--- /dev/null
+#ifndef __ASM_ARCH_NUC900_I2C_H
+#define __ASM_ARCH_NUC900_I2C_H
+
+struct nuc900_platform_i2c {
+ int bus_num;
+ unsigned long bus_freq;
+};
+
+#endif /* __ASM_ARCH_NUC900_I2C_H */
If you say yes to this option, support will be included for the
I2C interface from ST-Ericsson's Nomadik and Ux500 architectures.
+config I2C_NUC900
+ tristate "NUC900 I2C Driver"
+ depends on ARCH_W90X900
+ help
+ Say Y here to include support for I2C controller in the
+ Winbond/Nuvoton NUC900 based System-on-Chip devices.
+
config I2C_OCORES
tristate "OpenCores I2C Controller"
depends on EXPERIMENTAL
will be called i2c-pmcmsp.
config I2C_PNX
- tristate "I2C bus support for Philips PNX targets"
- depends on ARCH_PNX4008
+ tristate "I2C bus support for Philips PNX and NXP LPC targets"
+ depends on ARCH_PNX4008 || ARCH_LPC32XX
help
This driver supports the Philips IP3204 I2C IP block master and/or
slave controller
obj-$(CONFIG_I2C_MPC) += i2c-mpc.o
obj-$(CONFIG_I2C_MV64XXX) += i2c-mv64xxx.o
obj-$(CONFIG_I2C_NOMADIK) += i2c-nomadik.o
+obj-$(CONFIG_I2C_NUC900) += i2c-nuc900.o
obj-$(CONFIG_I2C_OCORES) += i2c-ocores.o
obj-$(CONFIG_I2C_OMAP) += i2c-omap.o
obj-$(CONFIG_I2C_PASEMI) += i2c-pasemi.o
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/slab.h>
+#include <linux/cpufreq.h>
+#include <linux/gpio.h>
#include <mach/hardware.h>
-
#include <mach/i2c.h>
/* ----- global defines ----------------------------------------------- */
#define DAVINCI_I2C_TIMEOUT (1*HZ)
+#define DAVINCI_I2C_MAX_TRIES 2
#define I2C_DAVINCI_INTR_ALL (DAVINCI_I2C_IMR_AAS | \
DAVINCI_I2C_IMR_SCD | \
DAVINCI_I2C_IMR_ARDY | \
#define DAVINCI_I2C_IVR_NACK 0x02
#define DAVINCI_I2C_IVR_AL 0x01
-#define DAVINCI_I2C_STR_BB (1 << 12)
-#define DAVINCI_I2C_STR_RSFULL (1 << 11)
-#define DAVINCI_I2C_STR_SCD (1 << 5)
-#define DAVINCI_I2C_STR_ARDY (1 << 2)
-#define DAVINCI_I2C_STR_NACK (1 << 1)
-#define DAVINCI_I2C_STR_AL (1 << 0)
-
-#define DAVINCI_I2C_MDR_NACK (1 << 15)
-#define DAVINCI_I2C_MDR_STT (1 << 13)
-#define DAVINCI_I2C_MDR_STP (1 << 11)
-#define DAVINCI_I2C_MDR_MST (1 << 10)
-#define DAVINCI_I2C_MDR_TRX (1 << 9)
-#define DAVINCI_I2C_MDR_XA (1 << 8)
-#define DAVINCI_I2C_MDR_RM (1 << 7)
-#define DAVINCI_I2C_MDR_IRS (1 << 5)
-
-#define DAVINCI_I2C_IMR_AAS (1 << 6)
-#define DAVINCI_I2C_IMR_SCD (1 << 5)
-#define DAVINCI_I2C_IMR_XRDY (1 << 4)
-#define DAVINCI_I2C_IMR_RRDY (1 << 3)
-#define DAVINCI_I2C_IMR_ARDY (1 << 2)
-#define DAVINCI_I2C_IMR_NACK (1 << 1)
-#define DAVINCI_I2C_IMR_AL (1 << 0)
-
-#define MOD_REG_BIT(val, mask, set) do { \
- if (set) { \
- val |= mask; \
- } else { \
- val &= ~mask; \
- } \
-} while (0)
+#define DAVINCI_I2C_STR_BB BIT(12)
+#define DAVINCI_I2C_STR_RSFULL BIT(11)
+#define DAVINCI_I2C_STR_SCD BIT(5)
+#define DAVINCI_I2C_STR_ARDY BIT(2)
+#define DAVINCI_I2C_STR_NACK BIT(1)
+#define DAVINCI_I2C_STR_AL BIT(0)
+
+#define DAVINCI_I2C_MDR_NACK BIT(15)
+#define DAVINCI_I2C_MDR_STT BIT(13)
+#define DAVINCI_I2C_MDR_STP BIT(11)
+#define DAVINCI_I2C_MDR_MST BIT(10)
+#define DAVINCI_I2C_MDR_TRX BIT(9)
+#define DAVINCI_I2C_MDR_XA BIT(8)
+#define DAVINCI_I2C_MDR_RM BIT(7)
+#define DAVINCI_I2C_MDR_IRS BIT(5)
+
+#define DAVINCI_I2C_IMR_AAS BIT(6)
+#define DAVINCI_I2C_IMR_SCD BIT(5)
+#define DAVINCI_I2C_IMR_XRDY BIT(4)
+#define DAVINCI_I2C_IMR_RRDY BIT(3)
+#define DAVINCI_I2C_IMR_ARDY BIT(2)
+#define DAVINCI_I2C_IMR_NACK BIT(1)
+#define DAVINCI_I2C_IMR_AL BIT(0)
struct davinci_i2c_dev {
struct device *dev;
u8 *buf;
size_t buf_len;
int irq;
+ int stop;
u8 terminate;
struct i2c_adapter adapter;
+#ifdef CONFIG_CPU_FREQ
+ struct completion xfr_complete;
+ struct notifier_block freq_transition;
+#endif
};
/* default platform data to use if not supplied in the platform_device */
return __raw_readw(i2c_dev->base + reg);
}
-/*
- * This functions configures I2C and brings I2C out of reset.
- * This function is called during I2C init function. This function
- * also gets called if I2C encounters any errors.
+/* Generate a pulse on the i2c clock pin. */
+static void generic_i2c_clock_pulse(unsigned int scl_pin)
+{
+ u16 i;
+
+ if (scl_pin) {
+ /* Send high and low on the SCL line */
+ for (i = 0; i < 9; i++) {
+ gpio_set_value(scl_pin, 0);
+ udelay(20);
+ gpio_set_value(scl_pin, 1);
+ udelay(20);
+ }
+ }
+}
+
+/* This routine does i2c bus recovery as specified in the
+ * i2c protocol Rev. 03 section 3.16 titled "Bus clear"
*/
-static int i2c_davinci_init(struct davinci_i2c_dev *dev)
+static void i2c_recover_bus(struct davinci_i2c_dev *dev)
+{
+ u32 flag = 0;
+ struct davinci_i2c_platform_data *pdata = dev->dev->platform_data;
+
+ dev_err(dev->dev, "initiating i2c bus recovery\n");
+ /* Send NACK to the slave */
+ flag = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
+ flag |= DAVINCI_I2C_MDR_NACK;
+ /* write the data into mode register */
+ davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
+ if (pdata)
+ generic_i2c_clock_pulse(pdata->scl_pin);
+ /* Send STOP */
+ flag = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
+ flag |= DAVINCI_I2C_MDR_STP;
+ davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
+}
+
+static inline void davinci_i2c_reset_ctrl(struct davinci_i2c_dev *i2c_dev,
+ int val)
+{
+ u16 w;
+
+ w = davinci_i2c_read_reg(i2c_dev, DAVINCI_I2C_MDR_REG);
+ if (!val) /* put I2C into reset */
+ w &= ~DAVINCI_I2C_MDR_IRS;
+ else /* take I2C out of reset */
+ w |= DAVINCI_I2C_MDR_IRS;
+
+ davinci_i2c_write_reg(i2c_dev, DAVINCI_I2C_MDR_REG, w);
+}
+
+static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev)
{
struct davinci_i2c_platform_data *pdata = dev->dev->platform_data;
u16 psc;
u32 clkh;
u32 clkl;
u32 input_clock = clk_get_rate(dev->clk);
- u16 w;
-
- if (!pdata)
- pdata = &davinci_i2c_platform_data_default;
-
- /* put I2C into reset */
- w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
- MOD_REG_BIT(w, DAVINCI_I2C_MDR_IRS, 0);
- davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
/* NOTE: I2C Clock divider programming info
* As per I2C specs the following formulas provide prescaler
davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKH_REG, clkh);
davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKL_REG, clkl);
+ dev_dbg(dev->dev, "input_clock = %d, CLK = %d\n", input_clock, clk);
+}
+
+/*
+ * This function configures I2C and brings I2C out of reset.
+ * This function is called during I2C init function. This function
+ * also gets called if I2C encounters any errors.
+ */
+static int i2c_davinci_init(struct davinci_i2c_dev *dev)
+{
+ struct davinci_i2c_platform_data *pdata = dev->dev->platform_data;
+
+ if (!pdata)
+ pdata = &davinci_i2c_platform_data_default;
+
+ /* put I2C into reset */
+ davinci_i2c_reset_ctrl(dev, 0);
+
+ /* compute clock dividers */
+ i2c_davinci_calc_clk_dividers(dev);
+
/* Respond at reserved "SMBus Host" slave address" (and zero);
* we seem to have no option to not respond...
*/
davinci_i2c_write_reg(dev, DAVINCI_I2C_OAR_REG, 0x08);
- dev_dbg(dev->dev, "input_clock = %d, CLK = %d\n", input_clock, clk);
dev_dbg(dev->dev, "PSC = %d\n",
davinci_i2c_read_reg(dev, DAVINCI_I2C_PSC_REG));
dev_dbg(dev->dev, "CLKL = %d\n",
pdata->bus_freq, pdata->bus_delay);
/* Take the I2C module out of reset: */
- w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
- MOD_REG_BIT(w, DAVINCI_I2C_MDR_IRS, 1);
- davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
+ davinci_i2c_reset_ctrl(dev, 1);
/* Enable interrupts */
davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, I2C_DAVINCI_INTR_ALL);
char allow_sleep)
{
unsigned long timeout;
+ static u16 to_cnt;
timeout = jiffies + dev->adapter.timeout;
while (davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG)
& DAVINCI_I2C_STR_BB) {
- if (time_after(jiffies, timeout)) {
- dev_warn(dev->dev,
- "timeout waiting for bus ready\n");
- return -ETIMEDOUT;
+ if (to_cnt <= DAVINCI_I2C_MAX_TRIES) {
+ if (time_after(jiffies, timeout)) {
+ dev_warn(dev->dev,
+ "timeout waiting for bus ready\n");
+ to_cnt++;
+ return -ETIMEDOUT;
+ } else {
+ to_cnt = 0;
+ i2c_recover_bus(dev);
+ i2c_davinci_init(dev);
+ }
}
if (allow_sleep)
schedule_timeout(1);
u16 w;
int r;
- if (msg->len == 0)
- return -EINVAL;
-
if (!pdata)
pdata = &davinci_i2c_platform_data_default;
/* Introduce a delay, required for some boards (e.g Davinci EVM) */
dev->buf = msg->buf;
dev->buf_len = msg->len;
+ dev->stop = stop;
davinci_i2c_write_reg(dev, DAVINCI_I2C_CNT_REG, dev->buf_len);
flag |= DAVINCI_I2C_MDR_TRX;
if (stop)
flag |= DAVINCI_I2C_MDR_STP;
+ if (msg->len == 0) {
+ flag |= DAVINCI_I2C_MDR_RM;
+ flag &= ~DAVINCI_I2C_MDR_STP;
+ }
/* Enable receive or transmit interrupts */
w = davinci_i2c_read_reg(dev, DAVINCI_I2C_IMR_REG);
if (msg->flags & I2C_M_RD)
- MOD_REG_BIT(w, DAVINCI_I2C_IMR_RRDY, 1);
+ w |= DAVINCI_I2C_IMR_RRDY;
else
- MOD_REG_BIT(w, DAVINCI_I2C_IMR_XRDY, 1);
+ w |= DAVINCI_I2C_IMR_XRDY;
davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, w);
dev->terminate = 0;
+
/* write the data into mode register */
davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
+ /*
+ * First byte should be set here, not after interrupt,
+ * because transmit-data-ready interrupt can come before
+ * NACK-interrupt during sending of previous message and
+ * ICDXR may have wrong data
+ */
+ if ((!(msg->flags & I2C_M_RD)) && dev->buf_len) {
+ davinci_i2c_write_reg(dev, DAVINCI_I2C_DXR_REG, *dev->buf++);
+ dev->buf_len--;
+ }
+
r = wait_for_completion_interruptible_timeout(&dev->cmd_complete,
dev->adapter.timeout);
if (r == 0) {
dev_err(dev->dev, "controller timed out\n");
+ i2c_recover_bus(dev);
i2c_davinci_init(dev);
dev->buf_len = 0;
return -ETIMEDOUT;
return msg->len;
if (stop) {
w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
- MOD_REG_BIT(w, DAVINCI_I2C_MDR_STP, 1);
+ w |= DAVINCI_I2C_MDR_STP;
davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
}
return -EREMOTEIO;
if (ret < 0)
return ret;
}
+
+#ifdef CONFIG_CPU_FREQ
+ complete(&dev->xfr_complete);
+#endif
+
return num;
}
static u32 i2c_davinci_func(struct i2c_adapter *adap)
{
- return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}
static void terminate_read(struct davinci_i2c_dev *dev)
case DAVINCI_I2C_IVR_ARDY:
davinci_i2c_write_reg(dev,
DAVINCI_I2C_STR_REG, DAVINCI_I2C_STR_ARDY);
+ if (((dev->buf_len == 0) && (dev->stop != 0)) ||
+ (dev->cmd_err & DAVINCI_I2C_STR_NACK)) {
+ w = davinci_i2c_read_reg(dev,
+ DAVINCI_I2C_MDR_REG);
+ w |= DAVINCI_I2C_MDR_STP;
+ davinci_i2c_write_reg(dev,
+ DAVINCI_I2C_MDR_REG, w);
+ }
complete(&dev->cmd_complete);
break;
w = davinci_i2c_read_reg(dev,
DAVINCI_I2C_IMR_REG);
- MOD_REG_BIT(w, DAVINCI_I2C_IMR_XRDY, 0);
+ w &= ~DAVINCI_I2C_IMR_XRDY;
davinci_i2c_write_reg(dev,
DAVINCI_I2C_IMR_REG,
w);
return count ? IRQ_HANDLED : IRQ_NONE;
}
+#ifdef CONFIG_CPU_FREQ
+static int i2c_davinci_cpufreq_transition(struct notifier_block *nb,
+ unsigned long val, void *data)
+{
+ struct davinci_i2c_dev *dev;
+
+ dev = container_of(nb, struct davinci_i2c_dev, freq_transition);
+ if (val == CPUFREQ_PRECHANGE) {
+ wait_for_completion(&dev->xfr_complete);
+ davinci_i2c_reset_ctrl(dev, 0);
+ } else if (val == CPUFREQ_POSTCHANGE) {
+ i2c_davinci_calc_clk_dividers(dev);
+ davinci_i2c_reset_ctrl(dev, 1);
+ }
+
+ return 0;
+}
+
+static inline int i2c_davinci_cpufreq_register(struct davinci_i2c_dev *dev)
+{
+ dev->freq_transition.notifier_call = i2c_davinci_cpufreq_transition;
+
+ return cpufreq_register_notifier(&dev->freq_transition,
+ CPUFREQ_TRANSITION_NOTIFIER);
+}
+
+static inline void i2c_davinci_cpufreq_deregister(struct davinci_i2c_dev *dev)
+{
+ cpufreq_unregister_notifier(&dev->freq_transition,
+ CPUFREQ_TRANSITION_NOTIFIER);
+}
+#else
+static inline int i2c_davinci_cpufreq_register(struct davinci_i2c_dev *dev)
+{
+ return 0;
+}
+
+static inline void i2c_davinci_cpufreq_deregister(struct davinci_i2c_dev *dev)
+{
+}
+#endif
+
static struct i2c_algorithm i2c_davinci_algo = {
.master_xfer = i2c_davinci_xfer,
.functionality = i2c_davinci_func,
}
init_completion(&dev->cmd_complete);
+#ifdef CONFIG_CPU_FREQ
+ init_completion(&dev->xfr_complete);
+#endif
dev->dev = get_device(&pdev->dev);
dev->irq = irq->start;
platform_set_drvdata(pdev, dev);
}
clk_enable(dev->clk);
- dev->base = (void __iomem *)IO_ADDRESS(mem->start);
+ dev->base = ioremap(mem->start, resource_size(mem));
+ if (!dev->base) {
+ r = -EBUSY;
+ goto err_mem_ioremap;
+ }
+
i2c_davinci_init(dev);
r = request_irq(dev->irq, i2c_davinci_isr, 0, pdev->name, dev);
goto err_unuse_clocks;
}
+ r = i2c_davinci_cpufreq_register(dev);
+ if (r) {
+ dev_err(&pdev->dev, "failed to register cpufreq\n");
+ goto err_free_irq;
+ }
+
adap = &dev->adapter;
i2c_set_adapdata(adap, dev);
adap->owner = THIS_MODULE;
err_free_irq:
free_irq(dev->irq, dev);
err_unuse_clocks:
+ iounmap(dev->base);
+err_mem_ioremap:
clk_disable(dev->clk);
clk_put(dev->clk);
dev->clk = NULL;
struct davinci_i2c_dev *dev = platform_get_drvdata(pdev);
struct resource *mem;
+ i2c_davinci_cpufreq_deregister(dev);
+
platform_set_drvdata(pdev, NULL);
i2c_del_adapter(&dev->adapter);
put_device(&pdev->dev);
davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, 0);
free_irq(IRQ_I2C, dev);
+ iounmap(dev->base);
kfree(dev);
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
return 0;
}
+#ifdef CONFIG_PM
+static int davinci_i2c_suspend(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct davinci_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
+
+ /* put I2C into reset */
+ davinci_i2c_reset_ctrl(i2c_dev, 0);
+ clk_disable(i2c_dev->clk);
+
+ return 0;
+}
+
+static int davinci_i2c_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct davinci_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
+
+ clk_enable(i2c_dev->clk);
+ /* take I2C out of reset */
+ davinci_i2c_reset_ctrl(i2c_dev, 1);
+
+ return 0;
+}
+
+static const struct dev_pm_ops davinci_i2c_pm = {
+ .suspend = davinci_i2c_suspend,
+ .resume = davinci_i2c_resume,
+};
+
+#define davinci_i2c_pm_ops (&davinci_i2c_pm)
+#else
+#define davinci_i2c_pm_ops NULL
+#endif
+
/* work with hotplug and coldplug */
MODULE_ALIAS("platform:i2c_davinci");
.driver = {
.name = "i2c_davinci",
.owner = THIS_MODULE,
+ .pm = davinci_i2c_pm_ops,
},
};
--- /dev/null
+/*
+ * linux/drivers/i2c/busses/i2c-nuc900.c
+ *
+ * Copyright (c) 2010 Nuvoton technology corporation.
+ *
+ * This driver based on S3C2410 I2C driver of Ben Dooks <ben-Y5A6D6n0/KfQXOPxS62xeg@public.gmane.org>.
+ * Written by Wan ZongShun <mcuos.com-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
+ *
+ * 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;version 2 of the License.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include <linux/i2c.h>
+#include <linux/i2c-id.h>
+#include <linux/init.h>
+#include <linux/time.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/cpufreq.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+
+#include <mach/mfp.h>
+#include <mach/i2c.h>
+
+/* nuc900 i2c registers offset */
+
+#define CSR 0x00
+#define DIVIDER 0x04
+#define CMDR 0x08
+#define SWR 0x0C
+#define RXR 0x10
+#define TXR 0x14
+
+/* nuc900 i2c CSR register bits */
+
+#define IRQEN 0x003
+#define I2CBUSY 0x400
+#define I2CSTART 0x018
+#define IRQFLAG 0x004
+#define ARBIT_LOST 0x200
+#define SLAVE_ACK 0x800
+
+/* nuc900 i2c CMDR register bits */
+
+#define I2C_CMD_START 0x10
+#define I2C_CMD_STOP 0x08
+#define I2C_CMD_READ 0x04
+#define I2C_CMD_WRITE 0x02
+#define I2C_CMD_NACK 0x01
+
+/* i2c controller state */
+
+enum nuc900_i2c_state {
+ STATE_IDLE,
+ STATE_START,
+ STATE_READ,
+ STATE_WRITE,
+ STATE_STOP
+};
+
+/* i2c controller private data */
+
+struct nuc900_i2c {
+ spinlock_t lock;
+ wait_queue_head_t wait;
+
+ struct i2c_msg *msg;
+ unsigned int msg_num;
+ unsigned int msg_idx;
+ unsigned int msg_ptr;
+ unsigned int irq;
+
+ enum nuc900_i2c_state state;
+
+ void __iomem *regs;
+ struct clk *clk;
+ struct device *dev;
+ struct resource *ioarea;
+ struct i2c_adapter adap;
+};
+
+/* nuc900_i2c_master_complete
+ *
+ * complete the message and wake up the caller, using the given return code,
+ * or zero to mean ok.
+*/
+
+static inline void nuc900_i2c_master_complete(struct nuc900_i2c *i2c, int ret)
+{
+ dev_dbg(i2c->dev, "master_complete %d\n", ret);
+
+ i2c->msg_ptr = 0;
+ i2c->msg = NULL;
+ i2c->msg_idx++;
+ i2c->msg_num = 0;
+ if (ret)
+ i2c->msg_idx = ret;
+
+ wake_up(&i2c->wait);
+}
+
+/* irq enable/disable functions */
+
+static inline void nuc900_i2c_disable_irq(struct nuc900_i2c *i2c)
+{
+ unsigned long tmp;
+
+ tmp = readl(i2c->regs + CSR);
+ writel(tmp & ~IRQEN, i2c->regs + CSR);
+}
+
+static inline void nuc900_i2c_enable_irq(struct nuc900_i2c *i2c)
+{
+ unsigned long tmp;
+
+ tmp = readl(i2c->regs + CSR);
+ writel(tmp | IRQEN, i2c->regs + CSR);
+}
+
+
+/* nuc900_i2c_message_start
+ *
+ * put the start of a message onto the bus
+*/
+
+static void nuc900_i2c_message_start(struct nuc900_i2c *i2c,
+ struct i2c_msg *msg)
+{
+ unsigned int addr = (msg->addr & 0x7f) << 1;
+
+ if (msg->flags & I2C_M_RD)
+ addr |= 0x1;
+ writel(addr & 0xff, i2c->regs + TXR);
+ writel(I2C_CMD_START | I2C_CMD_WRITE, i2c->regs + CMDR);
+}
+
+static inline void nuc900_i2c_stop(struct nuc900_i2c *i2c, int ret)
+{
+
+ dev_dbg(i2c->dev, "STOP\n");
+
+ /* stop the transfer */
+ i2c->state = STATE_STOP;
+ writel(I2C_CMD_STOP, i2c->regs + CMDR);
+
+ nuc900_i2c_master_complete(i2c, ret);
+ nuc900_i2c_disable_irq(i2c);
+}
+
+/* helper functions to determine the current state in the set of
+ * messages we are sending
+*/
+
+/* is_lastmsg()
+ *
+ * returns TRUE if the current message is the last in the set
+*/
+
+static inline int is_lastmsg(struct nuc900_i2c *i2c)
+{
+ return i2c->msg_idx >= (i2c->msg_num - 1);
+}
+
+/* is_msglast
+ *
+ * returns TRUE if we this is the last byte in the current message
+*/
+
+static inline int is_msglast(struct nuc900_i2c *i2c)
+{
+ return i2c->msg_ptr == i2c->msg->len-1;
+}
+
+/* is_msgend
+ *
+ * returns TRUE if we reached the end of the current message
+*/
+
+static inline int is_msgend(struct nuc900_i2c *i2c)
+{
+ return i2c->msg_ptr >= i2c->msg->len;
+}
+
+/* i2c_nuc900_irq_nextbyte
+ *
+ * process an interrupt and work out what to do
+ */
+
+static void i2c_nuc900_irq_nextbyte(struct nuc900_i2c *i2c,
+ unsigned long iicstat)
+{
+ unsigned char byte;
+
+ switch (i2c->state) {
+
+ case STATE_IDLE:
+ dev_err(i2c->dev, "%s: called in STATE_IDLE\n", __func__);
+ break;
+
+ case STATE_STOP:
+ dev_err(i2c->dev, "%s: called in STATE_STOP\n", __func__);
+ nuc900_i2c_disable_irq(i2c);
+ break;
+
+ case STATE_START:
+ /* last thing we did was send a start condition on the
+ * bus, or started a new i2c message
+ */
+
+ if (iicstat & SLAVE_ACK &&
+ !(i2c->msg->flags & I2C_M_IGNORE_NAK)) {
+ /* ack was not received... */
+
+ dev_dbg(i2c->dev, "ack was not received\n");
+ nuc900_i2c_stop(i2c, -ENXIO);
+ break;
+ }
+
+ if (i2c->msg->flags & I2C_M_RD)
+ i2c->state = STATE_READ;
+ else
+ i2c->state = STATE_WRITE;
+
+ /* terminate the transfer if there is nothing to do
+ * as this is used by the i2c probe to find devices.
+ */
+
+ if (is_lastmsg(i2c) && i2c->msg->len == 0) {
+ nuc900_i2c_stop(i2c, 0);
+ break;
+ }
+
+ if (i2c->state == STATE_READ)
+ goto prepare_read;
+
+ /* fall through to the write state, as we will need to
+ * send a byte as well
+ */
+
+ case STATE_WRITE:
+ /* we are writing data to the device... check for the
+ * end of the message, and if so, work out what to do
+ */
+
+ if (!(i2c->msg->flags & I2C_M_IGNORE_NAK)) {
+ if (iicstat & SLAVE_ACK) {
+ dev_dbg(i2c->dev, "WRITE: No Ack\n");
+
+ nuc900_i2c_stop(i2c, -ECONNREFUSED);
+ break;
+ }
+ }
+
+retry_write:
+
+ if (!is_msgend(i2c)) {
+ byte = i2c->msg->buf[i2c->msg_ptr++];
+ writeb(byte, i2c->regs + TXR);
+ writel(I2C_CMD_WRITE, i2c->regs + CMDR);
+
+ } else if (!is_lastmsg(i2c)) {
+ /* we need to go to the next i2c message */
+
+ dev_dbg(i2c->dev, "WRITE: Next Message\n");
+
+ i2c->msg_ptr = 0;
+ i2c->msg_idx++;
+ i2c->msg++;
+
+ /* check to see if we need to do another message */
+ if (i2c->msg->flags & I2C_M_NOSTART) {
+
+ if (i2c->msg->flags & I2C_M_RD) {
+ /* cannot do this, the controller
+ * forces us to send a new START
+ * when we change direction
+ */
+
+ nuc900_i2c_stop(i2c, -EINVAL);
+ }
+
+ goto retry_write;
+ } else {
+ /* send the new start */
+ nuc900_i2c_message_start(i2c, i2c->msg);
+ i2c->state = STATE_START;
+ }
+
+ } else {
+ /* send stop */
+
+ nuc900_i2c_stop(i2c, 0);
+ }
+ break;
+
+ case STATE_READ:
+ /* we have a byte of data in the data register, do
+ * something with it, and then work out wether we are
+ * going to do any more read/write
+ */
+
+ byte = readb(i2c->regs + RXR);
+ i2c->msg->buf[i2c->msg_ptr++] = byte;
+
+prepare_read:
+ if (is_msglast(i2c)) {
+ /* last byte of buffer */
+
+ if (is_lastmsg(i2c))
+ writel(I2C_CMD_READ | I2C_CMD_NACK,
+ i2c->regs + CMDR);
+
+ } else if (is_msgend(i2c)) {
+ /* ok, we've read the entire buffer, see if there
+ * is anything else we need to do
+ */
+
+ if (is_lastmsg(i2c)) {
+ /* last message, send stop and complete */
+ dev_dbg(i2c->dev, "READ: Send Stop\n");
+
+ nuc900_i2c_stop(i2c, 0);
+ } else {
+ /* go to the next transfer */
+ dev_dbg(i2c->dev, "READ: Next Transfer\n");
+
+ i2c->msg_ptr = 0;
+ i2c->msg_idx++;
+ i2c->msg++;
+
+ writel(I2C_CMD_READ, i2c->regs + CMDR);
+ }
+
+ } else {
+ writel(I2C_CMD_READ, i2c->regs + CMDR);
+ }
+
+ break;
+ }
+}
+
+/* nuc900_i2c_irq
+ *
+ * top level IRQ servicing routine
+*/
+
+static irqreturn_t nuc900_i2c_irq(int irqno, void *dev_id)
+{
+ struct nuc900_i2c *i2c = dev_id;
+ unsigned long status;
+
+ status = readl(i2c->regs + CSR);
+ writel(status | IRQFLAG, i2c->regs + CSR);
+
+ if (status & ARBIT_LOST) {
+ /* deal with arbitration loss */
+ dev_err(i2c->dev, "deal with arbitration loss\n");
+ goto out;
+ }
+
+ if (i2c->state == STATE_IDLE) {
+ dev_dbg(i2c->dev, "IRQ: error i2c->state == IDLE\n");
+ goto out;
+ }
+
+ /* pretty much this leaves us with the fact that we've
+ * transmitted or received whatever byte we last sent
+ */
+
+ i2c_nuc900_irq_nextbyte(i2c, status);
+
+ out:
+ return IRQ_HANDLED;
+}
+
+
+/* nuc900_i2c_set_master
+ *
+ * get the i2c bus for a master transaction
+*/
+
+static int nuc900_i2c_set_master(struct nuc900_i2c *i2c)
+{
+ int timeout = 400;
+
+ while (timeout-- > 0) {
+ if (((readl(i2c->regs + SWR) & I2CSTART) == I2CSTART) &&
+ ((readl(i2c->regs + CSR) & I2CBUSY) == 0)) {
+ return 0;
+ }
+
+ msleep(1);
+ }
+
+ return -ETIMEDOUT;
+}
+
+/* nuc900_i2c_doxfer
+ *
+ * this starts an i2c transfer
+*/
+
+static int nuc900_i2c_doxfer(struct nuc900_i2c *i2c,
+ struct i2c_msg *msgs, int num)
+{
+ unsigned long iicstat, timeout;
+ int spins = 20;
+ int ret;
+
+ ret = nuc900_i2c_set_master(i2c);
+ if (ret != 0) {
+ dev_err(i2c->dev, "cannot get bus (error %d)\n", ret);
+ ret = -EAGAIN;
+ goto out;
+ }
+
+ spin_lock_irq(&i2c->lock);
+
+ i2c->msg = msgs;
+ i2c->msg_num = num;
+ i2c->msg_ptr = 0;
+ i2c->msg_idx = 0;
+ i2c->state = STATE_START;
+
+ nuc900_i2c_message_start(i2c, msgs);
+ spin_unlock_irq(&i2c->lock);
+
+ timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
+
+ ret = i2c->msg_idx;
+
+ /* having these next two as dev_err() makes life very
+ * noisy when doing an i2cdetect
+ */
+
+ if (timeout == 0)
+ dev_dbg(i2c->dev, "timeout\n");
+ else if (ret != num)
+ dev_dbg(i2c->dev, "incomplete xfer (%d)\n", ret);
+
+ /* ensure the stop has been through the bus */
+
+ dev_dbg(i2c->dev, "waiting for bus idle\n");
+
+ /* first, try busy waiting briefly */
+ do {
+ iicstat = readl(i2c->regs + CSR);
+ } while ((iicstat & I2CBUSY) && --spins);
+
+ /* if that timed out sleep */
+ if (!spins) {
+ msleep(1);
+ iicstat = readl(i2c->regs + CSR);
+ }
+
+ if (iicstat & I2CBUSY)
+ dev_warn(i2c->dev, "timeout waiting for bus idle\n");
+
+ out:
+ return ret;
+}
+
+/* nuc900_i2c_xfer
+ *
+ * first port of call from the i2c bus code when an message needs
+ * transferring across the i2c bus.
+*/
+
+static int nuc900_i2c_xfer(struct i2c_adapter *adap,
+ struct i2c_msg *msgs, int num)
+{
+ struct nuc900_i2c *i2c = (struct nuc900_i2c *)adap->algo_data;
+ int retry;
+ int ret;
+
+ nuc900_i2c_enable_irq(i2c);
+
+ for (retry = 0; retry < adap->retries; retry++) {
+
+ ret = nuc900_i2c_doxfer(i2c, msgs, num);
+
+ if (ret != -EAGAIN)
+ return ret;
+
+ dev_dbg(i2c->dev, "Retrying transmission (%d)\n", retry);
+
+ udelay(100);
+ }
+
+ return -EREMOTEIO;
+}
+
+/* declare our i2c functionality */
+static u32 nuc900_i2c_func(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING;
+}
+
+/* i2c bus registration info */
+
+static const struct i2c_algorithm nuc900_i2c_algorithm = {
+ .master_xfer = nuc900_i2c_xfer,
+ .functionality = nuc900_i2c_func,
+};
+
+/* nuc900_i2c_probe
+ *
+ * called by the bus driver when a suitable device is found
+*/
+
+static int __devinit nuc900_i2c_probe(struct platform_device *pdev)
+{
+ struct nuc900_i2c *i2c;
+ struct nuc900_platform_i2c *pdata;
+ struct resource *res;
+ int ret;
+
+ pdata = pdev->dev.platform_data;
+ if (!pdata) {
+ dev_err(&pdev->dev, "no platform data\n");
+ return -EINVAL;
+ }
+
+ i2c = kzalloc(sizeof(struct nuc900_i2c), GFP_KERNEL);
+ if (!i2c) {
+ dev_err(&pdev->dev, "no memory for state\n");
+ return -ENOMEM;
+ }
+
+ strlcpy(i2c->adap.name, "nuc900-i2c0", sizeof(i2c->adap.name));
+ i2c->adap.owner = THIS_MODULE;
+ i2c->adap.algo = &nuc900_i2c_algorithm;
+ i2c->adap.retries = 2;
+ i2c->adap.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
+
+ spin_lock_init(&i2c->lock);
+ init_waitqueue_head(&i2c->wait);
+
+ /* find the clock and enable it */
+
+ i2c->dev = &pdev->dev;
+ i2c->clk = clk_get(&pdev->dev, NULL);
+ if (IS_ERR(i2c->clk)) {
+ dev_err(&pdev->dev, "cannot get clock\n");
+ ret = -ENOENT;
+ goto err_noclk;
+ }
+
+ dev_dbg(&pdev->dev, "clock source %p\n", i2c->clk);
+
+ clk_enable(i2c->clk);
+
+ /* map the registers */
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (res == NULL) {
+ dev_err(&pdev->dev, "cannot find IO resource\n");
+ ret = -ENOENT;
+ goto err_clk;
+ }
+
+ i2c->ioarea = request_mem_region(res->start, resource_size(res),
+ pdev->name);
+
+ if (i2c->ioarea == NULL) {
+ dev_err(&pdev->dev, "cannot request IO\n");
+ ret = -ENXIO;
+ goto err_clk;
+ }
+
+ i2c->regs = ioremap(res->start, resource_size(res));
+
+ if (i2c->regs == NULL) {
+ dev_err(&pdev->dev, "cannot map IO\n");
+ ret = -ENXIO;
+ goto err_ioarea;
+ }
+
+ dev_dbg(&pdev->dev, "registers %p (%p, %p)\n",
+ i2c->regs, i2c->ioarea, res);
+
+ /* setup info block for the i2c core */
+
+ i2c->adap.algo_data = i2c;
+ i2c->adap.dev.parent = &pdev->dev;
+
+ mfp_set_groupg(&pdev->dev);
+
+ clk_get_rate(i2c->clk);
+
+ ret = (i2c->clk.apbfreq)/(pdata->bus_freq * 5) - 1;
+ writel(ret & 0xffff, i2c->regs + DIVIDER);
+
+ /* find the IRQ for this unit (note, this relies on the init call to
+ * ensure no current IRQs pending
+ */
+
+ i2c->irq = ret = platform_get_irq(pdev, 0);
+ if (ret <= 0) {
+ dev_err(&pdev->dev, "cannot find IRQ\n");
+ goto err_iomap;
+ }
+
+ ret = request_irq(i2c->irq, nuc900_i2c_irq, IRQF_DISABLED | IRQF_SHARED,
+ dev_name(&pdev->dev), i2c);
+
+ if (ret != 0) {
+ dev_err(&pdev->dev, "cannot claim IRQ %d\n", i2c->irq);
+ goto err_iomap;
+ }
+
+ /* Note, previous versions of the driver used i2c_add_adapter()
+ * to add the bus at any number. We now pass the bus number via
+ * the platform data, so if unset it will now default to always
+ * being bus 0.
+ */
+
+ i2c->adap.nr = pdata->bus_num;
+
+ ret = i2c_add_numbered_adapter(&i2c->adap);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to add bus to i2c core\n");
+ goto err_irq;
+ }
+
+ platform_set_drvdata(pdev, i2c);
+
+ dev_info(&pdev->dev, "%s: NUC900 I2C adapter\n",
+ dev_name(&i2c->adap.dev));
+ return 0;
+
+ err_irq:
+ free_irq(i2c->irq, i2c);
+
+ err_iomap:
+ iounmap(i2c->regs);
+
+ err_ioarea:
+ release_resource(i2c->ioarea);
+ kfree(i2c->ioarea);
+
+ err_clk:
+ clk_disable(i2c->clk);
+ clk_put(i2c->clk);
+
+ err_noclk:
+ kfree(i2c);
+ return ret;
+}
+
+/* nuc900_i2c_remove
+ *
+ * called when device is removed from the bus
+*/
+
+static int __devexit nuc900_i2c_remove(struct platform_device *pdev)
+{
+ struct nuc900_i2c *i2c = platform_get_drvdata(pdev);
+
+ i2c_del_adapter(&i2c->adap);
+ free_irq(i2c->irq, i2c);
+
+ clk_disable(i2c->clk);
+ clk_put(i2c->clk);
+
+ iounmap(i2c->regs);
+
+ release_resource(i2c->ioarea);
+ kfree(i2c->ioarea);
+ kfree(i2c);
+
+ return 0;
+}
+
+static struct platform_driver nuc900_i2c_driver = {
+ .probe = nuc900_i2c_probe,
+ .remove = __devexit_p(nuc900_i2c_remove),
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "nuc900-i2c0",
+ },
+};
+
+static int __init i2c_adap_nuc900_init(void)
+{
+ return platform_driver_register(&nuc900_i2c_driver);
+}
+
+static void __exit i2c_adap_nuc900_exit(void)
+{
+ platform_driver_unregister(&nuc900_i2c_driver);
+}
+subsys_initcall(i2c_adap_nuc900_init);
+module_exit(i2c_adap_nuc900_exit);
+
+MODULE_DESCRIPTION("NUC900 I2C Bus driver");
+MODULE_AUTHOR("Wan ZongShun, <mcuos.com-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:nuc900-i2c0");
struct pxa_i2c *i2c;
struct resource *res;
struct i2c_pxa_platform_data *plat = dev->dev.platform_data;
- struct platform_device_id *id = platform_get_device_id(dev);
+ const struct platform_device_id *id = platform_get_device_id(dev);
int ret;
int irq;
projects / karo-tx-linux.git / commitdiff