[PATCH] i2c: adds support for i2c bus on Freescale CPM1/CPM2 controllers

Jochen Friedrich
2008-05-21T10:43:50Z

This driver uses the port of 2.4 code from Vitaly Bordug
<vitb@kernel.crashing.org> and the actual algorithm used by the i2c
driver of the DBox code on cvs.tuxboc.org from Felix Domke
(tmbinc@gmx.net) and Gillem (htoa@gmx.net) converted to an
of_platform_driver. Tested on CPM1 (MPC823 on dbox2 hardware) and
CPM2 (MPC8272).

Signed-off-by: Jochen Friedrich <jochen@scram.de>
---
drivers/i2c/busses/Kconfig | 10 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-cpm.c | 745 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 756 insertions(+), 0 deletions(-)
create mode 100644 drivers/i2c/busses/i2c-cpm.c

Changes since last version:
- fixed copy and paste bug (I2COM_MASTER -> I2COM_START)
- changed dev_err() to dev_dbg() for NACK
- changed dev_dbg() to dev_err() for Timeout
- added explanation for brg formular
- added "bus-frequency" OF attribute to be able to override i2c clock
- support for numbered adapter (it was already documented in
my booting-without-of patch but not yet implemented)
- finally changed i2c "pseudo address" 0xfe to 0x7f << 1
- get rid of the "fsl,cpm-i2c" name. This logic was screwed
- fixed the error patch for request_irq failure
- s/IIC/I2C/g
- fixed error output "read timeout" -> "transfer timeout"

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 48438cc..c627b94 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -117,6 +117,16 @@ config I2C_BLACKFIN_TWI_CLK_KHZ
help
The unit of the TWI clock is kHz.

+config I2C_CPM
+ tristate "Freescale CPM1 or CPM2 (MPC8xx/826x)"
+ depends on (CPM1 || CPM2) && OF_I2C
+ help
+ This supports the use of the I2C interface on Freescale
+ processors with CPM1 or CPM2.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-cpm.
+
config I2C_DAVINCI
tristate "DaVinci I2C driver"
depends on ARCH_DAVINCI
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index e8c882a..1ccd5ba 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -11,6 +11,7 @@ obj-$(CONFIG_I2C_AMD8111) += i2c-amd8111.o
obj-$(CONFIG_I2C_AT91) += i2c-at91.o
obj-$(CONFIG_I2C_AU1550) += i2c-au1550.o
obj-$(CONFIG_I2C_BLACKFIN_TWI) += i2c-bfin-twi.o
+obj-$(CONFIG_I2C_CPM) += i2c-cpm.o
obj-$(CONFIG_I2C_DAVINCI) += i2c-davinci.o
obj-$(CONFIG_I2C_ELEKTOR) += i2c-elektor.o
obj-$(CONFIG_I2C_GPIO) += i2c-gpio.o
diff --git a/drivers/i2c/busses/i2c-cpm.c b/drivers/i2c/busses/i2c-cpm.c
new file mode 100644
index 0000000..305159c
--- /dev/null
+++ b/drivers/i2c/busses/i2c-cpm.c
@@ -0,0 +1,745 @@
+/*
+ * Freescale CPM1/CPM2 I2C interface.
+ * Copyright (c) 1999 Dan Malek (dmalek@jlc.net).
+ *
+ * moved into proper i2c interface;
+ * Brad Parker (brad@heeltoe.com)
+ *
+ * Parts from dbox2_i2c.c (cvs.tuxbox.org)
+ * (C) 2000-2001 Felix Domke (tmbinc@gmx.net), Gillem (htoa@gmx.net)
+ *
+ * (C) 2007 Montavista Software, Inc.
+ * Vitaly Bordug <vitb@kernel.crashing.org>
+ *
+ * Converted to of_platform_device. Renamed to i2c-cpm.c.
+ * (C) 2007,2008 Jochen Friedrich <jochen@scram.de>
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/errno.h>
+#include <linux/stddef.h>
+#include <linux/i2c.h>
+#include <linux/io.h>
+#include <linux/dma-mapping.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/of_i2c.h>
+#include <sysdev/fsl_soc.h>
+#include <asm/cpm.h>
+
+/* Try to define this if you have an older CPU (earlier than rev D4) */
+/* However, better use a GPIO based bitbang driver in this case :/ */
+#undef I2C_CHIP_ERRATA
+
+#define CPM_MAX_READ 513
+#define CPM_MAXBD 4
+
+#define I2C_EB (0x10) /* Big endian mode */
+#define I2C_EB_CPM2 (0x30) /* Big endian mode, memory snoop */
+
+#define DPRAM_BASE ((u8 __iomem __force *)cpm_muram_addr(0))
+
+/* I2C parameter RAM. */
+struct i2c_ram {
+ ushort rbase; /* Rx Buffer descriptor base address */
+ ushort tbase; /* Tx Buffer descriptor base address */
+ u_char rfcr; /* Rx function code */
+ u_char tfcr; /* Tx function code */
+ ushort mrblr; /* Max receive buffer length */
+ uint rstate; /* Internal */
+ uint rdp; /* Internal */
+ ushort rbptr; /* Rx Buffer descriptor pointer */
+ ushort rbc; /* Internal */
+ uint rxtmp; /* Internal */
+ uint tstate; /* Internal */
+ uint tdp; /* Internal */
+ ushort tbptr; /* Tx Buffer descriptor pointer */
+ ushort tbc; /* Internal */
+ uint txtmp; /* Internal */
+ char res1[4]; /* Reserved */
+ ushort rpbase; /* Relocation pointer */
+ char res2[2]; /* Reserved */
+};
+
+#define I2COM_START 0x80
+#define I2COM_MASTER 0x01
+#define I2CER_TXE 0x10
+#define I2CER_BUSY 0x04
+#define I2CER_TXB 0x02
+#define I2CER_RXB 0x01
+#define I2MOD_EN 0x01
+
+/* I2C Registers */
+struct i2c_reg {
+ u8 i2mod;
+ u8 res1[3];
+ u8 i2add;
+ u8 res2[3];
+ u8 i2brg;
+ u8 res3[3];
+ u8 i2com;
+ u8 res4[3];
+ u8 i2cer;
+ u8 res5[3];
+ u8 i2cmr;
+};
+
+struct cpm_i2c {
+ char *base;
+ struct of_device *ofdev;
+ struct i2c_adapter adap;
+ uint dp_addr;
+ int version; /* CPM1=1, CPM2=2 */
+ int irq;
+ int cp_command;
+ int freq;
+ struct i2c_reg __iomem *i2c_reg;
+ struct i2c_ram __iomem *i2c_ram;
+ u16 i2c_addr;
+ wait_queue_head_t i2c_wait;
+ cbd_t __iomem *tbase;
+ cbd_t __iomem *rbase;
+ u_char *txbuf[CPM_MAXBD];
+ u_char *rxbuf[CPM_MAXBD];
+ u32 txdma[CPM_MAXBD];
+ u32 rxdma[CPM_MAXBD];
+};
+
+static irqreturn_t cpm_i2c_interrupt(int irq, void *dev_id)
+{
+ struct cpm_i2c *cpm;
+ struct i2c_reg __iomem *i2c_reg;
+ struct i2c_adapter *adap = dev_id;
+ int i;
+
+ cpm = i2c_get_adapdata(dev_id);
+ i2c_reg = cpm->i2c_reg;
+
+ /* Clear interrupt. */
+ i = in_8(&i2c_reg->i2cer);
+ out_8(&i2c_reg->i2cer, i);
+
+ dev_dbg(&adap->dev, "Interrupt: %x\n", i);
+
+ wake_up_interruptible(&cpm->i2c_wait);
+
+ return i ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static void cpm_reset_i2c_params(struct cpm_i2c *cpm)
+{
+ struct i2c_ram __iomem *i2c_ram = cpm->i2c_ram;
+
+ /* Set up the I2C parameters in the parameter ram. */
+ out_be16(&i2c_ram->tbase, (u8 __iomem *)cpm->tbase - DPRAM_BASE);
+ out_be16(&i2c_ram->rbase, (u8 __iomem *)cpm->rbase - DPRAM_BASE);
+
+ if (cpm->version == 1) {
+ out_8(&i2c_ram->tfcr, I2C_EB);
+ out_8(&i2c_ram->rfcr, I2C_EB);
+ } else {
+ out_8(&i2c_ram->tfcr, I2C_EB_CPM2);
+ out_8(&i2c_ram->rfcr, I2C_EB_CPM2);
+ }
+
+ out_be16(&i2c_ram->mrblr, CPM_MAX_READ);
+
+ out_be32(&i2c_ram->rstate, 0);
+ out_be32(&i2c_ram->rdp, 0);
+ out_be16(&i2c_ram->rbptr, 0);
+ out_be16(&i2c_ram->rbc, 0);
+ out_be32(&i2c_ram->rxtmp, 0);
+ out_be32(&i2c_ram->tstate, 0);
+ out_be32(&i2c_ram->tdp, 0);
+ out_be16(&i2c_ram->tbptr, 0);
+ out_be16(&i2c_ram->tbc, 0);
+ out_be32(&i2c_ram->txtmp, 0);
+}
+
+static void cpm_i2c_force_close(struct i2c_adapter *adap)
+{
+ struct cpm_i2c *cpm = i2c_get_adapdata(adap);
+ struct i2c_reg __iomem *i2c_reg = cpm->i2c_reg;
+
+ dev_dbg(&adap->dev, "cpm_i2c_force_close()\n");
+
+ cpm_command(cpm->cp_command, CPM_CR_CLOSE_RX_BD);
+
+ out_8(&i2c_reg->i2cmr, 0x00); /* Disable all interrupts */
+ out_8(&i2c_reg->i2cer, 0xff);
+}
+
+static void cpm_i2c_parse_message(struct i2c_adapter *adap,
+ struct i2c_msg *pmsg, int num, int tx, int rx)
+{
+ cbd_t __iomem *tbdf;
+ cbd_t __iomem *rbdf;
+ u_char addr;
+ u_char *tb;
+ u_char *rb;
+ struct cpm_i2c *cpm = i2c_get_adapdata(adap);
+
+ tbdf = cpm->tbase + tx;
+ rbdf = cpm->rbase + rx;
+
+ addr = pmsg->addr << 1;
+ if (pmsg->flags & I2C_M_RD)
+ addr |= 1;
+
+ tb = cpm->txbuf[tx];
+ rb = cpm->rxbuf[rx];
+
+ /* Align read buffer */
+ rb = (u_char *) (((ulong) rb + 1) & ~1);
+
+ tb[0] = addr; /* Device address byte w/rw flag */
+
+ out_be16(&tbdf->cbd_datlen, pmsg->len + 1);
+ out_be16(&tbdf->cbd_sc, 0);
+
+ if (!(pmsg->flags & I2C_M_NOSTART))
+ setbits16(&tbdf->cbd_sc, BD_I2C_START);
+
+ if (tx + 1 == num)
+ setbits16(&tbdf->cbd_sc, BD_SC_LAST | BD_SC_WRAP);
+
+ if (pmsg->flags & I2C_M_RD) {
+ /*
+ * To read, we need an empty buffer of the proper length.
+ * All that is used is the first byte for address, the remainder
+ * is just used for timing (and doesn't really have to exist).
+ */
+
+ dev_dbg(&adap->dev, "cpm_i2c_read(abyte=0x%x)\n", addr);
+
+ out_be16(&rbdf->cbd_datlen, 0);
+ out_be16(&rbdf->cbd_sc, BD_SC_EMPTY | BD_SC_INTRPT);
+
+ if (rx + 1 == CPM_MAXBD)
+ setbits16(&rbdf->cbd_sc, BD_SC_WRAP);
+
+ eieio();
+ setbits16(&tbdf->cbd_sc, BD_SC_READY);
+ } else {
+ dev_dbg(&adap->dev, "cpm_iic_write(abyte=0x%x)\n", addr);
+
+ memcpy(tb+1, pmsg->buf, pmsg->len);
+
+ eieio();
+ setbits16(&tbdf->cbd_sc, BD_SC_READY | BD_SC_INTRPT);
+ }
+}
+
+static int cpm_i2c_check_message(struct i2c_adapter *adap,
+ struct i2c_msg *pmsg, int tx, int rx)
+{
+ cbd_t __iomem *tbdf;
+ cbd_t __iomem *rbdf;
+ u_char *tb;
+ u_char *rb;
+ struct cpm_i2c *cpm = i2c_get_adapdata(adap);
+
+ tbdf = cpm->tbase + tx;
+ rbdf = cpm->rbase + rx;
+
+ tb = cpm->txbuf[tx];
+ rb = cpm->rxbuf[rx];
+
+ /* Align read buffer */
+ rb = (u_char *) (((uint) rb + 1) & ~1);
+
+ eieio();
+ if (pmsg->flags & I2C_M_RD) {
+ dev_dbg(&adap->dev, "tx sc 0x%04x, rx sc 0x%04x\n",
+ in_be16(&tbdf->cbd_sc), in_be16(&rbdf->cbd_sc));
+
+ if (in_be16(&tbdf->cbd_sc) & BD_SC_NAK) {
+ dev_dbg(&adap->dev, "I2C read; No ack\n");
+ return -ENXIO;
+ }
+ if (in_be16(&rbdf->cbd_sc) & BD_SC_EMPTY) {
+ dev_err(&adap->dev,
+ "I2C read; complete but rbuf empty\n");
+ return -EREMOTEIO;
+ }
+ if (in_be16(&rbdf->cbd_sc) & BD_SC_OV) {
+ dev_err(&adap->dev, "I2C read; Overrun\n");
+ return -EREMOTEIO;
+ }
+ memcpy(pmsg->buf, rb, pmsg->len);
+ } else {
+ dev_dbg(&adap->dev, "tx sc %d 0x%04x\n", tx,
+ in_be16(&tbdf->cbd_sc));
+
+ if (in_be16(&tbdf->cbd_sc) & BD_SC_NAK) {
+ dev_dbg(&adap->dev, "I2C write; No ack\n");
+ return -ENXIO;
+ }
+ if (in_be16(&tbdf->cbd_sc) & BD_SC_UN) {
+ dev_err(&adap->dev, "I2C write; Underrun\n");
+ return -EIO;
+ }
+ if (in_be16(&tbdf->cbd_sc) & BD_SC_CL) {
+ dev_err(&adap->dev, "I2C write; Collision\n");
+ return -EIO;
+ }
+ }
+ return 0;
+}
+
+static int cpm_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+ struct cpm_i2c *cpm = i2c_get_adapdata(adap);
+ struct i2c_reg __iomem *i2c_reg = cpm->i2c_reg;
+ struct i2c_ram __iomem *i2c_ram = cpm->i2c_ram;
+ struct i2c_msg *pmsg;
+ int ret, i;
+ int tptr;
+ int rptr;
+ cbd_t __iomem *tbdf;
+ cbd_t __iomem *rbdf;
+
+ if (num > CPM_MAXBD)
+ return -EINVAL;
+
+ /* Check if we have any oversized READ requests */
+ for (i = 0; i < num; i++) {
+ pmsg = &msgs[i];
+ if (pmsg->len >= CPM_MAX_READ)
+ return -EINVAL;
+ }
+
+ /* Reset to use first buffer */
+ out_be16(&i2c_ram->rbptr, in_be16(&i2c_ram->rbase));
+ out_be16(&i2c_ram->tbptr, in_be16(&i2c_ram->tbase));
+
+ tbdf = cpm->tbase;
+ rbdf = cpm->rbase;
+
+ tptr = 0;
+ rptr = 0;
+
+ while (tptr < num) {
+ pmsg = &msgs[tptr];
+ dev_dbg(&adap->dev, "R: %d T: %d\n", rptr, tptr);
+
+ cpm_i2c_parse_message(adap, pmsg, num, tptr, rptr);
+ if (pmsg->flags & I2C_M_RD)
+ rptr++;
+ tptr++;
+ }
+ /* Start transfer now */
+ /* Enable RX/TX/Error interupts */
+ out_8(&i2c_reg->i2cmr, I2CER_BUSY | I2CER_TXB | I2CER_RXB);
+ out_8(&i2c_reg->i2cer, 0xff); /* Clear interrupt status */
+ /* Chip bug, set enable here */
+ setbits8(&i2c_reg->i2mod, I2MOD_EN); /* Enable */
+ /* Begin transmission */
+ setbits8(&i2c_reg->i2com, I2COM_START);
+
+ tptr = 0;
+ rptr = 0;
+
+ while (tptr < num) {
+ /* Check for outstanding messages */
+ dev_dbg(&adap->dev, "test ready.\n");
+ pmsg = &msgs[tptr];
+ if (pmsg->flags & I2C_M_RD)
+ ret = wait_event_interruptible_timeout(cpm->i2c_wait,
+ !(in_be16(&rbdf[rptr].cbd_sc) & BD_SC_EMPTY),
+ 1 * HZ);
+ else
+ ret = wait_event_interruptible_timeout(cpm->i2c_wait,
+ !(in_be16(&tbdf[tptr].cbd_sc) & BD_SC_READY),
+ 1 * HZ);
+ if (ret == 0) {
+ ret = -EREMOTEIO;
+ dev_err(&adap->dev, "I2C transfer: timeout\n");
+ goto out_err;
+ }
+ if (ret > 0) {
+ dev_dbg(&adap->dev, "ready.\n");
+ ret = cpm_i2c_check_message(adap, pmsg, tptr, rptr);
+ tptr++;
+ if (pmsg->flags & I2C_M_RD)
+ rptr++;
+ if (ret)
+ goto out_err;
+ }
+ }
+#ifdef I2C_CHIP_ERRATA
+ /*
+ * Chip errata, clear enable. This is not needed on rev D4 CPUs.
+ * Disabling I2C too early may cause too short stop condition
+ */
+ udelay(4);
+ clrbits8(&i2c_reg->i2mod, I2MOD_EN);
+#endif
+ return (num);
+
+out_err:
+ cpm_i2c_force_close(adap);
+#ifdef I2C_CHIP_ERRATA
+ /*
+ * Chip errata, clear enable. This is not needed on rev D4 CPUs.
+ */
+ clrbits8(&i2c_reg->i2mod, I2MOD_EN);
+#endif
+ return ret;
+}
+
+static u32 cpm_i2c_func(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
+}
+
+/* -----exported algorithm data: ------------------------------------- */
+
+static const struct i2c_algorithm cpm_i2c_algo = {
+ .master_xfer = cpm_i2c_xfer,
+ .functionality = cpm_i2c_func,
+};
+
+static const struct i2c_adapter cpm_ops = {
+ .owner = THIS_MODULE,
+ .name = "i2c-cpm",
+ .algo = &cpm_i2c_algo,
+ .class = I2C_CLASS_HWMON,
+};
+
+static int __devinit cpm_i2c_setup(struct cpm_i2c *cpm)
+{
+ struct of_device *ofdev = cpm->ofdev;
+ const u32 *data;
+ int len, ret, i;
+ void __iomem *i2c_base;
+ cbd_t __iomem *tbdf;
+ cbd_t __iomem *rbdf;
+ unsigned char brg;
+
+ dev_dbg(&cpm->ofdev->dev, "cpm_i2c_setup()\n");
+
+ init_waitqueue_head(&cpm->i2c_wait);
+
+ cpm->irq = of_irq_to_resource(ofdev->node, 0, NULL);
+ if (cpm->irq == NO_IRQ)
+ return -EINVAL;
+
+ /* Install interrupt handler. */
+ ret = request_irq(cpm->irq, cpm_i2c_interrupt, 0, "cpm_i2c",
+ &cpm->adap);
+ if (ret)
+ return ret;
+
+ /* I2C parameter RAM */
+ i2c_base = of_iomap(ofdev->node, 1);
+ if (i2c_base == NULL) {
+ ret = -EINVAL;
+ goto out_irq;
+ }
+
+ if (of_device_is_compatible(ofdev->node, "fsl,cpm1-i2c")) {
+
+ /* Check for and use a microcode relocation patch. */
+ cpm->i2c_ram = i2c_base;
+ cpm->i2c_addr = in_be16(&cpm->i2c_ram->rpbase);
+
+ /*
+ * Maybe should use cpm_muram_alloc instead of hardcoding
+ * this in micropatch.c
+ */
+ if (cpm->i2c_addr) {
+ cpm->i2c_ram = cpm_muram_addr(cpm->i2c_addr);
+ iounmap(i2c_base);
+ }
+
+ cpm->version = 1;
+
+ } else if (of_device_is_compatible(ofdev->node, "fsl,cpm2-i2c")) {
+ cpm->i2c_addr = cpm_muram_alloc(sizeof(struct i2c_ram), 64);
+ cpm->i2c_ram = cpm_muram_addr(cpm->i2c_addr);
+ out_be16(i2c_base, cpm->i2c_addr);
+ iounmap(i2c_base);
+
+ cpm->version = 2;
+
+ } else {
+ iounmap(i2c_base);
+ ret = -EINVAL;
+ goto out_irq;
+ }
+
+ /* I2C control/status registers */
+ cpm->i2c_reg = of_iomap(ofdev->node, 0);
+ if (cpm->i2c_reg == NULL) {
+ ret = -EINVAL;
+ goto out_ram;
+ }
+
+ data = of_get_property(ofdev->node, "fsl,cpm-command", &len);
+ if (!data || len != 4) {
+ ret = -EINVAL;
+ goto out_reg;
+ }
+ cpm->cp_command = *data;
+
+ data = of_get_property(ofdev->node, "linux,i2c-class", &len);
+ if (data && len == 4)
+ cpm->adap.class = *data;
+
+ data = of_get_property(ofdev->node, "bus-frequency", &len);
+ if (data && len == 4)
+ cpm->freq = *data;
+ else
+ cpm->freq = 60000; /* use 60kHz i2c bus frequency by default */
+
+ /*
+ * Allocate space for CPM_MAXBD transmit and receive buffer
+ * descriptors in the DP ram.
+ */
+ cpm->dp_addr = cpm_muram_alloc(sizeof(cbd_t) * 2 * CPM_MAXBD, 8);
+ if (!cpm->dp_addr) {
+ ret = -ENOMEM;
+ goto out_reg;
+ }
+
+ cpm->tbase = cpm_muram_addr(cpm->dp_addr);
+ cpm->rbase = cpm_muram_addr(cpm->dp_addr + sizeof(cbd_t) * CPM_MAXBD);
+
+ /* Allocate TX and RX buffers */
+
+ tbdf = cpm->tbase;
+ rbdf = cpm->rbase;
+
+ for (i = 0; i < CPM_MAXBD; i++) {
+ cpm->rxbuf[i] = dma_alloc_coherent(
+ NULL, CPM_MAX_READ + 1, &cpm->rxdma[i], GFP_KERNEL);
+ if (!cpm->rxbuf[i]) {
+ ret = -ENOMEM;
+ goto out_muram;
+ }
+ out_be32(&rbdf[i].cbd_bufaddr, ((cpm->rxdma[i] + 1) & ~1));
+
+ cpm->txbuf[i] = (unsigned char *)dma_alloc_coherent(
+ NULL, CPM_MAX_READ + 1, &cpm->txdma[i], GFP_KERNEL);
+ if (!cpm->txbuf[i]) {
+ ret = -ENOMEM;
+ goto out_muram;
+ }
+ out_be32(&tbdf[i].cbd_bufaddr, cpm->txdma[i]);
+ }
+
+ /* Initialize Tx/Rx parameters. */
+
+ cpm_reset_i2c_params(cpm);
+
+ dev_dbg(&cpm->ofdev->dev, "i2c_ram %p, i2c_addr 0x%04x\n",
+ cpm->i2c_ram, cpm->i2c_addr);
+ dev_dbg(&cpm->ofdev->dev, "tbase 0x%04x, rbase 0x%04x\n",
+ (u8 __iomem *)cpm->tbase - DPRAM_BASE,
+ (u8 __iomem *)cpm->rbase - DPRAM_BASE);
+
+ cpm_command(cpm->cp_command, CPM_CR_INIT_TRX);
+
+ /*
+ * Select an invalid address. Just make sure we don't use loopback mode
+ */
+ out_8(&cpm->i2c_reg->i2add, 0x7f << 1);
+
+ /*
+ * PDIV is set to 00 in i2mod, so brgclk/32 is used as input to the
+ * i2c baud rate generator. This is devided by 2 x (DIV + 3) to get
+ * the actual i2c bus frequency.
+ */
+ brg = get_brgfreq() / (32 * 2 * cpm->freq) - 3;
+ out_8(&cpm->i2c_reg->i2brg, brg);
+
+ out_8(&cpm->i2c_reg->i2mod, 0x00);
+ out_8(&cpm->i2c_reg->i2com, I2COM_MASTER); /* Master mode */
+
+ /* Disable interrupts. */
+ out_8(&cpm->i2c_reg->i2cmr, 0);
+ out_8(&cpm->i2c_reg->i2cer, 0xff);
+
+ return 0;
+
+out_muram:
+ for (i = 0; i < CPM_MAXBD; i++) {
+ if (cpm->rxbuf[i])
+ dma_free_coherent(NULL, CPM_MAX_READ + 1,
+ cpm->rxbuf[i], cpm->rxdma[i]);
+ if (cpm->txbuf[i])
+ dma_free_coherent(NULL, CPM_MAX_READ + 1,
+ cpm->txbuf[i], cpm->txdma[i]);
+ }
+ cpm_muram_free(cpm->dp_addr);
+out_reg:
+ iounmap(cpm->i2c_reg);
+out_ram:
+ if ((cpm->version == 1) && (!cpm->i2c_addr))
+ iounmap(cpm->i2c_ram);
+ if (cpm->version == 2)
+ cpm_muram_free(cpm->i2c_addr);
+out_irq:
+ free_irq(cpm->irq, &cpm->adap);
+ return ret;
+}
+
+static void cpm_i2c_shutdown(struct cpm_i2c *cpm)
+{
+ int i;
+
+ /* Shut down I2C. */
+ clrbits8(&cpm->i2c_reg->i2mod, I2MOD_EN);
+
+ /* Disable interrupts */
+ out_8(&cpm->i2c_reg->i2cmr, 0);
+ out_8(&cpm->i2c_reg->i2cer, 0xff);
+
+ free_irq(cpm->irq, &cpm->adap);
+
+ /* Free all memory */
+ for (i = 0; i < CPM_MAXBD; i++) {
+ dma_free_coherent(NULL, CPM_MAX_READ + 1,
+ cpm->rxbuf[i], cpm->rxdma[i]);
+ dma_free_coherent(NULL, CPM_MAX_READ + 1,
+ cpm->txbuf[i], cpm->txdma[i]);
+ }
+
+ cpm_muram_free(cpm->dp_addr);
+ iounmap(cpm->i2c_reg);
+
+ if ((cpm->version == 1) && (!cpm->i2c_addr))
+ iounmap(cpm->i2c_ram);
+ if (cpm->version == 2)
+ cpm_muram_free(cpm->i2c_addr);
+}
+
+static int __devinit cpm_i2c_probe(struct of_device *ofdev,
+ const struct of_device_id *match)
+{
+ int result, len;
+ struct cpm_i2c *cpm;
+ const u32 *data;
+
+ cpm = kzalloc(sizeof(struct cpm_i2c), GFP_KERNEL);
+ if (!cpm)
+ return -ENOMEM;
+
+ cpm->ofdev = ofdev;
+
+ dev_set_drvdata(&ofdev->dev, cpm);
+
+ cpm->adap = cpm_ops;
+ i2c_set_adapdata(&cpm->adap, cpm);
+ cpm->adap.dev.parent = &ofdev->dev;
+
+ result = cpm_i2c_setup(cpm);
+ if (result) {
+ dev_err(&ofdev->dev, "Unable to init hardware\n");
+ goto out_free;
+ }
+
+ /* register new adapter to i2c module... */
+
+ data = of_get_property(ofdev->node, "linux,i2c-index", &len);
+ if (data && len == 4) {
+ cpm->adap.nr = *data;
+ result = i2c_add_numbered_adapter(&cpm->adap);
+ } else
+ result = i2c_add_adapter(&cpm->adap);
+
+ if (result < 0) {
+ dev_err(&ofdev->dev, "Unable to register with I2C\n");
+ goto out_shut;
+ }
+
+ dev_dbg(&ofdev->dev, "hw routines for %s registered.\n",
+ cpm->adap.name);
+
+ /*
+ * register OF I2C devices
+ */
+ of_register_i2c_devices(&cpm->adap, ofdev->node);
+
+ return 0;
+out_shut:
+ cpm_i2c_shutdown(cpm);
+out_free:
+ dev_set_drvdata(&ofdev->dev, NULL);
+ kfree(cpm);
+
+ return result;
+}
+
+static int __devexit cpm_i2c_remove(struct of_device *ofdev)
+{
+ struct cpm_i2c *cpm = dev_get_drvdata(&ofdev->dev);
+
+ i2c_del_adapter(&cpm->adap);
+
+ cpm_i2c_shutdown(cpm);
+
+ dev_set_drvdata(&ofdev->dev, NULL);
+ kfree(cpm);
+
+ return 0;
+}
+
+static const struct of_device_id cpm_i2c_match[] = {
+ {
+ .compatible = "fsl,cpm1-i2c",
+ },
+ {
+ .compatible = "fsl,cpm2-i2c",
+ },
+ {},
+};
+
+MODULE_DEVICE_TABLE(of, cpm_i2c_match);
+
+static struct of_platform_driver cpm_i2c_driver = {
+ .match_table = cpm_i2c_match,
+ .probe = cpm_i2c_probe,
+ .remove = __devexit_p(cpm_i2c_remove),
+ .driver = {
+ .name = "fsl-i2c-cpm",
+ .owner = THIS_MODULE,
+ }
+};
+
+static int __init cpm_i2c_init(void)
+{
+ return of_register_platform_driver(&cpm_i2c_driver);
+}
+
+static void __exit cpm_i2c_exit(void)
+{
+ of_unregister_platform_driver(&cpm_i2c_driver);
+}
+
+module_init(cpm_i2c_init);
+module_exit(cpm_i2c_exit);
+
+MODULE_AUTHOR("Jochen Friedrich <jochen@scram.de>");
+MODULE_DESCRIPTION("I2C-Bus adapter routines for CPM boards");
+MODULE_LICENSE("GPL");
--
1.5.5.1