx_level = ssi_hw->txflr;
-		rx_level = ssi_hw->rxflr;
-		did_something = false;
-		if (tx_count && tx_level + rx_level < max_in_flight) {
-			ssi->dr0 = (uint32_t) (tx ? *tx++ : 0);
-			--tx_count;
-			did_something = true;
-		}
-		if (rx_level) {
-			rxbyte = ssi->dr0;
-			did_something = true;
-			if (rx_skip) {
-				--rx_skip;
-			} else {
-				if (rx) {
-					*rx++ = rxbyte;
-				}
-				--rx_count;
-			}
-		}
-
-		if (!did_something && __builtin_expect(flash_was_aborted(), 0)) {
-			break;
-		}
-	}
-	flash_cs_force(OUTOVER_HIGH);
-}
-
-void __no_inline_not_in_flash_func(flash_put_get_wrapper)(uint8_t cmd, const uint8_t *tx,
-					uint8_t *rx, size_t count)
-{
-	flash_cs_force(OUTOVER_LOW);
-	ssi->dr0 = cmd;
-	flash_put_get(tx, rx, count, 1);
-}
-
-static ALWAYS_INLINE void flash_put_cmd_addr(uint8_t cmd, uint32_t addr)
-{
-	flash_cs_force(OUTOVER_LOW);
-	addr |= cmd << 24;
-	for (int i = 0; i < 4; ++i) {
-		ssi->dr0 = addr >> 24;
-		addr <<= 8;
-	}
-}
-
-void __no_inline_not_in_flash_func(flash_write_partial_internal)(uint32_t addr, const uint8_t *data,
-					size_t size)
-{
-	uint8_t status_reg;
-
-	flash_put_get_wrapper(FLASHCMD_WRITE_ENABLE, NULL, NULL, 0);
-	flash_put_cmd_addr(FLASHCMD_PAGE_PROGRAM, addr);
-	flash_put_get(data, NULL, size, 4);
-
-	do {
-		flash_put_get_wrapper(FLASHCMD_READ_STATUS, NULL, &status_reg, 1);
-	} while (status_reg & 0x1 && !flash_was_aborted());
-}
-
-void __no_inline_not_in_flash_func(flash_write_partial)(uint32_t flash_offs, const uint8_t *data,
-							size_t count)
-{
-	rom_connect_internal_flash_fn connect_internal_flash = (rom_connect_internal_flash_fn)
-					rom_func_lookup_inline(ROM_FUNC_CONNECT_INTERNAL_FLASH);
-	rom_flash_exit_xip_fn exit_xip = (rom_flash_exit_xip_fn)
-						rom_func_lookup_inline(ROM_FUNC_FLASH_EXIT_XIP);
-	rom_flash_flush_cache_fn flush_cache = (rom_flash_flush_cache_fn)
-						rom_func_lookup_inline(ROM_FUNC_FLASH_FLUSH_CACHE);
-
-	flash_init_boot2_copyout();
-
-	__compiler_memory_barrier();
-
-	connect_internal_flash();
-	exit_xip();
-	flash_write_partial_internal(flash_offs, data, count);
-	flush_cache();
-	flash_enable_xip_via_boot2();
-}
-
 static bool is_valid_range(off_t offset, uint32_t size)
 {
 	return (offset >= 0) && ((offset + size) <= FLASH_SIZE);

dts/arm/raspberrypi/rpi_pico/rp2350.dtsi

@@ -192,7 +192,7 @@
 
 		qmi: flash-controller@400d0000 {
 			compatible = "raspberrypi,pico-flash-controller";
-			reg = <0x400d0000 0xfc>;
+			reg = <0x400d0000 0x54>;
 
 			#address-cells = <1>;
 			#size-cells = <1>;
@@ -202,7 +202,6 @@
 				write-block-size = <1>;
 				erase-block-size = <DT_SIZE_K(4)>;
 			};
-			status = "disabled";
 		};
 
 		reset: reset-controller@40020000 {