Add suspend/resume and cpufreq features to DaVinci I2C driver
All patches apply to Linus' kernel tree.
Testing of these features was done on DA850/OMAP-L138 EVM.
Chaithrika U S (4):
i2c: davinci: Remove MOD_REG_BIT and IO_ADDRESS usage
i2c: davinci: Add helper functions
i2c: davinci: Add suspend/resume support
i2c: davinci: Add cpufreq support
drivers/i2c/busses/i2c-davinci.c | 228 ++++++++++++++++++++++++++++---------
1 files changed, 172 insertions(+), 56 deletions(-)
In this version, the suspend/resume support patch has been updated to
use dev_pm_ops.
Add cpufreq support for DaVinci I2C driver.
Tested on DA850/OMAP-L138 EVM. For the purpose of testing, the patches
which add cpufreq support [1] for this SoC are needed.
[1]http://linux.davincidsp.com/pipermail/davinci-linux-open-source/
2009-September/016118.html
Signed-off-by: Chaithrika U S <[email protected]>
Signed-off-by: Kevin Hilman <[email protected]>
---
drivers/i2c/busses/i2c-davinci.c | 63 ++++++++++++++++++++++++++++++++++++++
1 files changed, 63 insertions(+), 0 deletions(-)
diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index d2a4844..773cce5 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -35,6 +35,7 @@
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/io.h>
+#include <linux/cpufreq.h>
#include <mach/hardware.h>
#include <mach/i2c.h>
@@ -105,6 +106,10 @@ struct davinci_i2c_dev {
int irq;
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 */
@@ -375,6 +380,11 @@ 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;
}
@@ -499,6 +509,48 @@ 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,
@@ -538,6 +590,9 @@ 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);
@@ -563,6 +618,12 @@ 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;
@@ -604,6 +665,8 @@ 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);
--
1.5.6
Add i2c reset control and clock divider calculation functions
which will be useful for power management features.
Signed-off-by: Chaithrika U S <[email protected]>
Signed-off-by: Kevin Hilman <[email protected]>
---
drivers/i2c/busses/i2c-davinci.c | 56 +++++++++++++++++++++++++-------------
1 files changed, 37 insertions(+), 19 deletions(-)
diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index 44a3cb3..81c1049 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -124,12 +124,21 @@ 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.
- */
-static int i2c_davinci_init(struct davinci_i2c_dev *dev)
+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;
@@ -138,15 +147,6 @@ 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);
- w &= ~DAVINCI_I2C_MDR_IRS;
- 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
@@ -178,12 +178,32 @@ 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",
@@ -194,9 +214,7 @@ 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);
- w |= DAVINCI_I2C_MDR_IRS;
- 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);
--
1.5.6
Add suspend and resume callbacks to DaVinci I2C driver.
This has been tested on DA850/OMAP-L138 EVM. The SoC specific
suspend-to-RAM support patch series [1] is needed to test this feature.
[1] http://linux.davincidsp.com/pipermail/davinci-linux-open-source/
2009-November/016958.html
Signed-off-by: Chaithrika U S <[email protected]>
Signed-off-by: Kevin Hilman <[email protected]>
---
drivers/i2c/busses/i2c-davinci.c | 36 ++++++++++++++++++++++++++++++++++++
1 files changed, 36 insertions(+), 0 deletions(-)
diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index 81c1049..d2a4844 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -622,6 +622,41 @@ 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 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");
@@ -631,6 +666,7 @@ static struct platform_driver davinci_i2c_driver = {
.driver = {
.name = "i2c_davinci",
.owner = THIS_MODULE,
+ .pm = davinci_i2c_pm_ops,
},
};
--
1.5.6
Cleanup the DaVinci I2C driver. Remove MOD_REG_BIT macro.
Also use ioremap instead of IO_ADDRESS macro.
Signed-off-by: Chaithrika U S <[email protected]>
Signed-off-by: Kevin Hilman <[email protected]>
---
drivers/i2c/busses/i2c-davinci.c | 77 +++++++++++++++++++-------------------
1 files changed, 38 insertions(+), 39 deletions(-)
diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index c89687a..44a3cb3 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -37,7 +37,6 @@
#include <linux/io.h>
#include <mach/hardware.h>
-
#include <mach/i2c.h>
/* ----- global defines ----------------------------------------------- */
@@ -71,37 +70,29 @@
#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_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;
@@ -154,7 +145,7 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev)
/* put I2C into reset */
w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
- MOD_REG_BIT(w, DAVINCI_I2C_MDR_IRS, 0);
+ w &= ~DAVINCI_I2C_MDR_IRS;
davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
/* NOTE: I2C Clock divider programming info
@@ -204,7 +195,7 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev)
/* 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);
+ w |= DAVINCI_I2C_MDR_IRS;
davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
/* Enable interrupts */
@@ -284,9 +275,9 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
/* 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;
@@ -333,7 +324,7 @@ 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;
@@ -461,7 +452,7 @@ 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);
@@ -540,7 +531,12 @@ 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);
@@ -570,6 +566,8 @@ 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;
@@ -598,6 +596,7 @@ 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);
--
1.5.6