This is a patch to add i2c algorith support for nxp sc18im700
master i2c bus controller with uart interface
Signed-off-by: Raghavendra Chandra Ganiga <ravi23gan...@gmail.com>
---
drivers/i2c/algos/Kconfig | 2 +
drivers/i2c/algos/Makefile | 1 +
drivers/i2c/algos/i2c-algo-sc18im700.c | 274 +++++++++++++++++++++++++++++++++
include/linux/i2c-algo-sc18im700.h | 81 ++++++++++
4 files changed, 358 insertions(+)
create mode 100644 drivers/i2c/algos/i2c-algo-sc18im700.c
create mode 100644 include/linux/i2c-algo-sc18im700.h
diff --git a/drivers/i2c/algos/Kconfig b/drivers/i2c/algos/Kconfig
index f1cfe7e..03776c8 100644
--- a/drivers/i2c/algos/Kconfig
+++ b/drivers/i2c/algos/Kconfig
@@ -14,4 +14,6 @@ config I2C_ALGOPCF
config I2C_ALGOPCA
tristate "I2C PCA 9564 interfaces"
+config I2C_ALGOSC18IM700
+ tristate "I2C SC18IM700 interfaces"
endmenu
diff --git a/drivers/i2c/algos/Makefile b/drivers/i2c/algos/Makefile
index 215303f..26f92d7 100644
--- a/drivers/i2c/algos/Makefile
+++ b/drivers/i2c/algos/Makefile
@@ -5,5 +5,6 @@
obj-$(CONFIG_I2C_ALGOBIT) += i2c-algo-bit.o
obj-$(CONFIG_I2C_ALGOPCF) += i2c-algo-pcf.o
obj-$(CONFIG_I2C_ALGOPCA) += i2c-algo-pca.o
+obj-$(CONFIG_I2C_ALGOSC18IM700) += i2c-algo-sc18im700.o
ccflags-$(CONFIG_I2C_DEBUG_ALGO) := -DDEBUG
diff --git a/drivers/i2c/algos/i2c-algo-sc18im700.c
b/drivers/i2c/algos/i2c-algo-sc18im700.c
new file mode 100644
index 0000000..cf73aad
--- /dev/null
+++ b/drivers/i2c/algos/i2c-algo-sc18im700.c
@@ -0,0 +1,274 @@
+/*
+ * i2c-algo-sc18im700.c i2c driver algorithms for SC18IM700 adapters
+ * Master I2C bus with UART interface
+ *
+ * Copyright (C) 2014 Raghavendra Chandra Ganiga <ravi23gan...@gmail.com>
+ *
+ * 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 <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/i2c.h>
+#include <linux/i2c-algo-sc18im700.h>
+
+#define DEB1(x) if (i2c_debug >= 1) x
+
+static int i2c_debug;
+
+#define set_sc18im(adap, value) adap->set_data(adap->data, value)
+#define get_sc18im(adap, buff) adap->get_data(adap->data, buff)
+#define sc18im_reset(adap) adap->reset(adap->data)
+#define sc18im_get_own_addr(adap) adap->get_own_addr(adap->data)
+
+static unsigned char sc18im_read_reg(struct i2c_algo_sc18imdata *adap,
+ unsigned char reg, unsigned char *buf)
+{
+ set_sc18im(adap, SC18IM_REG_READ);
+ set_sc18im(adap, reg);
+ set_sc18im(adap, SC18IM_STOP);
+ return get_sc18im(adap, buf);
+}
+
+static void sc18im_write_reg(struct i2c_algo_sc18imdata *adap,
+ unsigned char reg, unsigned char value)
+{
+ set_sc18im(adap, SC18IM_REG_WRITE);
+ set_sc18im(adap, reg);
+ set_sc18im(adap, value);
+ set_sc18im(adap, SC18IM_STOP);
+}
+
+static int sc18im_xfer(struct i2c_adapter *adap,
+ struct i2c_msg *msgs,
+ int num)
+{
+ struct i2c_algo_sc18imdata *algo_data = adap->algo_data;
+ struct i2c_msg *msg;
+ int curmsg, addr, numbytes;
+ unsigned char data;
+
+ DEB1(printk(KERN_DEBUG "i2c algo sc18im700: Transfer Starts"));
+
+ if (algo_data->xfer_begin)
+ algo_data->xfer_begin(algo_data->data);
+
+ curmsg = 0;
+ while (curmsg < num) {
+ numbytes = 0;
+ msg = &msgs[curmsg];
+
+ DEB1(printk(KERN_DEBUG "i2c algo sc18im700: Operation: %s, "
+ "Addr: 0x%02x, Length: %d, "
+ "Current Transfer No: %d, "
+ "Total No of transfer: %d\n",
+ (msg->flags & I2C_M_RD) ? "Read" : "Write",
+ msg->addr, msg->len, (curmsg + 1), num));
+
+ /* Data frame in sc18im700 for write is
+ * start_char;address;length;data1;data2;---;data.n
+ *;terminate_char
+ * first provide the start character followed by address,
+ * length, data bytes upto length bytes and then terminate
+ * character, as terminate character is received by sc18im700
+ * it transfers the data to addressed device
+ * Data frame for read is
+ * start_char;address;length;terminate_char;data1;data2.---
+ *;data.n
+ * similarly in read operation , as terminate character
+ * is received, the data is read from the addressed device
+ * and given out in uart
+ */
+ set_sc18im(algo_data, SC18IM_START);
+
+ addr = (msg->addr & 0x7F) << 1;
+ if (msg->flags & I2C_M_RD)
+ addr |= 1;
+ if (msg->flags & I2C_M_REV_DIR_ADDR)
+ addr ^= 1;
+ set_sc18im(algo_data, addr);
+
+ set_sc18im(algo_data, msg->len);
+
+ if (msg->flags & I2C_M_RD) {
+ set_sc18im(algo_data, SC18IM_STOP);
+
+ while (numbytes < msg->len) {
+ data = get_sc18im(algo_data,
+ &msg->buf[numbytes]);
+ if (data) {
+ DEB1(printk(KERN_ERR
+ "i2c algo sc18im700: Read Error"));
+ curmsg = -ENXIO;
+ goto out;
+ }
+ }
+ } else {
+ while (numbytes < msg->len) {
+ set_sc18im(algo_data, msg->buf[numbytes]);
+ numbytes++;
+ }
+
+ set_sc18im(algo_data, SC18IM_STOP);
+ sc18im_read_reg(algo_data, SC18IM_I2CSTATUS, &data);
+ if (data != I2C_SC18IM_OK) {
+ DEB1(printk(KERN_ERR
+ "i2c algo sc18im700: Write Error"));
+ curmsg = -ENXIO;
+ goto out;
+ }
+ }
+
+ curmsg++;
+ }
+
+out:
+ DEB1(printk(KERN_DEBUG "i2c algo sc18im700: Transfer Ends"));
+
+ if (algo_data->xfer_end)
+ algo_data->xfer_end(algo_data->data);
+
+ return curmsg;
+}
+
+static u32 sc18im_functionality(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
+ I2C_FUNC_PROTOCOL_MANGLING;
+}
+
+static int sc18im_init(struct i2c_adapter *adap)
+{
+ struct i2c_algo_sc18imdata *algo_data = adap->algo_data;
+ unsigned char data;
+
+ sc18im_reset(algo_data);
+
+ /* after reset sc18im700 gives out
+ * OK response in ascii format
+ */
+ get_sc18im(algo_data, &data);
+ if (data != 'O') {
+ DEB1(printk(KERN_ERR
+ "i2c algo sc18im700: Reset response OK not received\n"));
+
+ return -ENXIO;
+ }
+
+ get_sc18im(algo_data, &data);
+ if (data != 'K') {
+ DEB1(printk(KERN_ERR
+ "i2c algo sc18im700: Reset response OK not received\n"));
+
+ return -ENXIO;
+ }
+
+ switch (algo_data->clock_freq) {
+ case I2C_SC18IM_369KHZ:
+ printk(KERN_INFO
+ "i2c algo sc18im700: Clock frequency is 369 KHz\n");
+ break;
+ case I2C_SC18IM_246KHZ:
+ printk(KERN_INFO
+ "i2c algo sc18im700: Clock frequency is 246 KHz\n");
+ break;
+ case I2C_SC18IM_147KHZ:
+ printk(KERN_INFO
+ "i2c algo sc18im700: Clock frequency is 147 KHz\n");
+ break;
+ case I2C_SC18IM_123KHZ:
+ printk(KERN_INFO
+ "i2c algo sc18im700: Clock frequency is 123 KHz\n");
+ break;
+ case I2C_SC18IM_74KHZ:
+ printk(KERN_INFO
+ "i2c algo sc18im700: Clock frequency is 74 KHz\n");
+ break;
+ case I2C_SC18IM_61KHZ:
+ printk(KERN_INFO
+ "i2c algo sc18im700: Clock frequency is 61 KHz\n");
+ break;
+ case I2C_SC18IM_37KHZ:
+ printk(KERN_INFO
+ "i2c algo sc18im700: Clock frequency is 37 KHz\n");
+ break;
+ default:
+ printk(KERN_WARNING
+ "i2c algo sc18im700: Invalid Freq: Clock: 37 KHz\n");
+ algo_data->clock_freq = I2C_SC18IM_37KHZ;
+ }
+
+ /* passed clock frequency is divided into
+ * half and stored in clock high and clock
+ * low to achieve the desired clock frequency
+ */
+ data = algo_data->clock_freq / 2;
+
+ sc18im_write_reg(algo_data, SC18IM_I2C_CLK_LOW, data);
+ sc18im_write_reg(algo_data, SC18IM_I2C_CLK_HIGH, data);
+
+ data = sc18im_get_own_addr(algo_data);
+ sc18im_write_reg(algo_data, SC18IM_I2CADDR, data);
+
+ printk(KERN_DEBUG "i2c algo sc18im700: detected and initialized\n");
+
+ return 0;
+}
+
+static const struct i2c_algorithm sc18im_algo = {
+ .master_xfer = sc18im_xfer,
+ .functionality = sc18im_functionality,
+};
+
+/*
+ * registering functions to load algorithms at runtime
+ */
+int i2c_sc18im_add_bus(struct i2c_adapter *adap)
+{
+ int ret;
+
+ adap->algo = &sc18im_algo;
+
+ ret = sc18im_init(adap);
+ if (ret)
+ return ret;
+
+ return i2c_add_adapter(adap);
+}
+EXPORT_SYMBOL(i2c_sc18im_add_bus);
+
+int i2c_sc18im_add_numbered_bus(struct i2c_adapter *adap)
+{
+ int ret;
+
+ adap->algo = &sc18im_algo;
+
+ ret = sc18im_init(adap);
+ if (ret)
+ return ret;
+
+ return i2c_add_numbered_adapter(adap);
+}
+EXPORT_SYMBOL(i2c_sc18im_add_numbered_bus);
+
+module_param(i2c_debug, int, S_IRUGO | S_IWUSR);
+
+MODULE_PARM_DESC(i2c_debug, "debug level - 0 - off, 1 - more verbose");
+MODULE_DESCRIPTION("SC18IM700 I2C Algorithm Driver");
+MODULE_AUTHOR("Raghavendra Chandra Ganiga <ravi23gan...@gmail.com>");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/i2c-algo-sc18im700.h
b/include/linux/i2c-algo-sc18im700.h
new file mode 100644
index 0000000..231dbd2
--- /dev/null
+++ b/include/linux/i2c-algo-sc18im700.h
@@ -0,0 +1,81 @@
+/*
+ * i2c-algo-sc18im700.c i2c driver algorithms header file
+ *
+ * Copyright (C) 2014 Raghavendra Chandra Ganiga <ravi23gan...@gmail.com>
+ *
+ * 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.
+ */
+
+#ifndef _LINUX_I2C_ALGO_SC18IM700_H
+#define _LINUX_I2C_ALGO_SC18IM700_H
+
+/* SC18IM700 Internal Registers */
+
+#define SC18IM_BRG0 0x00
+#define SC18IM_BRG1 0x01
+#define SC18IM_PORT_CONF1 0x02
+#define SC18IM_PORT_CONF2 0x03
+#define SC18IM_IOSTATE 0x04
+#define SC18IM_I2CADDR 0x06
+#define SC18IM_I2C_CLK_LOW 0x07
+#define SC18IM_I2C_CLK_HIGH 0x08
+#define SC18IM_I2CTO 0x09
+#define SC18IM_I2CSTATUS 0x0A
+
+/* SC18IM700 I2C Commands */
+
+#define SC18IM_START 0x53
+#define SC18IM_STOP 0x50
+#define SC18IM_REG_READ 0x52
+#define SC18IM_REG_WRITE 0x57
+#define SC18IM_READ_GPIO 0x49
+#define SC18IM_WRITE_GPIO 0x4F
+#define SC18IM_POWER_DOWN 0x5A
+
+/* SC18IM700 I2C Clock frequencies */
+
+#define I2C_SC18IM_369KHZ 0x0A
+#define I2C_SC18IM_246KHZ 0x0F
+#define I2C_SC18IM_147KHZ 0x19
+#define I2C_SC18IM_123KHZ 0x1E
+#define I2C_SC18IM_74KHZ 0x32
+#define I2C_SC18IM_61KHZ 0x3C
+#define I2C_SC18IM_37KHZ 0x64
+
+/* SC18IM700 I2C TRANSACTION STATUS */
+
+#define I2C_SC18IM_OK 0xF0
+#define I2C_SC18IM_NACK_ADDR 0xF1
+#define I2C_SC18IM_NACK_DATA 0xF2
+#define I2C_SC18IM_TMOUT 0xF8
+
+struct i2c_algo_sc18imdata {
+ /* private low level data */
+ void *data;
+ unsigned char clock_freq;
+
+ void (*set_data) (void *data, unsigned char value);
+ int (*get_data) (void *data, unsigned char *buff);
+ void (*reset) (void *data);
+ unsigned char (*get_own_addr) (void *data);
+ void (*xfer_begin) (void *data);
+ void (*xfer_end) (void *data);
+};
+
+int i2c_sc18im_add_bus(struct i2c_adapter *);
+int i2c_sc18im_add_numbered_bus(struct i2c_adapter *);
+
+#endif /* _LINUX_I2C_ALGO_SC18IM700_H */
--
1.9.1
--
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