Add support for on chip I2C bus controller on Netlogic XLR/XLS family
of MIPS64 SoCs. The changes are:
Kconfig/Makefile: add CONFIG_I2C_XLR option
busses/i2c-xlr.c : driver for Netlogic XLR/XLS on-chip I2C controller
Signed-off-by: Ganesan Ramalingam <ganesanr@xxxxxxxxxxxxxxxxx>
Signed-off-by: Jayachandran C <jayachandranc@xxxxxxxxxxxxxxxxx>
---
[Posting this again, comments and suggestions welcome]
Changes since v2:
- Remove platform related code changes to a different patch that will be
submitted later thru linux-mips
Changes since v1:
- Use master_xfer in place of smbus_xfer
- Fixes for the comments from Ben Dooks and Mark Brown
drivers/i2c/busses/Kconfig | 11 ++
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-xlr.c | 303 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 315 insertions(+), 0 deletions(-)
create mode 100644 drivers/i2c/busses/i2c-xlr.c
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 646068e..4ac63f5 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -309,6 +309,17 @@ config I2C_AU1550
This driver can also be built as a module. If so, the module
will be called i2c-au1550.
+config I2C_XLR
+ tristate "XLR I2C support"
+ depends on CPU_XLR
+ help
+ This driver enables support for the on-chip I2C interface of
+ the Netlogic XLR/XLS MIPS processors.
+
+ Say yes to this option if you have a Netlogic XLR/XLS based
+ board and you need to access the I2C devices (typically the
+ RTC, sensors, EEPROM) connected to this interface.
+
config I2C_BLACKFIN_TWI
tristate "Blackfin TWI I2C support"
depends on BLACKFIN
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index e6cf294..14e7a76 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -65,6 +65,7 @@ obj-$(CONFIG_I2C_TEGRA) += i2c-tegra.o
obj-$(CONFIG_I2C_VERSATILE) += i2c-versatile.o
obj-$(CONFIG_I2C_OCTEON) += i2c-octeon.o
obj-$(CONFIG_I2C_XILINX) += i2c-xiic.o
+obj-$(CONFIG_I2C_XLR) += i2c-xlr.o
obj-$(CONFIG_I2C_EG20T) += i2c-eg20t.o
# External I2C/SMBus adapter drivers
diff --git a/drivers/i2c/busses/i2c-xlr.c b/drivers/i2c/busses/i2c-xlr.c
new file mode 100644
index 0000000..d433b2f
--- /dev/null
+++ b/drivers/i2c/busses/i2c-xlr.c
@@ -0,0 +1,303 @@
+/*
+ * Copyright 2011, Netlogic Microsystems Inc.
+ * Copyright 2004, Matt Porter <mporter@xxxxxxxxxxxxxxxxxxx>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <asm/netlogic/xlr/iomap.h>
+
+/* XLR I2C REGISTERS */
+#define XLR_I2C_CFG 0x00
+#define XLR_I2C_CLKDIV 0x01
+#define XLR_I2C_DEVADDR 0x02
+#define XLR_I2C_ADDR 0x03
+#define XLR_I2C_DATAOUT 0x04
+#define XLR_I2C_DATAIN 0x05
+#define XLR_I2C_STATUS 0x06
+#define XLR_I2C_STARTXFR 0x07
+#define XLR_I2C_BYTECNT 0x08
+#define XLR_I2C_HDSTATIM 0x09
+
+/* XLR I2C REGISTERS FLAGS */
+#define XLR_I2C_BUS_BUSY 0x01
+#define XLR_I2C_SDOEMPTY 0x02
+#define XLR_I2C_RXRDY 0x04
+#define XLR_I2C_ACK_ERR 0x08
+#define XLR_I2C_ARB_STARTERR 0x30
+
+/* Register Programming Values!! Change as required */
+#define XLR_I2C_CFG_ADDR 0xF8 /* 8-Bit dev Addr + POR Values */
+#define XLR_I2C_CFG_NOADDR 0xFA /* 8-Bit reg Addr + POR Values */
+#define XLR_I2C_STARTXFR_ND 0x02 /* No data , only addr */
+#define XLR_I2C_STARTXFR_RD 0x01 /* Read */
+#define XLR_I2C_STARTXFR_WR 0x00 /* Write */
+#define XLR_I2C_CLKDIV_DEF 0x14A /* 0x00000052 */
+#define XLR_I2C_HDSTATIM_DEF 0x107 /* 0x00000000 */
+
+#define XLR_I2C_IO_SIZE 0x1000
+
+struct xlr_i2c_private {
+ struct i2c_adapter adap;
+ u32 __iomem *iobase;
+};
+
+static int xlr_i2c_tx(struct xlr_i2c_private *priv, u16 len,
+ u8 *buf, u16 addr)
+{
+ u32 i2c_status = 0x00;
+ u8 nb;
+ int pos, timeout = 0;
+ struct i2c_adapter *adap = &priv->adap;
+ u8 offset = buf[0];
+
+ netlogic_write_reg(priv->iobase, XLR_I2C_ADDR, offset);
+ netlogic_write_reg(priv->iobase, XLR_I2C_DEVADDR, addr);
+ netlogic_write_reg(priv->iobase, XLR_I2C_CFG, XLR_I2C_CFG_ADDR);
+ netlogic_write_reg(priv->iobase, XLR_I2C_BYTECNT, len-1);
+
+retry:
+ timeout = 0;
+ pos = 1;
+ if (len == 1) {
+ netlogic_write_reg(priv->iobase, XLR_I2C_STARTXFR,
+ XLR_I2C_STARTXFR_ND);
+ } else {
+ netlogic_write_reg(priv->iobase, XLR_I2C_DATAOUT, buf[pos]);
+ netlogic_write_reg(priv->iobase, XLR_I2C_STARTXFR,
+ XLR_I2C_STARTXFR_WR);
+ }
+
+ while (1) {
+ if (timeout++ > 0x1000) {
+ dev_err(&adap->dev, "XLR_I2C_STARTXFR_RD Rx Timeout\n");
+ return -ETIMEDOUT;
+ }
+
+ i2c_status = netlogic_read_reg(priv->iobase, XLR_I2C_STATUS);
+
+ if (i2c_status & XLR_I2C_SDOEMPTY) {
+ pos++;
+ nb = (pos < len) ? buf[pos] : 0;
+ netlogic_write_reg(priv->iobase, XLR_I2C_DATAOUT, nb);
+ }
+
+ if (i2c_status & XLR_I2C_ARB_STARTERR)
+ goto retry;
+
+ if (i2c_status & XLR_I2C_ACK_ERR) {
+ dev_err(&priv->adap.dev, "Tx ACK ERR\n");
+ return -EIO;
+ }
+
+ if (i2c_status & XLR_I2C_BUS_BUSY) {
+ udelay(1);
+ continue;
+ }
+
+ if (pos >= len)
+ break;
+ }
+
+ return 0;
+}
+
+static int xlr_i2c_rx(struct xlr_i2c_private *priv, u16 len,
+ u8 *buf, u16 addr)
+{
+ u32 i2c_status = 0x00;
+ int pos = 0;
+ int timeout = 0;
+ struct i2c_adapter *adap = &priv->adap;
+
+ netlogic_write_reg(priv->iobase, XLR_I2C_CFG, XLR_I2C_CFG_NOADDR);
+ netlogic_write_reg(priv->iobase, XLR_I2C_BYTECNT, len);
+ netlogic_write_reg(priv->iobase, XLR_I2C_DEVADDR, addr);
+
+retry:
+ timeout = 0;
+ netlogic_write_reg(priv->iobase, XLR_I2C_STARTXFR,
+ XLR_I2C_STARTXFR_RD);
+
+ while (1) {
+ if (timeout++ > 0x1000) {
+ dev_err(&adap->dev, "XLR_I2C_STARTXFR_RD Rx Timeout\n");
+ return -ETIMEDOUT;
+ }
+
+ i2c_status = netlogic_read_reg(priv->iobase,
+ XLR_I2C_STATUS);
+ if (i2c_status & XLR_I2C_RXRDY) {
+ buf[pos++] = (u8)netlogic_read_reg(priv->iobase,
+ XLR_I2C_DATAIN);
+ }
+
+ if (i2c_status & XLR_I2C_ARB_STARTERR)
+ goto retry;
+
+ if (i2c_status & XLR_I2C_ACK_ERR) {
+ dev_err(&adap->dev, "XLR_I2C_STARTXFR_RD ACK ERR\n");
+ return -EIO;
+ }
+
+ if ((i2c_status & XLR_I2C_BUS_BUSY) == 0)
+ break;
+ udelay(1);
+ }
+ return 0;
+}
+
+static int xlr_i2c_xfer(struct i2c_adapter *adap,
+ struct i2c_msg *msgs, int num)
+{
+ struct i2c_msg *msg;
+ int i;
+ int ret = 0;
+ struct xlr_i2c_private *priv = i2c_get_adapdata(adap);
+
+ for (i = 0; ret == 0 && i < num; i++) {
+ msg = &msgs[i];
+ if (msg->flags & I2C_M_RD)
+ ret = xlr_i2c_rx(priv, msg->len, &msg->buf[0],
+ msg->addr);
+ else
+ ret = xlr_i2c_tx(priv, msg->len, &msg->buf[0],
+ msg->addr);
+ }
+
+ return (ret != 0) ? ret : num;
+}
+
+static u32 xlr_func(struct i2c_adapter *adap)
+{
+ /* Emulate SMBUS over I2C */
+ return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
+}
+
+static struct i2c_algorithm xlr_i2c_algo = {
+ .master_xfer = xlr_i2c_xfer,
+ .functionality = xlr_func,
+};
+
+static int xlr_i2c_add_bus(struct xlr_i2c_private *priv)
+{
+ priv->adap.owner = THIS_MODULE;
+ priv->adap.algo_data = priv;
+ priv->adap.nr = 1;
+ priv->adap.algo = &xlr_i2c_algo;
+ priv->adap.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
+ snprintf(priv->adap.name, sizeof(priv->adap.name),
+ "SMBus XLR I2C Adapter");
+ i2c_set_adapdata(&priv->adap, priv);
+ /* register new adapter to i2c module... */
+ if (i2c_add_numbered_adapter(&priv->adap))
+ return -1;
+
+ return 0;
+}
+
+static int __devinit xlr_i2c_probe(struct platform_device *pdev)
+{
+ struct xlr_i2c_private *priv;
+ struct resource *res;
+ int ret;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+ if (!res) {
+ ret = -ENXIO;
+ goto err1;
+ }
+
+ if (!request_mem_region(res->start, XLR_I2C_IO_SIZE, pdev->name)) {
+ dev_err(&pdev->dev, "request_mem_region failed\n");
+ ret = -ENOMEM;
+ goto err1;
+ }
+
+ priv = kzalloc(sizeof(struct xlr_i2c_private), GFP_KERNEL);
+ if (!priv) {
+ ret = -ENOMEM;
+ goto err2;
+ }
+
+ priv->adap.dev.parent = &pdev->dev;
+ priv->iobase = (u32 *) ioremap(res->start, XLR_I2C_IO_SIZE);
+ if (!priv->iobase) {
+ ret = -ENOMEM;
+ goto err3;
+ }
+
+ platform_set_drvdata(pdev, priv);
+ ret = xlr_i2c_add_bus(priv);
+
+ if (ret < 0) {
+ dev_err(&priv->adap.dev, "Failed to add i2c bus\n");
+ ret = -ENXIO;
+ goto err4;
+ } else
+ dev_info(&priv->adap.dev, "Added I2C Bus.\n");
+
+ return 0;
+err4:
+ iounmap(priv->iobase);
+ platform_set_drvdata(pdev, NULL);
+err3:
+ kfree(priv);
+err2:
+ release_mem_region(res->start, IORESOURCE_MEM);
+err1:
+ return ret;
+}
+
+static int __devexit xlr_i2c_remove(struct platform_device *pdev)
+{
+ struct xlr_i2c_private *priv = platform_get_drvdata(pdev);
+ struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+ i2c_del_adapter(&priv->adap);
+ iounmap(priv->iobase);
+ kfree(priv);
+ release_mem_region(res->start, IORESOURCE_MEM);
+ platform_set_drvdata(pdev, NULL);
+ return 0;
+}
+
+static struct platform_driver xlr_i2c_driver = {
+ .probe = xlr_i2c_probe,
+ .remove = __devexit_p(xlr_i2c_remove),
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "xlr-i2cbus",
+ },
+};
+
+static int __init xlr_i2c_init(void)
+{
+ return platform_driver_register(&xlr_i2c_driver);
+}
+
+static void __exit xlr_i2c_exit(void)
+{
+ platform_driver_unregister(&xlr_i2c_driver);
+}
+
+MODULE_AUTHOR("Ganesan Ramalingam <ganesanr@xxxxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("XLR I2C SMBus driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:xlr-i2cbus");
+
+module_init(xlr_i2c_init);
+module_exit(xlr_i2c_exit);
--
1.7.4.1
--
Jayachandran C.
jayachandranc@xxxxxxxxxxxxxxxxx (Netlogic Microsystems)
jchandra@xxxxxxxxxxx (The FreeBSD Project)
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