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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c')
-rw-r--r-- | arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c | 324 |
1 files changed, 324 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c b/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c new file mode 100644 index 000000000..e02bdabf3 --- /dev/null +++ b/arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c @@ -0,0 +1,324 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c + * + * udbg serial input/output routines for the USB Gecko adapter. + * Copyright (C) 2008-2009 The GameCube Linux Team + * Copyright (C) 2008,2009 Albert Herranz + */ + +#include <linux/of_address.h> + +#include <mm/mmu_decl.h> + +#include <asm/io.h> +#include <asm/udbg.h> +#include <asm/fixmap.h> + +#include "usbgecko_udbg.h" + + +#define EXI_CLK_32MHZ 5 + +#define EXI_CSR 0x00 +#define EXI_CSR_CLKMASK (0x7<<4) +#define EXI_CSR_CLK_32MHZ (EXI_CLK_32MHZ<<4) +#define EXI_CSR_CSMASK (0x7<<7) +#define EXI_CSR_CS_0 (0x1<<7) /* Chip Select 001 */ + +#define EXI_CR 0x0c +#define EXI_CR_TSTART (1<<0) +#define EXI_CR_WRITE (1<<2) +#define EXI_CR_READ_WRITE (2<<2) +#define EXI_CR_TLEN(len) (((len)-1)<<4) + +#define EXI_DATA 0x10 + +#define UG_READ_ATTEMPTS 100 +#define UG_WRITE_ATTEMPTS 100 + + +static void __iomem *ug_io_base; + +/* + * Performs one input/output transaction between the exi host and the usbgecko. + */ +static u32 ug_io_transaction(u32 in) +{ + u32 __iomem *csr_reg = ug_io_base + EXI_CSR; + u32 __iomem *data_reg = ug_io_base + EXI_DATA; + u32 __iomem *cr_reg = ug_io_base + EXI_CR; + u32 csr, data, cr; + + /* select */ + csr = EXI_CSR_CLK_32MHZ | EXI_CSR_CS_0; + out_be32(csr_reg, csr); + + /* read/write */ + data = in; + out_be32(data_reg, data); + cr = EXI_CR_TLEN(2) | EXI_CR_READ_WRITE | EXI_CR_TSTART; + out_be32(cr_reg, cr); + + while (in_be32(cr_reg) & EXI_CR_TSTART) + barrier(); + + /* deselect */ + out_be32(csr_reg, 0); + + /* result */ + data = in_be32(data_reg); + + return data; +} + +/* + * Returns true if an usbgecko adapter is found. + */ +static int ug_is_adapter_present(void) +{ + if (!ug_io_base) + return 0; + + return ug_io_transaction(0x90000000) == 0x04700000; +} + +/* + * Returns true if the TX fifo is ready for transmission. + */ +static int ug_is_txfifo_ready(void) +{ + return ug_io_transaction(0xc0000000) & 0x04000000; +} + +/* + * Tries to transmit a character. + * If the TX fifo is not ready the result is undefined. + */ +static void ug_raw_putc(char ch) +{ + ug_io_transaction(0xb0000000 | (ch << 20)); +} + +/* + * Transmits a character. + * It silently fails if the TX fifo is not ready after a number of retries. + */ +static void ug_putc(char ch) +{ + int count = UG_WRITE_ATTEMPTS; + + if (!ug_io_base) + return; + + if (ch == '\n') + ug_putc('\r'); + + while (!ug_is_txfifo_ready() && count--) + barrier(); + if (count >= 0) + ug_raw_putc(ch); +} + +/* + * Returns true if the RX fifo is ready for transmission. + */ +static int ug_is_rxfifo_ready(void) +{ + return ug_io_transaction(0xd0000000) & 0x04000000; +} + +/* + * Tries to receive a character. + * If a character is unavailable the function returns -1. + */ +static int ug_raw_getc(void) +{ + u32 data = ug_io_transaction(0xa0000000); + if (data & 0x08000000) + return (data >> 16) & 0xff; + else + return -1; +} + +/* + * Receives a character. + * It fails if the RX fifo is not ready after a number of retries. + */ +static int ug_getc(void) +{ + int count = UG_READ_ATTEMPTS; + + if (!ug_io_base) + return -1; + + while (!ug_is_rxfifo_ready() && count--) + barrier(); + return ug_raw_getc(); +} + +/* + * udbg functions. + * + */ + +/* + * Transmits a character. + */ +static void ug_udbg_putc(char ch) +{ + ug_putc(ch); +} + +/* + * Receives a character. Waits until a character is available. + */ +static int ug_udbg_getc(void) +{ + int ch; + + while ((ch = ug_getc()) == -1) + barrier(); + return ch; +} + +/* + * Receives a character. If a character is not available, returns -1. + */ +static int ug_udbg_getc_poll(void) +{ + if (!ug_is_rxfifo_ready()) + return -1; + return ug_getc(); +} + +/* + * Retrieves and prepares the virtual address needed to access the hardware. + */ +static void __iomem *__init ug_udbg_setup_exi_io_base(struct device_node *np) +{ + void __iomem *exi_io_base = NULL; + phys_addr_t paddr; + const unsigned int *reg; + + reg = of_get_property(np, "reg", NULL); + if (reg) { + paddr = of_translate_address(np, reg); + if (paddr) + exi_io_base = ioremap(paddr, reg[1]); + } + return exi_io_base; +} + +/* + * Checks if a USB Gecko adapter is inserted in any memory card slot. + */ +static void __iomem *__init ug_udbg_probe(void __iomem *exi_io_base) +{ + int i; + + /* look for a usbgecko on memcard slots A and B */ + for (i = 0; i < 2; i++) { + ug_io_base = exi_io_base + 0x14 * i; + if (ug_is_adapter_present()) + break; + } + if (i == 2) + ug_io_base = NULL; + return ug_io_base; + +} + +/* + * USB Gecko udbg support initialization. + */ +void __init ug_udbg_init(void) +{ + struct device_node *np; + void __iomem *exi_io_base; + + if (ug_io_base) + udbg_printf("%s: early -> final\n", __func__); + + np = of_find_compatible_node(NULL, NULL, "nintendo,flipper-exi"); + if (!np) { + udbg_printf("%s: EXI node not found\n", __func__); + goto out; + } + + exi_io_base = ug_udbg_setup_exi_io_base(np); + if (!exi_io_base) { + udbg_printf("%s: failed to setup EXI io base\n", __func__); + goto done; + } + + if (!ug_udbg_probe(exi_io_base)) { + udbg_printf("usbgecko_udbg: not found\n"); + iounmap(exi_io_base); + } else { + udbg_putc = ug_udbg_putc; + udbg_getc = ug_udbg_getc; + udbg_getc_poll = ug_udbg_getc_poll; + udbg_printf("usbgecko_udbg: ready\n"); + } + +done: + of_node_put(np); +out: + return; +} + +#ifdef CONFIG_PPC_EARLY_DEBUG_USBGECKO + +static phys_addr_t __init ug_early_grab_io_addr(void) +{ +#if defined(CONFIG_GAMECUBE) + return 0x0c000000; +#elif defined(CONFIG_WII) + return 0x0d000000; +#else +#error Invalid platform for USB Gecko based early debugging. +#endif +} + +/* + * USB Gecko early debug support initialization for udbg. + */ +void __init udbg_init_usbgecko(void) +{ + void __iomem *early_debug_area; + void __iomem *exi_io_base; + + /* + * At this point we have a BAT already setup that enables I/O + * to the EXI hardware. + * + * The BAT uses a virtual address range reserved at the fixmap. + * This must match the virtual address configured in + * head_32.S:setup_usbgecko_bat(). + */ + early_debug_area = (void __iomem *)__fix_to_virt(FIX_EARLY_DEBUG_BASE); + exi_io_base = early_debug_area + 0x00006800; + + /* try to detect a USB Gecko */ + if (!ug_udbg_probe(exi_io_base)) + return; + + /* we found a USB Gecko, load udbg hooks */ + udbg_putc = ug_udbg_putc; + udbg_getc = ug_udbg_getc; + udbg_getc_poll = ug_udbg_getc_poll; + + /* + * Prepare again the same BAT for MMU_init. + * This allows udbg I/O to continue working after the MMU is + * turned on for real. + * It is safe to continue using the same virtual address as it is + * a reserved fixmap area. + */ + setbat(1, (unsigned long)early_debug_area, + ug_early_grab_io_addr(), 128*1024, PAGE_KERNEL_NCG); +} + +#endif /* CONFIG_PPC_EARLY_DEBUG_USBGECKO */ + |