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Merge branch 'for-linus/i2c-2636' of git://git.fluff.org/bjdooks/linux

Browse Source 
* 'for-linus/i2c-2636' of git://git.fluff.org/bjdooks/linux:
  i2c/nuc900: add i2c driver support for nuc900
  i2c: Enable NXP LPC support in Kconfig
  i2c-pxa: fix compiler warning, due to missing const
  i2c: davinci: bus recovery procedure to clear the bus
  i2c: davinci: Add cpufreq support
  i2c: davinci: Add suspend/resume support
  i2c: davinci: Add helper functions for power management
  i2c: davinci: misc. cleanups: remove MOD_REG_BIT and IO_ADDRESS usage
  i2c: davinci: Fix smbus Oops with AIC33 usage
This commit is contained in:
Linus Torvalds 2010-08-14 11:57:54 -07:00
commit d0a0c28cf1
6 changed files with 978 additions and 64 deletions
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9
arch/arm/mach-w90x900/include/mach/i2c.h Normal file
View File

@ -0,0 +1,9 @@
#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 */

11
drivers/i2c/busses/Kconfig
View File

@ -448,6 +448,13 @@ config I2C_NOMADIK
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
@ -496,8 +503,8 @@ config I2C_PMCMSP
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

1
drivers/i2c/busses/Makefile
View File

@ -43,6 +43,7 @@ obj-$(CONFIG_I2C_IXP2000) += i2c-ixp2000.o
obj-$(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

310
drivers/i2c/busses/i2c-davinci.c
View File

@ -36,14 +36,16 @@
#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 | \
@ -72,37 +74,29 @@
#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_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 (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_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 (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_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;
@ -113,8 +107,13 @@ struct davinci_i2c_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 */
@ -134,12 +133,59 @@ static inline u16 davinci_i2c_read_reg(struct davinci_i2c_dev *i2c_dev, int reg)
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;
@ -148,15 +194,6 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev)
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
@ -188,12 +225,32 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev)
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",
@ -204,9 +261,7 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev)
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);
@ -221,14 +276,22 @@ static int i2c_davinci_wait_bus_not_busy(struct davinci_i2c_dev *dev,
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);
@ -250,9 +313,6 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
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) */
@ -264,6 +324,7 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
dev->buf = msg->buf;
dev->buf_len = msg->len;
dev->stop = stop;
davinci_i2c_write_reg(dev, DAVINCI_I2C_CNT_REG, dev->buf_len);
@ -281,23 +342,40 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
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;
@ -334,7 +412,7 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
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;
@ -367,12 +445,17 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
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)
@ -431,6 +514,14 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id)
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;
@ -462,7 +553,7 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id)
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);
@ -491,6 +582,48 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id)
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,
@ -530,6 +663,9 @@ static int davinci_i2c_probe(struct platform_device *pdev)
}
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);
@ -541,7 +677,12 @@ static int davinci_i2c_probe(struct platform_device *pdev)
}
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);
@ -550,6 +691,12 @@ static int davinci_i2c_probe(struct platform_device *pdev)
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;
@ -571,6 +718,8 @@ static int davinci_i2c_probe(struct platform_device *pdev)
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;
@ -589,6 +738,8 @@ static int davinci_i2c_remove(struct platform_device *pdev)
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);
@ -599,6 +750,7 @@ static int davinci_i2c_remove(struct platform_device *pdev)
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);
@ -606,6 +758,41 @@ static int davinci_i2c_remove(struct platform_device *pdev)
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");
@ -615,6 +802,7 @@ static struct platform_driver davinci_i2c_driver = {
.driver = {
.name = "i2c_davinci",
.owner = THIS_MODULE,
.pm = davinci_i2c_pm_ops,
},
};

709
drivers/i2c/busses/i2c-nuc900.c Normal file
View File

@ -0,0 +1,709 @@
/*
* 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");

2
drivers/i2c/busses/i2c-pxa.c
View File

@ -1001,7 +1001,7 @@ static int i2c_pxa_probe(struct platform_device *dev)
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;