USB: add Cypress c67x00 low level interface code

This patch adds the low level support code for the Cypress c67x00 family of
OTG controllers.  The low level code is responsible for register access and
implements the software protocol for communicating with the 16bit
microcontroller inside the c67x00 device.

Communication is done over the HPI interface (16bit SRAM-like parallel bus).

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 405 insertions, 0 deletions

diff --git a/drivers/usb/c67x00/c67x00-ll-hpi.c b/drivers/usb/c67x00/c67x00-ll-hpi.c
new file mode 100644
index 000000000000..e921991bc36a
--- /dev/null
+++ b/drivers/usb/c67x00/c67x00-ll-hpi.c
@@ -0,0 +1,405 @@
+/*
+ * c67x00-ll-hpi.c: Cypress C67X00 USB Low level interface using HPI
+ *
+ * Copyright (C) 2006-2008 Barco N.V.
+ *    Derived from the Cypress cy7c67200/300 ezusb linux driver and
+ *    based on multiple host controller drivers inside the linux kernel.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA  02110-1301  USA.
+ */
+
+#include <asm/byteorder.h>
+#include <linux/io.h>
+#include <linux/usb/c67x00.h>
+#include "c67x00.h"
+
+#define COMM_REGS 14
+
+struct c67x00_lcp_int_data {
+        u16 regs[COMM_REGS];
+};
+
+/* -------------------------------------------------------------------------- */
+/* Interface definitions */
+
+#define COMM_ACK                        0x0FED
+#define COMM_NAK                        0xDEAD
+
+#define COMM_RESET                      0xFA50
+#define COMM_EXEC_INT                   0xCE01
+#define COMM_INT_NUM                    0x01C2
+
+/* Registers 0 to COMM_REGS-1 */
+#define COMM_R(x)                       (0x01C4 + 2 * (x))
+
+#define HUSB_SIE_pCurrentTDPtr(x)       ((x) ? 0x01B2 : 0x01B0)
+#define HUSB_SIE_pTDListDone_Sem(x)     ((x) ? 0x01B8 : 0x01B6)
+#define HUSB_pEOT                       0x01B4
+
+/* Software interrupts */
+/* 114, 115: */
+#define HUSB_SIE_INIT_INT(x)            ((x) ? 0x0073 : 0x0072)
+#define HUSB_RESET_INT                  0x0074
+
+#define SUSB_INIT_INT                   0x0071
+#define SUSB_INIT_INT_LOC               (SUSB_INIT_INT * 2)
+
+/* -----------------------------------------------------------------------
+ * HPI implementation
+ *
+ * The c67x00 chip also support control via SPI or HSS serial
+ * interfaces.  However, this driver assumes that register access can
+ * be performed from IRQ context.  While this is a safe assuption with
+ * the HPI interface, it is not true for the serial interfaces.
+ */
+
+/* HPI registers */
+#define HPI_DATA        0
+#define HPI_MAILBOX     1
+#define HPI_ADDR        2
+#define HPI_STATUS      3
+
+static inline u16 hpi_read_reg(struct c67x00_device *dev, int reg)
+{
+        return __raw_readw(dev->hpi.base + reg * dev->hpi.regstep);
+}
+
+static inline void hpi_write_reg(struct c67x00_device *dev, int reg, u16 value)
+{
+        __raw_writew(value, dev->hpi.base + reg * dev->hpi.regstep);
+}
+
+static inline u16 hpi_read_word_nolock(struct c67x00_device *dev, u16 reg)
+{
+        hpi_write_reg(dev, HPI_ADDR, reg);
+        return hpi_read_reg(dev, HPI_DATA);
+}
+
+static u16 hpi_read_word(struct c67x00_device *dev, u16 reg)
+{
+        u16 value;
+        unsigned long flags;
+
+        spin_lock_irqsave(&dev->hpi.lock, flags);
+        value = hpi_read_word_nolock(dev, reg);
+        spin_unlock_irqrestore(&dev->hpi.lock, flags);
+
+        return value;
+}
+
+static void hpi_write_word_nolock(struct c67x00_device *dev, u16 reg, u16 value)
+{
+        hpi_write_reg(dev, HPI_ADDR, reg);
+        hpi_write_reg(dev, HPI_DATA, value);
+}
+
+static void hpi_write_word(struct c67x00_device *dev, u16 reg, u16 value)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&dev->hpi.lock, flags);
+        hpi_write_word_nolock(dev, reg, value);
+        spin_unlock_irqrestore(&dev->hpi.lock, flags);
+}
+
+/*
+ * Only data is little endian, addr has cpu endianess
+ */
+static void hpi_write_words_le16(struct c67x00_device *dev, u16 addr,
+                                 u16 *data, u16 count)
+{
+        unsigned long flags;
+        int i;
+
+        spin_lock_irqsave(&dev->hpi.lock, flags);
+
+        hpi_write_reg(dev, HPI_ADDR, addr);
+        for (i = 0; i < count; i++)
+                hpi_write_reg(dev, HPI_DATA, cpu_to_le16(*data++));
+
+        spin_unlock_irqrestore(&dev->hpi.lock, flags);
+}
+
+/*
+ * Only data is little endian, addr has cpu endianess
+ */
+static void hpi_read_words_le16(struct c67x00_device *dev, u16 addr,
+                                u16 *data, u16 count)
+{
+        unsigned long flags;
+        int i;
+
+        spin_lock_irqsave(&dev->hpi.lock, flags);
+        hpi_write_reg(dev, HPI_ADDR, addr);
+        for (i = 0; i < count; i++)
+                *data++ = le16_to_cpu(hpi_read_reg(dev, HPI_DATA));
+
+        spin_unlock_irqrestore(&dev->hpi.lock, flags);
+}
+
+static void hpi_set_bits(struct c67x00_device *dev, u16 reg, u16 mask)
+{
+        u16 value;
+        unsigned long flags;
+
+        spin_lock_irqsave(&dev->hpi.lock, flags);
+        value = hpi_read_word_nolock(dev, reg);
+        hpi_write_word_nolock(dev, reg, value | mask);
+        spin_unlock_irqrestore(&dev->hpi.lock, flags);
+}
+
+static void hpi_clear_bits(struct c67x00_device *dev, u16 reg, u16 mask)
+{
+        u16 value;
+        unsigned long flags;
+
+        spin_lock_irqsave(&dev->hpi.lock, flags);
+        value = hpi_read_word_nolock(dev, reg);
+        hpi_write_word_nolock(dev, reg, value & ~mask);
+        spin_unlock_irqrestore(&dev->hpi.lock, flags);
+}
+
+static u16 hpi_recv_mbox(struct c67x00_device *dev)
+{
+        u16 value;
+        unsigned long flags;
+
+        spin_lock_irqsave(&dev->hpi.lock, flags);
+        value = hpi_read_reg(dev, HPI_MAILBOX);
+        spin_unlock_irqrestore(&dev->hpi.lock, flags);
+
+        return value;
+}
+
+static u16 hpi_send_mbox(struct c67x00_device *dev, u16 value)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&dev->hpi.lock, flags);
+        hpi_write_reg(dev, HPI_MAILBOX, value);
+        spin_unlock_irqrestore(&dev->hpi.lock, flags);
+
+        return value;
+}
+
+u16 c67x00_ll_hpi_status(struct c67x00_device *dev)
+{
+        u16 value;
+        unsigned long flags;
+
+        spin_lock_irqsave(&dev->hpi.lock, flags);
+        value = hpi_read_reg(dev, HPI_STATUS);
+        spin_unlock_irqrestore(&dev->hpi.lock, flags);
+
+        return value;
+}
+
+void c67x00_ll_hpi_reg_init(struct c67x00_device *dev)
+{
+        int i;
+
+        hpi_recv_mbox(dev);
+        c67x00_ll_hpi_status(dev);
+        hpi_write_word(dev, HPI_IRQ_ROUTING_REG, 0);
+
+        for (i = 0; i < C67X00_SIES; i++) {
+                hpi_write_word(dev, SIEMSG_REG(i), 0);
+                hpi_read_word(dev, SIEMSG_REG(i));
+        }
+}
+
+void c67x00_ll_hpi_enable_sofeop(struct c67x00_sie *sie)
+{
+        hpi_set_bits(sie->dev, HPI_IRQ_ROUTING_REG,
+                     SOFEOP_TO_HPI_EN(sie->sie_num));
+}
+
+void c67x00_ll_hpi_disable_sofeop(struct c67x00_sie *sie)
+{
+        hpi_clear_bits(sie->dev, HPI_IRQ_ROUTING_REG,
+                       SOFEOP_TO_HPI_EN(sie->sie_num));
+}
+
+/* -------------------------------------------------------------------------- */
+/* Transactions */
+
+static inline u16 ll_recv_msg(struct c67x00_device *dev)
+{
+        u16 res;
+
+        res = wait_for_completion_timeout(&dev->hpi.lcp.msg_received, 5 * HZ);
+        WARN_ON(!res);
+
+        return (res == 0) ? -EIO : 0;
+}
+
+/* -------------------------------------------------------------------------- */
+/* General functions */
+
+u16 c67x00_ll_fetch_siemsg(struct c67x00_device *dev, int sie_num)
+{
+        u16 val;
+
+        val = hpi_read_word(dev, SIEMSG_REG(sie_num));
+        /* clear register to allow next message */
+        hpi_write_word(dev, SIEMSG_REG(sie_num), 0);
+
+        return val;
+}
+
+u16 c67x00_ll_get_usb_ctl(struct c67x00_sie *sie)
+{
+        return hpi_read_word(sie->dev, USB_CTL_REG(sie->sie_num));
+}
+
+/**
+ * c67x00_ll_usb_clear_status - clear the USB status bits
+ */
+void c67x00_ll_usb_clear_status(struct c67x00_sie *sie, u16 bits)
+{
+        hpi_write_word(sie->dev, USB_STAT_REG(sie->sie_num), bits);
+}
+
+u16 c67x00_ll_usb_get_status(struct c67x00_sie *sie)
+{
+        return hpi_read_word(sie->dev, USB_STAT_REG(sie->sie_num));
+}
+
+/* -------------------------------------------------------------------------- */
+
+static int c67x00_comm_exec_int(struct c67x00_device *dev, u16 nr,
+                                struct c67x00_lcp_int_data *data)
+{
+        int i, rc;
+
+        mutex_lock(&dev->hpi.lcp.mutex);
+        hpi_write_word(dev, COMM_INT_NUM, nr);
+        for (i = 0; i < COMM_REGS; i++)
+                hpi_write_word(dev, COMM_R(i), data->regs[i]);
+        hpi_send_mbox(dev, COMM_EXEC_INT);
+        rc = ll_recv_msg(dev);
+        mutex_unlock(&dev->hpi.lcp.mutex);
+
+        return rc;
+}
+
+/* -------------------------------------------------------------------------- */
+
+void c67x00_ll_irq(struct c67x00_device *dev, u16 int_status)
+{
+        if ((int_status & MBX_OUT_FLG) == 0)
+                return;
+
+        dev->hpi.lcp.last_msg = hpi_recv_mbox(dev);
+        complete(&dev->hpi.lcp.msg_received);
+}
+
+/* -------------------------------------------------------------------------- */
+
+int c67x00_ll_reset(struct c67x00_device *dev)
+{
+        int rc;
+
+        mutex_lock(&dev->hpi.lcp.mutex);
+        hpi_send_mbox(dev, COMM_RESET);
+        rc = ll_recv_msg(dev);
+        mutex_unlock(&dev->hpi.lcp.mutex);
+
+        return rc;
+}
+
+/* -------------------------------------------------------------------------- */
+
+/**
+ * c67x00_ll_write_mem_le16 - write into c67x00 memory
+ * Only data is little endian, addr has cpu endianess.
+ */
+void c67x00_ll_write_mem_le16(struct c67x00_device *dev, u16 addr,
+                              void *data, int len)
+{
+        u8 *buf = data;
+
+        /* Sanity check */
+        if (addr + len > 0xffff) {
+                dev_err(&dev->pdev->dev,
+                        "Trying to write beyond writable region!\n");
+                return;
+        }
+
+        if (addr & 0x01) {
+                /* unaligned access */
+                u16 tmp;
+                tmp = hpi_read_word(dev, addr - 1);
+                tmp = (tmp & 0x00ff) | (*buf++ << 8);
+                hpi_write_word(dev, addr - 1, tmp);
+                addr++;
+                len--;
+        }
+
+        hpi_write_words_le16(dev, addr, (u16 *)buf, len / 2);
+        buf += len & ~0x01;
+        addr += len & ~0x01;
+        len &= 0x01;
+
+        if (len) {
+                u16 tmp;
+                tmp = hpi_read_word(dev, addr);
+                tmp = (tmp & 0xff00) | *buf;
+                hpi_write_word(dev, addr, tmp);
+        }
+}
+
+/**
+ * c67x00_ll_read_mem_le16 - read from c67x00 memory
+ * Only data is little endian, addr has cpu endianess.
+ */
+void c67x00_ll_read_mem_le16(struct c67x00_device *dev, u16 addr,
+                             void *data, int len)
+{
+        u8 *buf = data;
+
+        if (addr & 0x01) {
+                /* unaligned access */
+                u16 tmp;
+                tmp = hpi_read_word(dev, addr - 1);
+                *buf++ = (tmp >> 8) & 0x00ff;
+                addr++;
+                len--;
+        }
+
+        hpi_read_words_le16(dev, addr, (u16 *)buf, len / 2);
+        buf += len & ~0x01;
+        addr += len & ~0x01;
+        len &= 0x01;
+
+        if (len) {
+                u16 tmp;
+                tmp = hpi_read_word(dev, addr);
+                *buf = tmp & 0x00ff;
+        }
+}
+
+/* -------------------------------------------------------------------------- */
+
+void c67x00_ll_init(struct c67x00_device *dev)
+{
+        mutex_init(&dev->hpi.lcp.mutex);
+        init_completion(&dev->hpi.lcp.msg_received);
+}
+
+void c67x00_ll_release(struct c67x00_device *dev)
+{
+}