--- /dev/null
+/*
+ * 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
+ *
+ * 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.
+ *
+ */
+
+#include <mm/mmu_decl.h>
+
+#include <asm/io.h>
+#include <asm/prom.h>
+#include <asm/udbg.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)
+ 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.
+ */
+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 *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 *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 done;
+ }
+
+ 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:
+ if (np)
+ of_node_put(np);
+ return;
+}
projects / linux-platform-drivers-x86.git / commitdiff