Hello Konstantin,
On Fri, May 25, 2012 at 08:39:09PM +0400, Konstantin Baydarov wrote:
> Hi.
> On 05/25/2012 12:25 PM, Eduardo Valentin wrote:
> > In the System Control Module, OMAP supplies a voltage reference
> > and a temperature sensor feature that are gathered in the band
> > gap voltage and temperature sensor (VBGAPTS) module. The band
> > gap provides current and voltage reference for its internal
> > circuits and other analog IP blocks. The analog-to-digital
> > converter (ADC) produces an output value that is proportional
> > to the silicon temperature.
> >
> > This patch provides a platform driver which expose this feature.
> > It is moduled as a MFD child of the System Control Module core
> > MFD driver.
> >
> > This driver provides only APIs to access the device properties,
> > like temperature, thresholds and update rate.
> >
> > Signed-off-by: Eduardo Valentin <eduardo.valentin@xxxxxx>
> > Signed-off-by: Keerthy <j-keerthy@xxxxxx>
> > ---
> > .../devicetree/bindings/thermal/omap_bandgap.txt | 27 +
> > drivers/thermal/Kconfig | 13 +
> > drivers/thermal/Makefile | 4 +-
> > drivers/thermal/omap-bandgap.c | 1601 ++++++++++++++++++++
> > drivers/thermal/omap-bandgap.h | 63 +
> > 5 files changed, 1707 insertions(+), 1 deletions(-)
> > create mode 100644 Documentation/devicetree/bindings/thermal/omap_bandgap.txt
> > create mode 100644 drivers/thermal/omap-bandgap.c
> > create mode 100644 drivers/thermal/omap-bandgap.h
> >
> >
> Add private spin lock in omap-bandgap driver to prevent blocking of
> control module general registers access.
Thanks for sending this out. I will rethink these drivers wrt to locking and will
your proposal.
> I wasn't able to test - I have panda 4430 board.
Right, we definetly need to have it probing on 4430, I will check how we can close on that.
>
> TODO:
> Prevent over-usage of spin_lock/spin_unlock for sequential calls of
> bg_writel().
OK...
>
> Signed-off-by: Konstantin Baydarov <kbaidarov@xxxxxxxxxxxxx>
>
> Index: omap-thermal/drivers/mfd/omap-control-core.c
> ===================================================================
> --- omap-thermal.orig/drivers/mfd/omap-control-core.c
> +++ omap-thermal/drivers/mfd/omap-control-core.c
> @@ -67,6 +67,19 @@ EXPORT_SYMBOL_GPL(omap_control_readl);
> int omap_control_writel(struct device *dev, u32 val, u32 reg)
> {
> struct omap_control *omap_control = dev_get_drvdata(dev);
> +
> + if (!omap_control)
> + return -EINVAL;
> +
> + writel(val, omap_control->base + reg);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(omap_control_writel);
> +
> +int omap_control_lock_writel(struct device *dev, u32 val, u32 reg)
> +{
> + struct omap_control *omap_control = dev_get_drvdata(dev);
> unsigned long flags;
>
> if (!omap_control)
> @@ -78,7 +91,7 @@ int omap_control_writel(struct device *d
>
> return 0;
> }
> -EXPORT_SYMBOL_GPL(omap_control_writel);
> +EXPORT_SYMBOL_GPL(omap_control_lock_writel);
>
> /**
> * omap_control_get: returns the control module device pinter
> @@ -136,6 +149,9 @@ static int __devinit omap_control_probe(
> struct device_node *np = dev->of_node;
> struct omap_control *omap_control;
>
> + printk("\n\t\t **** omap_control_probe(): enter ");
> + dump_stack();
> +
> omap_control = devm_kzalloc(dev, sizeof(*omap_control), GFP_KERNEL);
> if (!omap_control) {
> dev_err(dev, "not enough memory for omap_control\n");
> Index: omap-thermal/drivers/thermal/omap-bandgap.c
> ===================================================================
> --- omap-thermal.orig/drivers/thermal/omap-bandgap.c
> +++ omap-thermal/drivers/thermal/omap-bandgap.c
> @@ -154,6 +154,7 @@ struct temp_sensor_registers {
> u32 status_cold_mask;
>
> u32 bgap_efuse;
> + spinlock_t bg_reg_lock;
Indeed. I agree we should have this per sensor. Need to revisit the existing mutex as well though.
> };
>
> /**
> @@ -579,6 +580,17 @@ omap5430_adc_to_temp[OMAP5430_ADC_END_VA
> 124600, 124900, 125000, 125000, 125000, 125000,
> };
>
> +static int bg_writel(struct device *dev, u32 val, u32 reg, spinlock_t *lock)
> +{
> + unsigned long flags;
> + int ret;
> +
> + spin_lock_irqsave(lock, flags);
> + ret = omap_control_writel(dev, val, reg);
> + spin_unlock_irqrestore(lock, flags);
In fact this doesn't help much in the bulk writes case. As you have already mentioned,
ideally we should lock, perform the operation, then unlock, instead of several
lock/write/unlock sequences.
> + return ret;
> +}
> +
> static irqreturn_t talert_irq_handler(int irq, void *data)
> {
> struct omap_bandgap *bg_ptr = data;
> @@ -615,7 +627,7 @@ static irqreturn_t talert_irq_handler(in
> ctrl |= tsr->mask_hot_mask;
> }
>
> - r |= omap_control_writel(cdev, ctrl, tsr->bgap_mask_ctrl);
> + r |= bg_writel(cdev, ctrl, tsr->bgap_mask_ctrl, &tsr->bg_reg_lock);
>
> if (r) {
> dev_err(bg_ptr->dev, "failed to ack talert interrupt\n");
> @@ -705,7 +717,7 @@ static int temp_sensor_unmask_interrupts
> reg_val |= tsr->mask_cold_mask;
> else
> reg_val &= ~tsr->mask_cold_mask;
> - err |= omap_control_writel(cdev, reg_val, tsr->bgap_mask_ctrl);
> + err |= bg_writel(cdev, reg_val, tsr->bgap_mask_ctrl, &tsr->bg_reg_lock);
>
> if (err) {
> dev_err(bg_ptr->dev, "failed to unmask interrupts\n");
> @@ -751,14 +763,14 @@ int temp_sensor_configure_thot(struct om
> /* write the new t_cold value */
> reg_val = thresh_val & (~tsr->threshold_tcold_mask);
> reg_val |= cold << __ffs(tsr->threshold_tcold_mask);
> - err |= omap_control_writel(cdev, reg_val, tsr->bgap_threshold);
> + err |= bg_writel(cdev, reg_val, tsr->bgap_threshold, &tsr->bg_reg_lock);
> thresh_val = reg_val;
> }
>
> /* write the new t_hot value */
> reg_val = thresh_val & ~tsr->threshold_thot_mask;
> reg_val |= (t_hot << __ffs(tsr->threshold_thot_mask));
> - err |= omap_control_writel(cdev, reg_val, tsr->bgap_threshold);
> + err |= bg_writel(cdev, reg_val, tsr->bgap_threshold, &tsr->bg_reg_lock);
> if (err) {
> dev_err(bg_ptr->dev, "failed to reprogram thot threshold\n");
> return -EIO;
> @@ -782,7 +794,7 @@ int temp_sensor_init_talert_thresholds(s
> /* write the new t_cold value */
> reg_val = thresh_val & ~tsr->threshold_tcold_mask;
> reg_val |= (t_cold << __ffs(tsr->threshold_tcold_mask));
> - err |= omap_control_writel(cdev, reg_val, tsr->bgap_threshold);
> + err |= bg_writel(cdev, reg_val, tsr->bgap_threshold, &tsr->bg_reg_lock);
> if (err) {
> dev_err(bg_ptr->dev, "failed to reprogram tcold threshold\n");
> return -EIO;
> @@ -793,7 +805,7 @@ int temp_sensor_init_talert_thresholds(s
> /* write the new t_hot value */
> reg_val = thresh_val & ~tsr->threshold_thot_mask;
> reg_val |= (t_hot << __ffs(tsr->threshold_thot_mask));
> - err |= omap_control_writel(cdev, reg_val, tsr->bgap_threshold);
> + err |= bg_writel(cdev, reg_val, tsr->bgap_threshold, &tsr->bg_reg_lock);
> if (err) {
> dev_err(bg_ptr->dev, "failed to reprogram thot threshold\n");
> return -EIO;
> @@ -802,7 +814,7 @@ int temp_sensor_init_talert_thresholds(s
> err = omap_control_readl(cdev, tsr->bgap_mask_ctrl, ®_val);
> reg_val |= tsr->mask_hot_mask;
> reg_val |= tsr->mask_cold_mask;
> - err |= omap_control_writel(cdev, reg_val, tsr->bgap_mask_ctrl);
> + err |= bg_writel(cdev, reg_val, tsr->bgap_mask_ctrl, &tsr->bg_reg_lock);
> if (err) {
> dev_err(bg_ptr->dev, "failed to reprogram thot threshold\n");
> return -EIO;
> @@ -833,14 +845,14 @@ int temp_sensor_configure_tcold(struct o
> /* write the new t_hot value */
> reg_val = thresh_val & (~tsr->threshold_thot_mask);
> reg_val |= hot << __ffs(tsr->threshold_thot_mask);
> - err |= omap_control_writel(cdev, reg_val, tsr->bgap_threshold);
> + err |= bg_writel(cdev, reg_val, tsr->bgap_threshold, &tsr->bg_reg_lock);
> thresh_val = reg_val;
> }
>
> /* write the new t_cold value */
> reg_val = thresh_val & ~tsr->threshold_tcold_mask;
> reg_val |= (t_cold << __ffs(tsr->threshold_tcold_mask));
> - err |= omap_control_writel(cdev, reg_val, tsr->bgap_threshold);
> + err |= bg_writel(cdev, reg_val, tsr->bgap_threshold, &tsr->bg_reg_lock);
> if (err) {
> dev_err(bg_ptr->dev, "failed to reprogram tcold threshold\n");
> return -EIO;
> @@ -861,7 +873,7 @@ static int temp_sensor_configure_tshut_h
> err = omap_control_readl(cdev, tsr->tshut_threshold, ®_val);
> reg_val &= ~tsr->tshut_hot_mask;
> reg_val |= tshut_hot << __ffs(tsr->tshut_hot_mask);
> - err |= omap_control_writel(cdev, reg_val, tsr->tshut_threshold);
> + err |= bg_writel(cdev, reg_val, tsr->tshut_threshold, &tsr->bg_reg_lock);
> if (err) {
> dev_err(bg_ptr->dev, "failed to reprogram tshut thot\n");
> return -EIO;
> @@ -882,7 +894,7 @@ static int temp_sensor_configure_tshut_c
> err = omap_control_readl(cdev, tsr->tshut_threshold, ®_val);
> reg_val &= ~tsr->tshut_cold_mask;
> reg_val |= tshut_cold << __ffs(tsr->tshut_cold_mask);
> - err |= omap_control_writel(cdev, reg_val, tsr->tshut_threshold);
> + err |= bg_writel(cdev, reg_val, tsr->tshut_threshold, &tsr->bg_reg_lock);
> if (err) {
> dev_err(bg_ptr->dev, "failed to reprogram tshut tcold\n");
> return -EIO;
> @@ -903,7 +915,7 @@ static int configure_temp_sensor_counter
> err = omap_control_readl(cdev, tsr->bgap_counter, &val);
> val &= ~tsr->counter_mask;
> val |= counter << __ffs(tsr->counter_mask);
> - err |= omap_control_writel(cdev, val, tsr->bgap_counter);
> + err |= bg_writel(cdev, val, tsr->bgap_counter, &tsr->bg_reg_lock);
> if (err) {
> dev_err(bg_ptr->dev, "failed to reprogram tshut tcold\n");
> return -EIO;
> @@ -1124,7 +1136,7 @@ static int enable_continuous_mode(struct
> tsr = bg_ptr->pdata->sensors[i].registers;
> r = omap_control_readl(cdev, tsr->bgap_mode_ctrl, &val);
> val |= 1 << __ffs(tsr->mode_ctrl_mask);
> - r |= omap_control_writel(cdev, val, tsr->bgap_mode_ctrl);
> + r |= bg_writel(cdev, val, tsr->bgap_mode_ctrl, &tsr->bg_reg_lock);
> if (r)
> dev_err(bg_ptr->dev, "could not save sensor %d\n", i);
> }
> @@ -1342,6 +1354,9 @@ int __devinit omap_bandgap_probe(struct
> u32 val;
>
> tsr = bg_ptr->pdata->sensors[i].registers;
> + /* Initialize register lock */
> + spin_lock_init(&tsr->bg_reg_lock);
> +
> /*
> * check if the efuse has a non-zero value if not
> * it is an untrimmed sample and the temperatures
> @@ -1482,12 +1497,12 @@ omap_bandgap_force_single_read(struct om
> /* Select single conversion mode */
> err = omap_control_readl(cdev, tsr->bgap_mode_ctrl, &temp);
> temp &= ~(1 << __ffs(tsr->mode_ctrl_mask));
> - omap_control_writel(cdev, temp, tsr->bgap_mode_ctrl);
> + bg_writel(cdev, temp, tsr->bgap_mode_ctrl, &tsr->bg_reg_lock);
>
> /* Start of Conversion = 1 */
> err |= omap_control_readl(cdev, tsr->temp_sensor_ctrl, &temp);
> temp |= 1 << __ffs(tsr->bgap_soc_mask);
> - omap_control_writel(cdev, temp, tsr->temp_sensor_ctrl);
> + bg_writel(cdev, temp, tsr->temp_sensor_ctrl, &tsr->bg_reg_lock);
> /* Wait until DTEMP is updated */
> err |= omap_control_readl(cdev, tsr->temp_sensor_ctrl, &temp);
> temp &= (tsr->bgap_dtemp_mask);
> @@ -1498,7 +1513,7 @@ omap_bandgap_force_single_read(struct om
> /* Start of Conversion = 0 */
> err |= omap_control_readl(cdev, tsr->temp_sensor_ctrl, &temp);
> temp &= ~(1 << __ffs(tsr->bgap_soc_mask));
> - err |= omap_control_writel(cdev, temp, tsr->temp_sensor_ctrl);
> + err |= bg_writel(cdev, temp, tsr->temp_sensor_ctrl, &tsr->bg_reg_lock);
>
> return err ? -EIO : 0;
> }
> @@ -1519,20 +1534,20 @@ static int omap_bandgap_restore_ctxt(str
>
> err = omap_control_readl(cdev, tsr->bgap_counter, &val);
> if (val == 0) {
> - err |= omap_control_writel(cdev, rval->bg_threshold,
> - tsr->bgap_threshold);
> - err |= omap_control_writel(cdev, rval->tshut_threshold,
> - tsr->tshut_threshold);
> + err |= bg_writel(cdev, rval->bg_threshold,
> + tsr->bgap_threshold, &tsr->bg_reg_lock);
> + err |= bg_writel(cdev, rval->tshut_threshold,
> + tsr->tshut_threshold, &tsr->bg_reg_lock);
> /* Force immediate temperature measurement and update
> * of the DTEMP field
> */
> omap_bandgap_force_single_read(bg_ptr, i);
> - err |= omap_control_writel(cdev, rval->bg_counter,
> - tsr->bgap_counter);
> - err |= omap_control_writel(cdev, rval->bg_mode_ctrl,
> - tsr->bgap_mode_ctrl);
> - err |= omap_control_writel(cdev, rval->bg_ctrl,
> - tsr->bgap_mask_ctrl);
> + err |= bg_writel(cdev, rval->bg_counter,
> + tsr->bgap_counter, &tsr->bg_reg_lock);
> + err |= bg_writel(cdev, rval->bg_mode_ctrl,
> + tsr->bgap_mode_ctrl, &tsr->bg_reg_lock);
> + err |= bg_writel(cdev, rval->bg_ctrl,
> + tsr->bgap_mask_ctrl, &tsr->bg_reg_lock);
> } else {
> err |= omap_control_readl(cdev, tsr->temp_sensor_ctrl,
> &temp);
> @@ -1543,8 +1558,8 @@ static int omap_bandgap_restore_ctxt(str
> tsr->bgap_mask_ctrl,
> &temp);
> temp |= 1 << __ffs(tsr->mode_ctrl_mask);
> - err |= omap_control_writel(cdev, temp,
> - tsr->bgap_mask_ctrl);
> + err |= bg_writel(cdev, temp,
> + tsr->bgap_mask_ctrl, &tsr->bg_reg_lock);
> }
> }
> if (err)
> Index: omap-thermal/drivers/usb/otg/omap4-usb-phy.c
> ===================================================================
> --- omap-thermal.orig/drivers/usb/otg/omap4-usb-phy.c
> +++ omap-thermal/drivers/usb/otg/omap4-usb-phy.c
> @@ -46,13 +46,13 @@ int omap4_usb_phy_power(struct device *d
> if (on) {
> ret = omap_control_readl(dev, CONTROL_DEV_CONF, &val);
> if (!ret && (val & PHY_PD)) {
> - ret = omap_control_writel(dev, ~PHY_PD,
> + ret = omap_control_lock_writel(dev, ~PHY_PD,
> CONTROL_DEV_CONF);
> /* XXX: add proper documentation for this delay */
> mdelay(200);
> }
> } else {
> - ret = omap_control_writel(dev, PHY_PD, CONTROL_DEV_CONF);
> + ret = omap_control_lock_writel(dev, PHY_PD, CONTROL_DEV_CONF);
> }
>
> return ret;
> @@ -74,7 +74,7 @@ EXPORT_SYMBOL_GPL(omap4_usb_phy_power);
> */
> int omap4_usb_phy_mailbox(struct device *dev, u32 val)
> {
> - return omap_control_writel(dev, val, CONTROL_USBOTGHS_CONTROL);
> + return omap_control_lock_writel(dev, val, CONTROL_USBOTGHS_CONTROL);
> }
> EXPORT_SYMBOL_GPL(omap4_usb_phy_mailbox);
>
> Index: omap-thermal/include/linux/mfd/omap_control.h
> ===================================================================
> --- omap-thermal.orig/include/linux/mfd/omap_control.h
> +++ omap-thermal/include/linux/mfd/omap_control.h
> @@ -43,6 +43,7 @@ struct omap_control {
> #ifdef CONFIG_MFD_OMAP_CONTROL
> extern int omap_control_readl(struct device *dev, u32 reg, u32 *val);
> extern int omap_control_writel(struct device *dev, u32 val, u32 reg);
> +extern int omap_control_lock_writel(struct device *dev, u32 val, u32 reg);
> extern struct device *omap_control_get(void);
> extern void omap_control_put(struct device *dev);
> #else
> @@ -55,6 +56,11 @@ static inline int omap_control_writel(st
> {
> return 0;
> }
> +
> +static inline int omap_control_lock_writel(struct device *dev, u32 val, u32 reg)
> +{
> + return 0;
> +}
>
> static inline struct device *omap_control_get(void)
> {
>
>
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