serial: serial_octeon_pcie_console.c: Add PCI remote console support
authorStefan Roese <sr@denx.de>
Wed, 7 Apr 2021 07:12:30 +0000 (09:12 +0200)
committerStefan Roese <sr@denx.de>
Wed, 28 Apr 2021 08:05:12 +0000 (10:05 +0200)
This patch adds the PCI remote console feature for MIPS Octeon, which
will be used by the upcoming Octeon III NIC23 board support. It enables
the use of the "oct-remote-console" tool on host PC's to communicate
with the PCIe target.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Aaron Williams <awilliams@marvell.com>
Cc: Chandrakala Chavva <cchavva@marvell.com>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
drivers/serial/Kconfig
drivers/serial/Makefile
drivers/serial/serial_octeon_pcie_console.c [new file with mode: 0644]

index af83e96..b42bc73 100644 (file)
@@ -788,6 +788,19 @@ config MSM_SERIAL
          for example APQ8016 and MSM8916.
          Single baudrate is supported in current implementation (115200).
 
+config OCTEON_SERIAL_PCIE_CONSOLE
+       bool "MIPS Octeon PCIe remote console"
+       depends on ARCH_OCTEON
+       depends on (DM_SERIAL && DM_STDIO)
+       select SYS_STDIO_DEREGISTER
+       select SYS_CONSOLE_IS_IN_ENV
+       select CONSOLE_MUX
+       help
+         This driver supports remote console over the PCIe bus when the
+         Octeon is running in PCIe target mode. The host program
+         'oct-remote-console' can be used to connect to this console.
+         The console number will likely be 0 or 1.
+
 config OMAP_SERIAL
        bool "Support for OMAP specific UART"
        depends on DM_SERIAL
index 92bcb30..4900e9c 100644 (file)
@@ -66,6 +66,7 @@ obj-$(CONFIG_MSM_SERIAL) += serial_msm.o
 obj-$(CONFIG_MVEBU_A3700_UART) += serial_mvebu_a3700.o
 obj-$(CONFIG_MPC8XX_CONS) += serial_mpc8xx.o
 obj-$(CONFIG_NULLDEV_SERIAL) += serial_nulldev.o
+obj-$(CONFIG_OCTEON_SERIAL_PCIE_CONSOLE) += serial_octeon_pcie_console.o
 obj-$(CONFIG_OWL_SERIAL) += serial_owl.o
 obj-$(CONFIG_OMAP_SERIAL) += serial_omap.o
 obj-$(CONFIG_MTK_SERIAL) += serial_mtk.o
diff --git a/drivers/serial/serial_octeon_pcie_console.c b/drivers/serial/serial_octeon_pcie_console.c
new file mode 100644 (file)
index 0000000..c76e787
--- /dev/null
@@ -0,0 +1,365 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2019 Marvell International Ltd.
+ * Copyright (C) 2021 Stefan Roese <sr@denx.de>
+ */
+
+#include <dm.h>
+#include <dm/uclass.h>
+#include <errno.h>
+#include <input.h>
+#include <iomux.h>
+#include <log.h>
+#include <serial.h>
+#include <stdio_dev.h>
+#include <string.h>
+#include <watchdog.h>
+#include <linux/delay.h>
+#include <asm/io.h>
+#include <mach/cvmx-regs.h>
+#include <mach/cvmx-bootmem.h>
+
+#define DRIVER_NAME                            "pci-console"
+#define OCTEONTX_PCIE_CONSOLE_NAME_LEN         16
+
+/* Current versions */
+#define OCTEON_PCIE_CONSOLE_MAJOR_VERSION      1
+#define OCTEON_PCIE_CONSOLE_MINOR_VERSION      0
+
+#define OCTEON_PCIE_CONSOLE_BLOCK_NAME         "__pci_console"
+
+/*
+ * Structure that defines a single console.
+ * Note: when read_index == write_index, the buffer is empty.
+ * The actual usable size of each console is console_buf_size -1;
+ */
+struct octeon_pcie_console {
+       u64 input_base_addr;
+       u32 input_read_index;
+       u32 input_write_index;
+       u64 output_base_addr;
+       u32 output_read_index;
+       u32 output_write_index;
+       u32 lock;
+       u32 buf_size;
+};
+
+/*
+ * This is the main container structure that contains all the information
+ * about all PCI consoles. The address of this structure is passed to various
+ * routines that operation on PCI consoles.
+ */
+struct octeon_pcie_console_desc {
+       u32 major_version;
+       u32 minor_version;
+       u32 lock;
+       u32 flags;
+       u32 num_consoles;
+       u32 pad;
+       /* must be 64 bit aligned here... */
+       /* Array of addresses of octeon_pcie_console_t structures */
+       u64 console_addr_array[0];
+       /* Implicit storage for console_addr_array */
+};
+
+struct octeon_pcie_console_priv {
+       struct octeon_pcie_console *console;
+       int console_num;
+       bool console_active;
+};
+
+/* Flag definitions for read/write functions */
+enum {
+       /*
+        * If set, read/write functions won't block waiting for space or data.
+        * For reads, 0 bytes may be read, and for writes not all of the
+        * supplied data may be written.
+        */
+       OCT_PCI_CON_FLAG_NONBLOCK = 1 << 0,
+};
+
+static int buffer_free_bytes(u32 buffer_size, u32 wr_idx, u32 rd_idx)
+{
+       if (rd_idx >= buffer_size || wr_idx >= buffer_size)
+               return -1;
+
+       return ((buffer_size - 1) - (wr_idx - rd_idx)) % buffer_size;
+}
+
+static int buffer_avail_bytes(u32 buffer_size, u32 wr_idx, u32 rd_idx)
+{
+       if (rd_idx >= buffer_size || wr_idx >= buffer_size)
+               return -1;
+
+       return buffer_size - 1 - buffer_free_bytes(buffer_size, wr_idx, rd_idx);
+}
+
+static int buffer_read_avail(struct udevice *dev, unsigned int console_num)
+{
+       struct octeon_pcie_console_priv *priv = dev_get_priv(dev);
+       struct octeon_pcie_console *cons_ptr = priv->console;
+       int avail;
+
+       avail = buffer_avail_bytes(cons_ptr->buf_size,
+                                  cons_ptr->input_write_index,
+                                  cons_ptr->input_read_index);
+       if (avail >= 0)
+               return avail;
+
+       return 0;
+}
+
+static int octeon_pcie_console_read(struct udevice *dev,
+                                   unsigned int console_num, char *buffer,
+                                   int buffer_size, u32 flags)
+{
+       struct octeon_pcie_console_priv *priv = dev_get_priv(dev);
+       struct octeon_pcie_console *cons_ptr = priv->console;
+       int avail;
+       char *buf_ptr;
+       int bytes_read;
+       int read_size;
+
+       buf_ptr = (char *)cvmx_phys_to_ptr(cons_ptr->input_base_addr);
+
+       avail = buffer_avail_bytes(cons_ptr->buf_size,
+                                  cons_ptr->input_write_index,
+                                  cons_ptr->input_read_index);
+       if (avail < 0)
+               return avail;
+
+       if (!(flags & OCT_PCI_CON_FLAG_NONBLOCK)) {
+               /* Wait for some data to be available */
+               while (0 == (avail = buffer_avail_bytes(cons_ptr->buf_size,
+                                                       cons_ptr->input_write_index,
+                                                       cons_ptr->input_read_index))) {
+                       mdelay(10);
+                       WATCHDOG_RESET();
+               }
+       }
+
+       bytes_read = 0;
+
+       /* Don't overflow the buffer passed to us */
+       read_size = min_t(int, avail, buffer_size);
+
+       /* Limit ourselves to what we can input in a contiguous block */
+       if (cons_ptr->input_read_index + read_size >= cons_ptr->buf_size)
+               read_size = cons_ptr->buf_size - cons_ptr->input_read_index;
+
+       memcpy(buffer, buf_ptr + cons_ptr->input_read_index, read_size);
+       cons_ptr->input_read_index =
+               (cons_ptr->input_read_index + read_size) % cons_ptr->buf_size;
+       bytes_read += read_size;
+
+       /* Mark the PCIe console to be active from now on */
+       if (bytes_read)
+               priv->console_active = true;
+
+       return bytes_read;
+}
+
+static int octeon_pcie_console_write(struct udevice *dev,
+                                    unsigned int console_num,
+                                    const char *buffer,
+                                    int bytes_to_write, u32 flags)
+{
+       struct octeon_pcie_console_priv *priv = dev_get_priv(dev);
+       struct octeon_pcie_console *cons_ptr = priv->console;
+       int avail;
+       char *buf_ptr;
+       int bytes_written;
+
+       buf_ptr = (char *)cvmx_phys_to_ptr(cons_ptr->output_base_addr);
+       bytes_written = 0;
+       while (bytes_to_write > 0) {
+               avail = buffer_free_bytes(cons_ptr->buf_size,
+                                         cons_ptr->output_write_index,
+                                         cons_ptr->output_read_index);
+
+               if (avail > 0) {
+                       int write_size = min_t(int, avail, bytes_to_write);
+
+                       /*
+                        * Limit ourselves to what we can output in a contiguous
+                        * block
+                        */
+                       if (cons_ptr->output_write_index + write_size >=
+                           cons_ptr->buf_size) {
+                               write_size = cons_ptr->buf_size -
+                                            cons_ptr->output_write_index;
+                       }
+
+                       memcpy(buf_ptr + cons_ptr->output_write_index,
+                              buffer + bytes_written, write_size);
+                       /*
+                        * Make sure data is visible before changing write
+                        * index
+                        */
+                       CVMX_SYNCW;
+                       cons_ptr->output_write_index =
+                               (cons_ptr->output_write_index + write_size) %
+                               cons_ptr->buf_size;
+                       bytes_to_write -= write_size;
+                       bytes_written += write_size;
+               } else if (avail == 0) {
+                       /*
+                        * Check to see if we should wait for room, or return
+                        * after a partial write
+                        */
+                       if (flags & OCT_PCI_CON_FLAG_NONBLOCK)
+                               goto done;
+
+                       WATCHDOG_RESET();
+                       mdelay(10);     /* Delay if we are spinning */
+               } else {
+                       bytes_written = -1;
+                       goto done;
+               }
+       }
+
+done:
+       return bytes_written;
+}
+
+static struct octeon_pcie_console_desc *octeon_pcie_console_init(int num_consoles,
+                                                                int buffer_size)
+{
+       struct octeon_pcie_console_desc *cons_desc_ptr;
+       struct octeon_pcie_console *cons_ptr;
+       s64 addr;
+       u64 avail_addr;
+       int alloc_size;
+       int i;
+
+       /* Compute size required for pci console structure */
+       alloc_size = num_consoles *
+               (buffer_size * 2 + sizeof(struct octeon_pcie_console) +
+                sizeof(u64)) + sizeof(struct octeon_pcie_console_desc);
+
+       /*
+        * Allocate memory for the consoles.  This must be in the range
+        * addresssible by the bootloader.
+        * Try to do so in a manner which minimizes fragmentation.  We try to
+        * put it at the top of DDR0 or bottom of DDR2 first, and only do
+        * generic allocation if those fail
+        */
+       addr = cvmx_bootmem_phy_named_block_alloc(alloc_size,
+                                                 OCTEON_DDR0_SIZE - alloc_size - 128,
+                                                 OCTEON_DDR0_SIZE, 128,
+                                                 OCTEON_PCIE_CONSOLE_BLOCK_NAME,
+                                                 CVMX_BOOTMEM_FLAG_END_ALLOC);
+       if (addr < 0) {
+               addr = cvmx_bootmem_phy_named_block_alloc(alloc_size, 0,
+                                                         0x1fffffff, 128,
+                                                         OCTEON_PCIE_CONSOLE_BLOCK_NAME,
+                                                         CVMX_BOOTMEM_FLAG_END_ALLOC);
+       }
+       if (addr < 0)
+               return 0;
+
+       cons_desc_ptr = cvmx_phys_to_ptr(addr);
+
+       /* Clear entire alloc'ed memory */
+       memset(cons_desc_ptr, 0, alloc_size);
+
+       /* Initialize as locked until we are done */
+       cons_desc_ptr->lock = 1;
+       CVMX_SYNCW;
+       cons_desc_ptr->num_consoles = num_consoles;
+       cons_desc_ptr->flags = 0;
+       cons_desc_ptr->major_version = OCTEON_PCIE_CONSOLE_MAJOR_VERSION;
+       cons_desc_ptr->minor_version = OCTEON_PCIE_CONSOLE_MINOR_VERSION;
+
+       avail_addr = addr + sizeof(struct octeon_pcie_console_desc) +
+               num_consoles * sizeof(u64);
+
+       for (i = 0; i < num_consoles; i++) {
+               cons_desc_ptr->console_addr_array[i] = avail_addr;
+               cons_ptr = (void *)cons_desc_ptr->console_addr_array[i];
+               avail_addr += sizeof(struct octeon_pcie_console);
+               cons_ptr->input_base_addr = avail_addr;
+               avail_addr += buffer_size;
+               cons_ptr->output_base_addr = avail_addr;
+               avail_addr += buffer_size;
+               cons_ptr->buf_size = buffer_size;
+       }
+       CVMX_SYNCW;
+       cons_desc_ptr->lock = 0;
+
+       return cvmx_phys_to_ptr(addr);
+}
+
+static int octeon_pcie_console_getc(struct udevice *dev)
+{
+       char c;
+
+       octeon_pcie_console_read(dev, 0, &c, 1, 0);
+       return c;
+}
+
+static int octeon_pcie_console_putc(struct udevice *dev, const char c)
+{
+       struct octeon_pcie_console_priv *priv = dev_get_priv(dev);
+
+       if (priv->console_active)
+               octeon_pcie_console_write(dev, 0, (char *)&c, 1, 0);
+
+       return 0;
+}
+
+static int octeon_pcie_console_pending(struct udevice *dev, bool input)
+{
+       if (input) {
+               udelay(100);
+               return buffer_read_avail(dev, 0) > 0;
+       }
+
+       return 0;
+}
+
+static const struct dm_serial_ops octeon_pcie_console_ops = {
+       .getc = octeon_pcie_console_getc,
+       .putc = octeon_pcie_console_putc,
+       .pending = octeon_pcie_console_pending,
+};
+
+static int octeon_pcie_console_probe(struct udevice *dev)
+{
+       struct octeon_pcie_console_priv *priv = dev_get_priv(dev);
+       struct octeon_pcie_console_desc *cons_desc;
+       int console_count;
+       int console_size;
+       int console_num;
+
+       /*
+        * Currently only 1 console is supported. Perhaps we need to add
+        * a console nexus if more than one needs to be supported.
+        */
+       console_count = 1;
+       console_size = 1024;
+       console_num = 0;
+
+       cons_desc = octeon_pcie_console_init(console_count, console_size);
+       priv->console =
+               cvmx_phys_to_ptr(cons_desc->console_addr_array[console_num]);
+
+       debug("PCI console init succeeded, %d consoles, %d bytes each\n",
+             console_count, console_size);
+
+       return 0;
+}
+
+static const struct udevice_id octeon_pcie_console_serial_id[] = {
+       { .compatible = "marvell,pci-console", },
+       { },
+};
+
+U_BOOT_DRIVER(octeon_pcie_console) = {
+       .name = DRIVER_NAME,
+       .id = UCLASS_SERIAL,
+       .ops = &octeon_pcie_console_ops,
+       .of_match = of_match_ptr(octeon_pcie_console_serial_id),
+       .probe = octeon_pcie_console_probe,
+       .priv_auto = sizeof(struct octeon_pcie_console_priv),
+};