From: Jiang Lu <lu.ji...@windriver.com>
I2C driver for the controller on ACP platform.
The EEPROM attached on the bus can be accessed.
Signed-off-by: Jiang Lu <lu.ji...@windriver.com>
---
drivers/i2c/busses/Kconfig | 7 +
drivers/i2c/busses/Makefile | 3 +-
drivers/i2c/busses/acp3400-i2c.c | 510 +++++++++++++++++++++++++++++++++++++++
3 files changed, 519 insertions(+), 1 deletion(-)
create mode 100644 drivers/i2c/busses/acp3400-i2c.c
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 4b3a7ca..a1ff6b0 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -934,4 +934,11 @@ config I2C_AXXIA
If you don't know, say Y.
+config ACP3400_I2C
+ tristate "ACP3400 I2C support"
+ depends on ACP
+ default y
+ help
+ I2C adapter for acp476 based boards
+
endmenu
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 39f9f4f..b325ee6 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -92,4 +92,5 @@ obj-$(CONFIG_SCx200_I2C) += scx200_i2c.o
ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG
-obj-y += ai2c/
+obj-$(CONFIG_I2C_AXXIA) += ai2c/
+obj-$(CONFIG_ACP3400_I2C) += acp3400-i2c.o
diff --git a/drivers/i2c/busses/acp3400-i2c.c b/drivers/i2c/busses/acp3400-i2c.c
new file mode 100644
index 0000000..4a536db
--- /dev/null
+++ b/drivers/i2c/busses/acp3400-i2c.c
@@ -0,0 +1,510 @@
+/*
+ * ACP3400 I2C adapter
+ *
+ * Based on DU-TS I2C Adapter Driver
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <linux/of_platform.h>
+#include <linux/of_i2c.h>
+#include <linux/slab.h>
+
+#include <linux/io.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+
+#define DRV_NAME "acp3400-i2c"
+
+struct acp3400_i2c_regs {
+ unsigned int txconfig;
+ unsigned int rxconfig;
+ unsigned int txstatus;
+ unsigned int rxstatus;
+ unsigned int irqenable;
+ unsigned int irqclear;
+ unsigned int irqstatus;
+ unsigned int clkconfig;
+ unsigned int startsetup;
+ unsigned int stopsetup;
+ unsigned int datasetup;
+ unsigned int bypassmode;
+ unsigned int slaveaddr;
+ unsigned int txdata0;
+ unsigned int txdata1;
+ unsigned int rxdata0;
+ unsigned int rxdata1;
+};
+
+struct acp3400_i2c_timer_regs {
+ unsigned int loadval; /* 0x20 */
+ unsigned int val; /* 0x24 */
+ unsigned int control; /* 0x28 */
+ unsigned int irq_clr; /* 0x2c */
+ unsigned int irq_stat_raw; /* 0x30 */
+ unsigned int irq_stat; /* 0x34 */
+ unsigned int bg_loadval; /* 0x38 */
+};
+
+
+/* Master Clock Configuration */
+/* Configured clock frequency i2c_freq = 100kHz. */
+
+/* I2C register values */
+#define ACPI2C_CLK_100KHZ (1000 | (1000 << 16))
+#define ACPI2C_MSTSHC (940 | (800 << 16))
+#define ACPI2C_MSPSHC (800 | (0 << 16))
+#define ACPI2C_MDSHC (255 | (127 << 16))
+
+#define ACPI2C_XFER_START 0x00000001
+#define ACPI2C_XFER_DONE 0x00000001
+#define ACPI2C_READ_MODE 0x00000200
+#define ACPI2C_STOP_MODE 0x20000000
+#define ACPI2C_MASTER_MODE 0x00000100
+#define ACPI2C_MASTER_OP_CLEAR 0x00000400
+#define ACPI2C_10BIT_ADDR 0x00000080
+#define ACPI2C_CLEAR_IRQ 0x0000000F
+#define ACPI2C_DELAY 500 /* us */
+#define ACPI2C_RETRIES 100
+#define ACPI2C_REG_BSIZE 4 /* bytes */
+#define ACPI2C_DATA_REGS 2
+
+struct acp3400_i2c {
+ struct device *dev;
+ struct i2c_adapter adap;
+ struct acp3400_i2c_regs __iomem *i2c_regs;
+ struct acp3400_i2c_timer_regs __iomem *timer_regs;
+ struct mutex i2c_lock;
+};
+
+#ifdef ACP3400_I2C_DEBUG
+static void dump_regs(struct acp3400_i2c *i2c)
+{
+ pr_info("i2c-reg: txconfig %8.8x\n",
+ in_le32(&i2c->i2c_regs->txconfig));
+ pr_info("i2c-reg: rxconfig %8.8x\n",
+ in_le32(&i2c->i2c_regs->rxconfig));
+ pr_info("i2c-reg: txstatus %8.8x\n",
+ in_le32(&i2c->i2c_regs->txstatus));
+ pr_info("i2c-reg: rxstatus %8.8x\n",
+ in_le32(&i2c->i2c_regs->rxstatus));
+ pr_info("i2c-reg: irqenable %8.8x\n",
+ in_le32(&i2c->i2c_regs->irqenable));
+ pr_info("i2c-reg: irqclear %8.8x\n",
+ in_le32(&i2c->i2c_regs->irqclear));
+ pr_info("i2c-reg: irqstatus %8.8x\n",
+ in_le32(&i2c->i2c_regs->irqstatus));
+ pr_info("i2c-reg: clkconfig %8.8x\n",
+ in_le32(&i2c->i2c_regs->clkconfig));
+ pr_info("i2c-reg: startsetup %8.8x\n",
+ in_le32(&i2c->i2c_regs->startsetup));
+ pr_info("i2c-reg: stopsetup %8.8x\n",
+ in_le32(&i2c->i2c_regs->stopsetup));
+ pr_info("i2c-reg: datasetup %8.8x\n",
+ in_le32(&i2c->i2c_regs->datasetup));
+ pr_info("i2c-reg: bypassmode %8.8x\n",
+ in_le32(&i2c->i2c_regs->bypassmode));
+ pr_info("i2c-reg: slaveaddr %8.8x\n",
+ in_le32(&i2c->i2c_regs->slaveaddr));
+ pr_info("i2c-reg: txdata0 %8.8x\n",
+ in_le32(&i2c->i2c_regs->txdata0));
+ pr_info("i2c-reg: txdata1 %8.8x\n",
+ in_le32(&i2c->i2c_regs->txdata1));
+ pr_info("i2c-reg: rxdata0 %8.8x\n",
+ in_le32(&i2c->i2c_regs->rxdata0));
+ pr_info("i2c-reg: rxdata1 %8.8x\n",
+ in_le32(&i2c->i2c_regs->rxdata1));
+ pr_info("i2c-timer-reg: loadval %8.8x\n",
+ in_le32(&i2c->timer_regs->loadval));
+ pr_info("i2c-timer-reg: val %8.8x\n",
+ in_le32(&i2c->timer_regs->val));
+ pr_info("i2c-timer-reg: control %8.8x\n",
+ in_le32(&i2c->timer_regs->control));
+}
+#endif
+/*
+ * Low level write routine
+ */
+static int acp3400_i2c_write_bytes(struct acp3400_i2c *i2c,
+ struct i2c_msg *msgs)
+{
+ unsigned char *bufp = msgs->buf;
+ unsigned int reg_value, data[2] = {0, 0};
+ int cnt, ret = 0;
+
+ if (msgs->len > (ACPI2C_REG_BSIZE * ACPI2C_DATA_REGS))
+ msgs->len = ACPI2C_REG_BSIZE * ACPI2C_DATA_REGS;
+
+ /* Set message */
+ for (cnt = 0; cnt < msgs->len; cnt++) {
+ data[1] <<= 8;
+ data[1] |= ((data[0] >> 24) & 0xFF);
+ data[0] <<= 8;
+ data[0] |= bufp[cnt];
+ }
+ out_le32(&i2c->i2c_regs->txdata0, data[0]);
+ out_le32(&i2c->i2c_regs->txdata1, data[1]);
+
+ /* setup and start a transmission */
+ reg_value = ACPI2C_MASTER_MODE | ACPI2C_STOP_MODE;
+ reg_value |= (msgs->len << 1) & 0x1e;
+ if (msgs->flags & I2C_M_TEN) {
+ reg_value |= ACPI2C_10BIT_ADDR;
+ /* TODO update slave address accordingly */
+ }
+ out_le32(&i2c->i2c_regs->txconfig, reg_value);
+
+ reg_value &= ~ACPI2C_STOP_MODE;
+ out_le32(&i2c->i2c_regs->txconfig, reg_value);
+
+ reg_value |= ACPI2C_XFER_START;
+ out_le32(&i2c->i2c_regs->txconfig, reg_value);
+
+ /* Check if the message has been sent
+ * Wait a totally of 1 s for the transmission */
+ reg_value = cnt = 0;
+ while (0 == reg_value && cnt++ < ACPI2C_RETRIES) {
+ udelay(ACPI2C_DELAY);
+ /* Read transmission status */
+ reg_value = in_le32(&i2c->i2c_regs->txstatus);
+ }
+#ifdef ACP3400_I2C_DEBUG
+ if (ACPI2C_XFER_DONE != reg_value)
+ dump_regs(i2c);
+#endif
+ /* Clear registers */
+ out_le32(&i2c->i2c_regs->irqclear, ACPI2C_CLEAR_IRQ);
+ out_le32(&i2c->i2c_regs->txconfig, ACPI2C_MASTER_OP_CLEAR);
+
+ out_le32(&i2c->i2c_regs->txconfig, ACPI2C_STOP_MODE);
+
+ if (ACPI2C_XFER_DONE == reg_value)
+ ret = msgs->len;
+ else
+ ret = -EIO;
+
+ return ret;
+}
+
+/*
+ * Low level read routine
+ */
+
+static int acp3400_i2c_read_bytes(struct acp3400_i2c *i2c,
+ struct i2c_msg *msgs)
+{
+ unsigned char *bufp = msgs->buf;
+ unsigned int reg_value, data[2];
+ int cnt, ret = 0;
+
+ if (msgs->len > (ACPI2C_REG_BSIZE * ACPI2C_DATA_REGS))
+ msgs->len = ACPI2C_REG_BSIZE * ACPI2C_DATA_REGS;
+
+ /* Setup a reception */
+ reg_value = (msgs->len << 1) & 0x1e;
+ if (msgs->flags & I2C_M_TEN) {
+ reg_value |= ACPI2C_10BIT_ADDR;
+ /* TODO update slave address accordingly */
+ }
+ out_le32(&i2c->i2c_regs->rxconfig, reg_value);
+
+ /* set read mode and start clock */
+ reg_value |= ACPI2C_XFER_START;
+ out_le32(&i2c->i2c_regs->rxconfig, reg_value);
+
+ reg_value = ACPI2C_STOP_MODE | ACPI2C_MASTER_MODE | ACPI2C_READ_MODE;
+ out_le32(&i2c->i2c_regs->txconfig, reg_value);
+
+ reg_value &= ~ACPI2C_STOP_MODE;
+ out_le32(&i2c->i2c_regs->txconfig, reg_value);
+
+ reg_value |= ACPI2C_XFER_START;
+ out_le32(&i2c->i2c_regs->txconfig, reg_value);
+
+ /* Check if the message has been received
+ * Wait a totally of 1 s for the reception */
+ reg_value = cnt = 0;
+ while (0 == (ACPI2C_XFER_DONE & reg_value) &&
+ cnt++ < ACPI2C_RETRIES) {
+ udelay(ACPI2C_DELAY);
+ /* Read transmission status */
+ reg_value = in_le32(&i2c->i2c_regs->rxstatus);
+ }
+
+ /* get message */
+ data[0] = in_le32(&i2c->i2c_regs->rxdata0);
+ data[1] = in_le32(&i2c->i2c_regs->rxdata1);
+ for (cnt = 0; cnt < msgs->len; cnt++) {
+ if (cnt < ACPI2C_REG_BSIZE)
+ bufp[cnt] = data[0] >> ((8 * cnt) & 0xFF);
+ else
+ bufp[cnt] = data[1] >>
+ ((8 * (cnt - ACPI2C_REG_BSIZE)) & 0xFF);
+ }
+#ifdef ACP3400_I2C_DEBUG
+ if (ACPI2C_XFER_DONE != (reg_value & 0x03))
+ dump_regs(i2c);
+#endif
+ /* clear registers */
+ out_le32(&i2c->i2c_regs->irqclear, ACPI2C_CLEAR_IRQ);
+ out_le32(&i2c->i2c_regs->txconfig, ACPI2C_MASTER_OP_CLEAR);
+
+ out_le32(&i2c->i2c_regs->txconfig, ACPI2C_STOP_MODE);
+
+ if (ACPI2C_XFER_DONE == (reg_value & 0x03))
+ ret = msgs->len;
+ else
+ ret = -EIO;
+
+ return ret;
+}
+
+/*
+ * I2C timer setup
+ */
+static void acp3400_i2c_timer_setup(struct acp3400_i2c *i2c)
+{
+ /* disable timer 1 */
+ out_le32(&i2c->timer_regs->control, 0);
+ /* Program the Timer1 Load Value register with a value that sets
+ * the timer period to 250 ns (that is, 4 MHz frequency). When you
+ * configure the ACP peripheral clock (clk_per) for 200 MHz, the
+ * Timer1 Load Value is 0x31. */
+ out_le32(&i2c->timer_regs->loadval, 0x31);
+ out_le32(&i2c->timer_regs->bg_loadval, 0x31);
+
+ /* Configure and enable Timer1 for periodic wrapping mode
+ * with a prescaler of 1 by writing 0xc0 to the Timer1 Control
+ * Register. */
+ out_le32(&i2c->timer_regs->control, 0xc0);
+}
+/*
+ * Low level master transfer routine
+ */
+static int acp3400_i2c_xfer_bytes(struct acp3400_i2c *i2c,
+ struct i2c_msg *msgs)
+{
+ int ret = 0;
+
+ mutex_lock(&i2c->i2c_lock);
+ /* Prepare ACP3400 I2C for a transaction */
+ out_le32(&i2c->i2c_regs->txconfig,
+ ACPI2C_MASTER_OP_CLEAR | ACPI2C_MASTER_MODE);
+
+ out_le32(&i2c->i2c_regs->txconfig,
+ ACPI2C_MASTER_MODE | ACPI2C_STOP_MODE);
+
+ /* I2C clock frequency and duty cycle */
+ out_le32(&i2c->i2c_regs->clkconfig, ACPI2C_CLK_100KHZ);
+ /* The setup and hold durations for the START condition. */
+ out_le32(&i2c->i2c_regs->startsetup, ACPI2C_MSTSHC);
+ /* The setup and hold durations for the STOP condition. */
+ out_le32(&i2c->i2c_regs->stopsetup, ACPI2C_MSPSHC);
+ /* The setup and hold durations for the data bits. */
+ out_le32(&i2c->i2c_regs->datasetup, ACPI2C_MDSHC);
+ /* Set Slave Address */
+ out_le32(&i2c->i2c_regs->slaveaddr, msgs->addr);
+ /* Disable the actions for which the host requires to be interrupted */
+ out_le32(&i2c->i2c_regs->irqenable, 0);
+
+ /* Send/Receive Data */
+ if (msgs->flags & I2C_M_RD)
+ ret = acp3400_i2c_read_bytes(i2c, msgs);
+ else
+ ret = acp3400_i2c_write_bytes(i2c, msgs);
+
+ mutex_unlock(&i2c->i2c_lock);
+ return ret;
+}
+static void acp3400_i2c_dummy_xfer(struct acp3400_i2c *i2c)
+{
+ /* Prepare ACP3400 I2C for a transaction */
+ out_le32(&i2c->i2c_regs->txconfig,
+ ACPI2C_MASTER_OP_CLEAR | ACPI2C_MASTER_MODE);
+
+ out_le32(&i2c->i2c_regs->txconfig,
+ ACPI2C_MASTER_MODE | ACPI2C_STOP_MODE);
+
+ /* I2C clock frequency and duty cycle */
+ out_le32(&i2c->i2c_regs->clkconfig, ACPI2C_CLK_100KHZ);
+ /* The setup and hold durations for the START condition. */
+ out_le32(&i2c->i2c_regs->startsetup, ACPI2C_MSTSHC);
+ /* The setup and hold durations for the STOP condition. */
+ out_le32(&i2c->i2c_regs->stopsetup, ACPI2C_MSPSHC);
+ /* The setup and hold durations for the data bits. */
+ out_le32(&i2c->i2c_regs->datasetup, ACPI2C_MDSHC);
+ /* Set Dummy Slave Address */
+ out_le32(&i2c->i2c_regs->slaveaddr, 0x7f);
+ /* Disable the actions for which the host requires to be interrupted */
+ out_le32(&i2c->i2c_regs->irqenable, 0);
+ /* Number of bytes 0, clear stop mode */
+ out_le32(&i2c->i2c_regs->txconfig, ACPI2C_MASTER_MODE);
+
+ /* Set Transmit Ready - triggers the transmit transaction */
+ out_le32(&i2c->i2c_regs->txconfig,
+ (ACPI2C_XFER_START | ACPI2C_MASTER_MODE));
+
+}
+
+/*
+ * Generic master transfer entrypoint.
+ * Returns the number of processed messages or error (<0)
+ */
+static int acp3400_i2c_xfer(struct i2c_adapter *adap,
+ struct i2c_msg *msgs, int num)
+{
+ struct acp3400_i2c *i2c = i2c_get_adapdata(adap);
+ int msg_cnt, ret = 0;
+
+ if (!num)
+ return 0;
+
+#ifdef ACP3400_I2C_DEBUG
+ if (num == 1 && msgs[0].addr == 0x7f && msgs[0].len == 0) {
+ mutex_lock(&i2c->i2c_lock);
+ acp3400_i2c_dummy_xfer(i2c);
+ mutex_unlock(&i2c->i2c_lock);
+ return 0;
+ }
+#endif
+ /*
+ * Check the sanity of the passed messages.
+ * Uhh, generic i2c layer is more suitable place for such code...
+ */
+ if ((msgs[0].addr > 0x3ff) ||
+ (!(msgs[0].flags & I2C_M_TEN) && (msgs[0].addr > 0x7f)))
+ return -EINVAL;
+
+ for (msg_cnt = 0; msg_cnt < num; ++msg_cnt) {
+ if (msgs[msg_cnt].len <= 0)
+ return -EINVAL;
+ if ((msgs[0].addr != msgs[msg_cnt].addr) ||
+ ((msgs[0].flags & I2C_M_TEN) !=
+ (msgs[msg_cnt].flags & I2C_M_TEN)))
+ return -EINVAL;
+ }
+
+ /* Do real transfer */
+ for (msg_cnt = 0; msg_cnt < num; msg_cnt++)
+ ret = acp3400_i2c_xfer_bytes(i2c, &msgs[msg_cnt]);
+ return ret < 0 ? ret : num;
+}
+
+static u32 acp3400_i2c_functionality(struct i2c_adapter *adapter)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR;
+}
+
+static const struct i2c_algorithm acp3400_i2c_algo = {
+ .master_xfer = acp3400_i2c_xfer,
+ .functionality = acp3400_i2c_functionality,
+};
+
+static struct i2c_adapter acp3400_i2c_ops = {
+ .owner = THIS_MODULE,
+ .name = "ACP3400 adapter",
+ .class = I2C_CLASS_HWMON | I2C_CLASS_SPD,
+ .algo = &acp3400_i2c_algo,
+ .timeout = HZ,
+};
+
+static int acp34xx_i2c_probe(struct platform_device *dev)
+{
+ struct device_node *np = dev->dev.of_node;
+
+ struct acp3400_i2c *i2c;
+ int result = -ENODEV;
+
+ i2c = kzalloc(sizeof(*i2c), GFP_KERNEL);
+ if (!i2c)
+ goto err;
+
+ i2c->i2c_regs = of_iomap(np, 0);
+ i2c->timer_regs = of_iomap(np, 1);
+ if (!i2c->i2c_regs || !i2c->timer_regs) {
+ pr_err("%s: failed to map I/O\n", np->full_name);
+ goto err;
+ }
+
+ i2c->adap = acp3400_i2c_ops;
+ i2c_set_adapdata(&i2c->adap, i2c);
+ i2c->adap.dev.of_node = of_node_get(np);
+ mutex_init(&i2c->i2c_lock);
+
+ /* I2C timer setup */
+ acp3400_i2c_timer_setup(i2c);
+ acp3400_i2c_dummy_xfer(i2c);
+ result = i2c_add_adapter(&i2c->adap);
+ if (result < 0) {
+ pr_err("%s: failed to add adapter\n",
+ np->full_name);
+ goto err;
+ }
+
+ pr_info("%s: adapter has been added\n", np->full_name);
+
+ of_i2c_register_devices(&i2c->adap);
+
+ dev_set_drvdata(&dev->dev, i2c);
+ return 0;
+err:
+ if (i2c) {
+ if (i2c->i2c_regs)
+ iounmap(i2c->i2c_regs);
+ if (i2c->timer_regs)
+ iounmap(i2c->timer_regs);
+ kfree(i2c);
+ }
+
+ return result;
+}
+
+
+static int acp34xx_i2c_remove(struct platform_device *dev)
+{
+ struct acp3400_i2c *i2c = dev_get_drvdata(&dev->dev);
+
+ i2c_del_adapter(&i2c->adap);
+ kfree(i2c);
+
+ return 0;
+}
+
+static struct of_device_id acp_i2c_match[] = {
+ {
+ .compatible = "acp-i2c",
+ },
+ {
+ .compatible = "acp,acp3400-i2c",
+ },
+ { /* end of list */ },
+};
+
+static struct platform_driver acp_i2c_driver = {
+ .driver = {
+ .name = "acp-i2c",
+ .owner = THIS_MODULE,
+ .of_match_table = acp_i2c_match,
+ },
+ .probe = acp34xx_i2c_probe,
+ .remove = acp34xx_i2c_remove,
+};
+
+module_platform_driver(acp_i2c_driver);
+
+MODULE_AUTHOR("Andrey Panteleev <andrey.xx.pantel...@ericsson.com>");
+MODULE_DESCRIPTION("I2C adapter for ACP3400");
+MODULE_LICENSE("GPL");
--
1.8.3
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