Add qemu 2.4.0
[kvmfornfv.git] / qemu / roms / u-boot / drivers / spi / ich.c
diff --git a/qemu/roms/u-boot/drivers/spi/ich.c b/qemu/roms/u-boot/drivers/spi/ich.c
new file mode 100644 (file)
index 0000000..f5c6f3e
--- /dev/null
@@ -0,0 +1,741 @@
+/*
+ * Copyright (c) 2011-12 The Chromium OS Authors.
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ *
+ * This file is derived from the flashrom project.
+ */
+
+#include <common.h>
+#include <malloc.h>
+#include <spi.h>
+#include <pci.h>
+#include <pci_ids.h>
+#include <asm/io.h>
+
+#include "ich.h"
+
+#define SPI_OPCODE_WREN      0x06
+#define SPI_OPCODE_FAST_READ 0x0b
+
+struct ich_ctlr {
+       pci_dev_t dev;          /* PCI device number */
+       int ich_version;        /* Controller version, 7 or 9 */
+       int ichspi_lock;
+       int locked;
+       uint8_t *opmenu;
+       int menubytes;
+       void *base;             /* Base of register set */
+       uint16_t *preop;
+       uint16_t *optype;
+       uint32_t *addr;
+       uint8_t *data;
+       unsigned databytes;
+       uint8_t *status;
+       uint16_t *control;
+       uint32_t *bbar;
+       uint32_t *pr;           /* only for ich9 */
+       uint8_t *speed;         /* pointer to speed control */
+       ulong max_speed;        /* Maximum bus speed in MHz */
+};
+
+struct ich_ctlr ctlr;
+
+static inline struct ich_spi_slave *to_ich_spi(struct spi_slave *slave)
+{
+       return container_of(slave, struct ich_spi_slave, slave);
+}
+
+static unsigned int ich_reg(const void *addr)
+{
+       return (unsigned)(addr - ctlr.base) & 0xffff;
+}
+
+static u8 ich_readb(const void *addr)
+{
+       u8 value = readb(addr);
+
+       debug("read %2.2x from %4.4x\n", value, ich_reg(addr));
+
+       return value;
+}
+
+static u16 ich_readw(const void *addr)
+{
+       u16 value = readw(addr);
+
+       debug("read %4.4x from %4.4x\n", value, ich_reg(addr));
+
+       return value;
+}
+
+static u32 ich_readl(const void *addr)
+{
+       u32 value = readl(addr);
+
+       debug("read %8.8x from %4.4x\n", value, ich_reg(addr));
+
+       return value;
+}
+
+static void ich_writeb(u8 value, void *addr)
+{
+       writeb(value, addr);
+       debug("wrote %2.2x to %4.4x\n", value, ich_reg(addr));
+}
+
+static void ich_writew(u16 value, void *addr)
+{
+       writew(value, addr);
+       debug("wrote %4.4x to %4.4x\n", value, ich_reg(addr));
+}
+
+static void ich_writel(u32 value, void *addr)
+{
+       writel(value, addr);
+       debug("wrote %8.8x to %4.4x\n", value, ich_reg(addr));
+}
+
+static void write_reg(const void *value, void *dest, uint32_t size)
+{
+       memcpy_toio(dest, value, size);
+}
+
+static void read_reg(const void *src, void *value, uint32_t size)
+{
+       memcpy_fromio(value, src, size);
+}
+
+static void ich_set_bbar(struct ich_ctlr *ctlr, uint32_t minaddr)
+{
+       const uint32_t bbar_mask = 0x00ffff00;
+       uint32_t ichspi_bbar;
+
+       minaddr &= bbar_mask;
+       ichspi_bbar = ich_readl(ctlr->bbar) & ~bbar_mask;
+       ichspi_bbar |= minaddr;
+       ich_writel(ichspi_bbar, ctlr->bbar);
+}
+
+int spi_cs_is_valid(unsigned int bus, unsigned int cs)
+{
+       puts("spi_cs_is_valid used but not implemented\n");
+       return 0;
+}
+
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+               unsigned int max_hz, unsigned int mode)
+{
+       struct ich_spi_slave *ich;
+
+       ich = spi_alloc_slave(struct ich_spi_slave, bus, cs);
+       if (!ich) {
+               puts("ICH SPI: Out of memory\n");
+               return NULL;
+       }
+
+       /*
+        * Yes this controller can only write a small number of bytes at
+        * once! The limit is typically 64 bytes.
+        */
+       ich->slave.max_write_size = ctlr.databytes;
+       ich->speed = max_hz;
+
+       return &ich->slave;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+       struct ich_spi_slave *ich = to_ich_spi(slave);
+
+       free(ich);
+}
+
+/*
+ * Check if this device ID matches one of supported Intel PCH devices.
+ *
+ * Return the ICH version if there is a match, or zero otherwise.
+ */
+static int get_ich_version(uint16_t device_id)
+{
+       if (device_id == PCI_DEVICE_ID_INTEL_TGP_LPC)
+               return 7;
+
+       if ((device_id >= PCI_DEVICE_ID_INTEL_COUGARPOINT_LPC_MIN &&
+            device_id <= PCI_DEVICE_ID_INTEL_COUGARPOINT_LPC_MAX) ||
+           (device_id >= PCI_DEVICE_ID_INTEL_PANTHERPOINT_LPC_MIN &&
+            device_id <= PCI_DEVICE_ID_INTEL_PANTHERPOINT_LPC_MAX))
+               return 9;
+
+       return 0;
+}
+
+/* @return 1 if the SPI flash supports the 33MHz speed */
+static int ich9_can_do_33mhz(pci_dev_t dev)
+{
+       u32 fdod, speed;
+
+       /* Observe SPI Descriptor Component Section 0 */
+       pci_write_config_dword(dev, 0xb0, 0x1000);
+
+       /* Extract the Write/Erase SPI Frequency from descriptor */
+       pci_read_config_dword(dev, 0xb4, &fdod);
+
+       /* Bits 23:21 have the fast read clock frequency, 0=20MHz, 1=33MHz */
+       speed = (fdod >> 21) & 7;
+
+       return speed == 1;
+}
+
+static int ich_find_spi_controller(pci_dev_t *devp, int *ich_versionp)
+{
+       int last_bus = pci_last_busno();
+       int bus;
+
+       if (last_bus == -1) {
+               debug("No PCI busses?\n");
+               return -1;
+       }
+
+       for (bus = 0; bus <= last_bus; bus++) {
+               uint16_t vendor_id, device_id;
+               uint32_t ids;
+               pci_dev_t dev;
+
+               dev = PCI_BDF(bus, 31, 0);
+               pci_read_config_dword(dev, 0, &ids);
+               vendor_id = ids;
+               device_id = ids >> 16;
+
+               if (vendor_id == PCI_VENDOR_ID_INTEL) {
+                       *devp = dev;
+                       *ich_versionp = get_ich_version(device_id);
+                       return 0;
+               }
+       }
+
+       debug("ICH SPI: No ICH found.\n");
+       return -1;
+}
+
+static int ich_init_controller(struct ich_ctlr *ctlr)
+{
+       uint8_t *rcrb; /* Root Complex Register Block */
+       uint32_t rcba; /* Root Complex Base Address */
+
+       pci_read_config_dword(ctlr->dev, 0xf0, &rcba);
+       /* Bits 31-14 are the base address, 13-1 are reserved, 0 is enable. */
+       rcrb = (uint8_t *)(rcba & 0xffffc000);
+       if (ctlr->ich_version == 7) {
+               struct ich7_spi_regs *ich7_spi;
+
+               ich7_spi = (struct ich7_spi_regs *)(rcrb + 0x3020);
+               ctlr->ichspi_lock = ich_readw(&ich7_spi->spis) & SPIS_LOCK;
+               ctlr->opmenu = ich7_spi->opmenu;
+               ctlr->menubytes = sizeof(ich7_spi->opmenu);
+               ctlr->optype = &ich7_spi->optype;
+               ctlr->addr = &ich7_spi->spia;
+               ctlr->data = (uint8_t *)ich7_spi->spid;
+               ctlr->databytes = sizeof(ich7_spi->spid);
+               ctlr->status = (uint8_t *)&ich7_spi->spis;
+               ctlr->control = &ich7_spi->spic;
+               ctlr->bbar = &ich7_spi->bbar;
+               ctlr->preop = &ich7_spi->preop;
+               ctlr->base = ich7_spi;
+       } else if (ctlr->ich_version == 9) {
+               struct ich9_spi_regs *ich9_spi;
+
+               ich9_spi = (struct ich9_spi_regs *)(rcrb + 0x3800);
+               ctlr->ichspi_lock = ich_readw(&ich9_spi->hsfs) & HSFS_FLOCKDN;
+               ctlr->opmenu = ich9_spi->opmenu;
+               ctlr->menubytes = sizeof(ich9_spi->opmenu);
+               ctlr->optype = &ich9_spi->optype;
+               ctlr->addr = &ich9_spi->faddr;
+               ctlr->data = (uint8_t *)ich9_spi->fdata;
+               ctlr->databytes = sizeof(ich9_spi->fdata);
+               ctlr->status = &ich9_spi->ssfs;
+               ctlr->control = (uint16_t *)ich9_spi->ssfc;
+               ctlr->speed = ich9_spi->ssfc + 2;
+               ctlr->bbar = &ich9_spi->bbar;
+               ctlr->preop = &ich9_spi->preop;
+               ctlr->pr = &ich9_spi->pr[0];
+               ctlr->base = ich9_spi;
+       } else {
+               debug("ICH SPI: Unrecognized ICH version %d.\n",
+                     ctlr->ich_version);
+               return -1;
+       }
+       debug("ICH SPI: Version %d detected\n", ctlr->ich_version);
+
+       /* Work out the maximum speed we can support */
+       ctlr->max_speed = 20000000;
+       if (ctlr->ich_version == 9 && ich9_can_do_33mhz(ctlr->dev))
+               ctlr->max_speed = 33000000;
+
+       ich_set_bbar(ctlr, 0);
+
+       return 0;
+}
+
+void spi_init(void)
+{
+       uint8_t bios_cntl;
+
+       if (ich_find_spi_controller(&ctlr.dev, &ctlr.ich_version)) {
+               printf("ICH SPI: Cannot find device\n");
+               return;
+       }
+
+       if (ich_init_controller(&ctlr)) {
+               printf("ICH SPI: Cannot setup controller\n");
+               return;
+       }
+
+       /*
+        * Disable the BIOS write protect so write commands are allowed.  On
+        * v9, deassert SMM BIOS Write Protect Disable.
+        */
+       pci_read_config_byte(ctlr.dev, 0xdc, &bios_cntl);
+       if (ctlr.ich_version == 9)
+               bios_cntl &= ~(1 << 5);
+       pci_write_config_byte(ctlr.dev, 0xdc, bios_cntl | 0x1);
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+       /* Handled by ICH automatically. */
+       return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+       /* Handled by ICH automatically. */
+}
+
+void spi_cs_activate(struct spi_slave *slave)
+{
+       /* Handled by ICH automatically. */
+}
+
+void spi_cs_deactivate(struct spi_slave *slave)
+{
+       /* Handled by ICH automatically. */
+}
+
+static inline void spi_use_out(struct spi_trans *trans, unsigned bytes)
+{
+       trans->out += bytes;
+       trans->bytesout -= bytes;
+}
+
+static inline void spi_use_in(struct spi_trans *trans, unsigned bytes)
+{
+       trans->in += bytes;
+       trans->bytesin -= bytes;
+}
+
+static void spi_setup_type(struct spi_trans *trans, int data_bytes)
+{
+       trans->type = 0xFF;
+
+       /* Try to guess spi type from read/write sizes. */
+       if (trans->bytesin == 0) {
+               if (trans->bytesout + data_bytes > 4)
+                       /*
+                        * If bytesin = 0 and bytesout > 4, we presume this is
+                        * a write data operation, which is accompanied by an
+                        * address.
+                        */
+                       trans->type = SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS;
+               else
+                       trans->type = SPI_OPCODE_TYPE_WRITE_NO_ADDRESS;
+               return;
+       }
+
+       if (trans->bytesout == 1) {     /* and bytesin is > 0 */
+               trans->type = SPI_OPCODE_TYPE_READ_NO_ADDRESS;
+               return;
+       }
+
+       if (trans->bytesout == 4)       /* and bytesin is > 0 */
+               trans->type = SPI_OPCODE_TYPE_READ_WITH_ADDRESS;
+
+       /* Fast read command is called with 5 bytes instead of 4 */
+       if (trans->out[0] == SPI_OPCODE_FAST_READ && trans->bytesout == 5) {
+               trans->type = SPI_OPCODE_TYPE_READ_WITH_ADDRESS;
+               --trans->bytesout;
+       }
+}
+
+static int spi_setup_opcode(struct spi_trans *trans)
+{
+       uint16_t optypes;
+       uint8_t opmenu[ctlr.menubytes];
+
+       trans->opcode = trans->out[0];
+       spi_use_out(trans, 1);
+       if (!ctlr.ichspi_lock) {
+               /* The lock is off, so just use index 0. */
+               ich_writeb(trans->opcode, ctlr.opmenu);
+               optypes = ich_readw(ctlr.optype);
+               optypes = (optypes & 0xfffc) | (trans->type & 0x3);
+               ich_writew(optypes, ctlr.optype);
+               return 0;
+       } else {
+               /* The lock is on. See if what we need is on the menu. */
+               uint8_t optype;
+               uint16_t opcode_index;
+
+               /* Write Enable is handled as atomic prefix */
+               if (trans->opcode == SPI_OPCODE_WREN)
+                       return 0;
+
+               read_reg(ctlr.opmenu, opmenu, sizeof(opmenu));
+               for (opcode_index = 0; opcode_index < ctlr.menubytes;
+                               opcode_index++) {
+                       if (opmenu[opcode_index] == trans->opcode)
+                               break;
+               }
+
+               if (opcode_index == ctlr.menubytes) {
+                       printf("ICH SPI: Opcode %x not found\n",
+                              trans->opcode);
+                       return -1;
+               }
+
+               optypes = ich_readw(ctlr.optype);
+               optype = (optypes >> (opcode_index * 2)) & 0x3;
+               if (trans->type == SPI_OPCODE_TYPE_WRITE_NO_ADDRESS &&
+                   optype == SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS &&
+                   trans->bytesout >= 3) {
+                       /* We guessed wrong earlier. Fix it up. */
+                       trans->type = optype;
+               }
+               if (optype != trans->type) {
+                       printf("ICH SPI: Transaction doesn't fit type %d\n",
+                              optype);
+                       return -1;
+               }
+               return opcode_index;
+       }
+}
+
+static int spi_setup_offset(struct spi_trans *trans)
+{
+       /* Separate the SPI address and data. */
+       switch (trans->type) {
+       case SPI_OPCODE_TYPE_READ_NO_ADDRESS:
+       case SPI_OPCODE_TYPE_WRITE_NO_ADDRESS:
+               return 0;
+       case SPI_OPCODE_TYPE_READ_WITH_ADDRESS:
+       case SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS:
+               trans->offset = ((uint32_t)trans->out[0] << 16) |
+                               ((uint32_t)trans->out[1] << 8) |
+                               ((uint32_t)trans->out[2] << 0);
+               spi_use_out(trans, 3);
+               return 1;
+       default:
+               printf("Unrecognized SPI transaction type %#x\n", trans->type);
+               return -1;
+       }
+}
+
+/*
+ * Wait for up to 6s til status register bit(s) turn 1 (in case wait_til_set
+ * below is true) or 0. In case the wait was for the bit(s) to set - write
+ * those bits back, which would cause resetting them.
+ *
+ * Return the last read status value on success or -1 on failure.
+ */
+static int ich_status_poll(u16 bitmask, int wait_til_set)
+{
+       int timeout = 600000; /* This will result in 6s */
+       u16 status = 0;
+
+       while (timeout--) {
+               status = ich_readw(ctlr.status);
+               if (wait_til_set ^ ((status & bitmask) == 0)) {
+                       if (wait_til_set)
+                               ich_writew((status & bitmask), ctlr.status);
+                       return status;
+               }
+               udelay(10);
+       }
+
+       printf("ICH SPI: SCIP timeout, read %x, expected %x\n",
+              status, bitmask);
+       return -1;
+}
+
+/*
+int spi_xfer(struct spi_slave *slave, const void *dout,
+               unsigned int bitsout, void *din, unsigned int bitsin)
+*/
+int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
+               void *din, unsigned long flags)
+{
+       struct ich_spi_slave *ich = to_ich_spi(slave);
+       uint16_t control;
+       int16_t opcode_index;
+       int with_address;
+       int status;
+       int bytes = bitlen / 8;
+       struct spi_trans *trans = &ich->trans;
+       unsigned type = flags & (SPI_XFER_BEGIN | SPI_XFER_END);
+       int using_cmd = 0;
+       /* Align read transactions to 64-byte boundaries */
+       char buff[ctlr.databytes];
+
+       /* Ee don't support writing partial bytes. */
+       if (bitlen % 8) {
+               debug("ICH SPI: Accessing partial bytes not supported\n");
+               return -1;
+       }
+
+       /* An empty end transaction can be ignored */
+       if (type == SPI_XFER_END && !dout && !din)
+               return 0;
+
+       if (type & SPI_XFER_BEGIN)
+               memset(trans, '\0', sizeof(*trans));
+
+       /* Dp we need to come back later to finish it? */
+       if (dout && type == SPI_XFER_BEGIN) {
+               if (bytes > ICH_MAX_CMD_LEN) {
+                       debug("ICH SPI: Command length limit exceeded\n");
+                       return -1;
+               }
+               memcpy(trans->cmd, dout, bytes);
+               trans->cmd_len = bytes;
+               debug("ICH SPI: Saved %d bytes\n", bytes);
+               return 0;
+       }
+
+       /*
+        * We process a 'middle' spi_xfer() call, which has no
+        * SPI_XFER_BEGIN/END, as an independent transaction as if it had
+        * an end. We therefore repeat the command. This is because ICH
+        * seems to have no support for this, or because interest (in digging
+        * out the details and creating a special case in the code) is low.
+        */
+       if (trans->cmd_len) {
+               trans->out = trans->cmd;
+               trans->bytesout = trans->cmd_len;
+               using_cmd = 1;
+               debug("ICH SPI: Using %d bytes\n", trans->cmd_len);
+       } else {
+               trans->out = dout;
+               trans->bytesout = dout ? bytes : 0;
+       }
+
+       trans->in = din;
+       trans->bytesin = din ? bytes : 0;
+
+       /* There has to always at least be an opcode. */
+       if (!trans->bytesout) {
+               debug("ICH SPI: No opcode for transfer\n");
+               return -1;
+       }
+
+       if (ich_status_poll(SPIS_SCIP, 0) == -1)
+               return -1;
+
+       ich_writew(SPIS_CDS | SPIS_FCERR, ctlr.status);
+
+       spi_setup_type(trans, using_cmd ? bytes : 0);
+       opcode_index = spi_setup_opcode(trans);
+       if (opcode_index < 0)
+               return -1;
+       with_address = spi_setup_offset(trans);
+       if (with_address < 0)
+               return -1;
+
+       if (trans->opcode == SPI_OPCODE_WREN) {
+               /*
+                * Treat Write Enable as Atomic Pre-Op if possible
+                * in order to prevent the Management Engine from
+                * issuing a transaction between WREN and DATA.
+                */
+               if (!ctlr.ichspi_lock)
+                       ich_writew(trans->opcode, ctlr.preop);
+               return 0;
+       }
+
+       if (ctlr.speed && ctlr.max_speed >= 33000000) {
+               int byte;
+
+               byte = ich_readb(ctlr.speed);
+               if (ich->speed >= 33000000)
+                       byte |= SSFC_SCF_33MHZ;
+               else
+                       byte &= ~SSFC_SCF_33MHZ;
+               ich_writeb(byte, ctlr.speed);
+       }
+
+       /* See if we have used up the command data */
+       if (using_cmd && dout && bytes) {
+               trans->out = dout;
+               trans->bytesout = bytes;
+               debug("ICH SPI: Moving to data, %d bytes\n", bytes);
+       }
+
+       /* Preset control fields */
+       control = ich_readw(ctlr.control);
+       control &= ~SSFC_RESERVED;
+       control = SPIC_SCGO | ((opcode_index & 0x07) << 4);
+
+       /* Issue atomic preop cycle if needed */
+       if (ich_readw(ctlr.preop))
+               control |= SPIC_ACS;
+
+       if (!trans->bytesout && !trans->bytesin) {
+               /* SPI addresses are 24 bit only */
+               if (with_address)
+                       ich_writel(trans->offset & 0x00FFFFFF, ctlr.addr);
+
+               /*
+                * This is a 'no data' command (like Write Enable), its
+                * bitesout size was 1, decremented to zero while executing
+                * spi_setup_opcode() above. Tell the chip to send the
+                * command.
+                */
+               ich_writew(control, ctlr.control);
+
+               /* wait for the result */
+               status = ich_status_poll(SPIS_CDS | SPIS_FCERR, 1);
+               if (status == -1)
+                       return -1;
+
+               if (status & SPIS_FCERR) {
+                       debug("ICH SPI: Command transaction error\n");
+                       return -1;
+               }
+
+               return 0;
+       }
+
+       /*
+        * Check if this is a write command atempting to transfer more bytes
+        * than the controller can handle. Iterations for writes are not
+        * supported here because each SPI write command needs to be preceded
+        * and followed by other SPI commands, and this sequence is controlled
+        * by the SPI chip driver.
+        */
+       if (trans->bytesout > ctlr.databytes) {
+               debug("ICH SPI: Too much to write. This should be prevented by the driver's max_write_size?\n");
+               return -1;
+       }
+
+       /*
+        * Read or write up to databytes bytes at a time until everything has
+        * been sent.
+        */
+       while (trans->bytesout || trans->bytesin) {
+               uint32_t data_length;
+               uint32_t aligned_offset;
+               uint32_t diff;
+
+               aligned_offset = trans->offset & ~(ctlr.databytes - 1);
+               diff = trans->offset - aligned_offset;
+
+               /* SPI addresses are 24 bit only */
+               ich_writel(aligned_offset & 0x00FFFFFF, ctlr.addr);
+
+               if (trans->bytesout)
+                       data_length = min(trans->bytesout, ctlr.databytes);
+               else
+                       data_length = min(trans->bytesin, ctlr.databytes);
+
+               /* Program data into FDATA0 to N */
+               if (trans->bytesout) {
+                       write_reg(trans->out, ctlr.data, data_length);
+                       spi_use_out(trans, data_length);
+                       if (with_address)
+                               trans->offset += data_length;
+               }
+
+               /* Add proper control fields' values */
+               control &= ~((ctlr.databytes - 1) << 8);
+               control |= SPIC_DS;
+               control |= (data_length - 1) << 8;
+
+               /* write it */
+               ich_writew(control, ctlr.control);
+
+               /* Wait for Cycle Done Status or Flash Cycle Error. */
+               status = ich_status_poll(SPIS_CDS | SPIS_FCERR, 1);
+               if (status == -1)
+                       return -1;
+
+               if (status & SPIS_FCERR) {
+                       debug("ICH SPI: Data transaction error\n");
+                       return -1;
+               }
+
+               if (trans->bytesin) {
+                       if (diff) {
+                               data_length -= diff;
+                               read_reg(ctlr.data, buff, ctlr.databytes);
+                               memcpy(trans->in, buff + diff, data_length);
+                       } else {
+                               read_reg(ctlr.data, trans->in, data_length);
+                       }
+                       spi_use_in(trans, data_length);
+                       if (with_address)
+                               trans->offset += data_length;
+               }
+       }
+
+       /* Clear atomic preop now that xfer is done */
+       ich_writew(0, ctlr.preop);
+
+       return 0;
+}
+
+
+/*
+ * This uses the SPI controller from the Intel Cougar Point and Panther Point
+ * PCH to write-protect portions of the SPI flash until reboot. The changes
+ * don't actually take effect until the HSFS[FLOCKDN] bit is set, but that's
+ * done elsewhere.
+ */
+int spi_write_protect_region(uint32_t lower_limit, uint32_t length, int hint)
+{
+       uint32_t tmplong;
+       uint32_t upper_limit;
+
+       if (!ctlr.pr) {
+               printf("%s: operation not supported on this chipset\n",
+                      __func__);
+               return -1;
+       }
+
+       if (length == 0 ||
+           lower_limit > (0xFFFFFFFFUL - length) + 1 ||
+           hint < 0 || hint > 4) {
+               printf("%s(0x%x, 0x%x, %d): invalid args\n", __func__,
+                      lower_limit, length, hint);
+               return -1;
+       }
+
+       upper_limit = lower_limit + length - 1;
+
+       /*
+        * Determine bits to write, as follows:
+        *  31     Write-protection enable (includes erase operation)
+        *  30:29  reserved
+        *  28:16  Upper Limit (FLA address bits 24:12, with 11:0 == 0xfff)
+        *  15     Read-protection enable
+        *  14:13  reserved
+        *  12:0   Lower Limit (FLA address bits 24:12, with 11:0 == 0x000)
+        */
+       tmplong = 0x80000000 |
+               ((upper_limit & 0x01fff000) << 4) |
+               ((lower_limit & 0x01fff000) >> 12);
+
+       printf("%s: writing 0x%08x to %p\n", __func__, tmplong,
+              &ctlr.pr[hint]);
+       ctlr.pr[hint] = tmplong;
+
+       return 0;
+}