8250/16?50: Add support for Broadcom TruManage redirected serial port

Add support for the UART device present in Broadcom TruManage capable
NetXtreme chips (ie: 5761m 5762, and 5725).

This implementation has a hidden transmit FIFO, so running in single-byte
interrupt mode results in too many interrupts.  The UART_CAP_HFIFO
capability was added to track this.  It continues to reload the THR as long
as the THRE and TSRE bits are set in the LSR up to a specified limit (1024
is used here).

Signed-off-by: Stephen Hurd <shurd@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 50 insertions, 0 deletions

diff --git a/drivers/tty/serial/8250/8250.c b/drivers/tty/serial/8250/8250.c
index d085e3a8ec06..f9320437a649 100644
--- a/drivers/tty/serial/8250/8250.c
+++ b/drivers/tty/serial/8250/8250.c
@@ -300,6 +300,12 @@ static const struct serial8250_config uart_config[] = {
                                   UART_FCR_R_TRIG_00 | UART_FCR_T_TRIG_00,
                 .flags          = UART_CAP_FIFO,
         },
+        [PORT_BRCM_TRUMANAGE] = {
+                .name           = "TruManage",
+                .fifo_size      = 1,
+                .tx_loadsz      = 1024,
+                .flags          = UART_CAP_HFIFO,
+        },
         [PORT_8250_CIR] = {
                 .name           = "CIR port"
         }
@@ -1490,6 +1496,11 @@ void serial8250_tx_chars(struct uart_8250_port *up)
                 port->icount.tx++;
                 if (uart_circ_empty(xmit))
                         break;
+                if (up->capabilities & UART_CAP_HFIFO) {
+                        if ((serial_port_in(port, UART_LSR) & BOTH_EMPTY) !=
+                            BOTH_EMPTY)
+                                break;
+                }
         } while (--count > 0);
 
         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index 3b4ea84898c2..12caa1292b75 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -40,6 +40,7 @@ struct serial8250_config {
 #define UART_CAP_AFE    (1 << 11)       /* MCR-based hw flow control */
 #define UART_CAP_UUE    (1 << 12)       /* UART needs IER bit 6 set (Xscale) */
 #define UART_CAP_RTOIE  (1 << 13)       /* UART needs IER bit 4 set (Xscale, Tegra) */
+#define UART_CAP_HFIFO  (1 << 14)       /* UART has a "hidden" FIFO */
 
 #define UART_BUG_QUOT   (1 << 0)        /* UART has buggy quot LSB */
 #define UART_BUG_TXEN   (1 << 1)        /* UART has buggy TX IIR status */
diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
index 8a2c3d934187..a27a98e1b066 100644
--- a/drivers/tty/serial/8250/8250_pci.c
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -1085,6 +1085,18 @@ pci_omegapci_setup(struct serial_private *priv,
         return setup_port(priv, port, 2, idx * 8, 0);
 }
 
+static int
+pci_brcm_trumanage_setup(struct serial_private *priv,
+                         const struct pciserial_board *board,
+                         struct uart_8250_port *port, int idx)
+{
+        int ret = pci_default_setup(priv, board, port, idx);
+
+        port->port.type = PORT_BRCM_TRUMANAGE;
+        port->port.flags = (port->port.flags | UPF_FIXED_PORT | UPF_FIXED_TYPE);
+        return ret;
+}
+
 static int skip_tx_en_setup(struct serial_private *priv,
                         const struct pciserial_board *board,
                         struct uart_8250_port *port, int idx)
@@ -1304,6 +1316,7 @@ pci_wch_ch353_setup(struct serial_private *priv,
 #define PCI_DEVICE_ID_COMMTECH_4224PCIE 0x0020
 #define PCI_DEVICE_ID_COMMTECH_4228PCIE 0x0021
 #define PCI_DEVICE_ID_COMMTECH_4222PCIE 0x0022
+#define PCI_DEVICE_ID_BROADCOM_TRUMANAGE 0x160a
 
 
 /* Unknown vendors/cards - this should not be in linux/pci_ids.h */
@@ -1954,6 +1967,17 @@ static struct pci_serial_quirk pci_serial_quirks[] __refdata = {
                 .setup          = pci_xr17v35x_setup,
         },
         /*
+         * Broadcom TruManage (NetXtreme)
+         */
+        {
+                .vendor         = PCI_VENDOR_ID_BROADCOM,
+                .device         = PCI_DEVICE_ID_BROADCOM_TRUMANAGE,
+                .subvendor      = PCI_ANY_ID,
+                .subdevice      = PCI_ANY_ID,
+                .setup          = pci_brcm_trumanage_setup,
+        },
+
+        /*
          * Default "match everything" terminator entry
          */
         {
@@ -2148,6 +2172,7 @@ enum pci_board_num_t {
         pbn_ce4100_1_115200,
         pbn_omegapci,
         pbn_NETMOS9900_2s_115200,
+        pbn_brcm_trumanage,
 };
 
 /*
@@ -2892,6 +2917,12 @@ static struct pciserial_board pci_boards[] = {
                 .num_ports      = 2,
                 .base_baud      = 115200,
         },
+        [pbn_brcm_trumanage] = {
+                .flags          = FL_BASE0,
+                .num_ports      = 1,
+                .reg_shift      = 2,
+                .base_baud      = 115200,
+        },
 };
 
 static const struct pci_device_id blacklist[] = {
@@ -4471,6 +4502,13 @@ static struct pci_device_id serial_pci_tbl[] = {
                 pbn_omegapci },
 
         /*
+         * Broadcom TruManage
+         */
+        {       PCI_VENDOR_ID_BROADCOM, PCI_DEVICE_ID_BROADCOM_TRUMANAGE,
+                PCI_ANY_ID, PCI_ANY_ID, 0, 0,
+                pbn_brcm_trumanage },
+
+        /*
          * AgeStar as-prs2-009
          */
         {       PCI_VENDOR_ID_AGESTAR, PCI_DEVICE_ID_AGESTAR_9375,