Input: imx6ul_tsc - generalize the averaging property

[linux-2.6-block.git] / drivers / input / touchscreen / imx6ul_tsc.c

diff --git a/drivers/input/touchscreen/imx6ul_tsc.c b/drivers/input/touchscreen/imx6ul_tsc.c
index 8275267eac25441f308e6103e82d48830d1feb71..7098e0a47019539b7cc3482fe3043576a123e348 100644 (file)
--- a/drivers/input/touchscreen/imx6ul_tsc.c
+++ b/drivers/input/touchscreen/imx6ul_tsc.c
@@ -21,17 +21,25 @@
 #include <linux/platform_device.h>
 #include <linux/clk.h>
 #include <linux/io.h>
+#include <linux/log2.h>
 
 /* ADC configuration registers field define */
 #define ADC_AIEN               (0x1 << 7)
 #define ADC_CONV_DISABLE       0x1F
+#define ADC_AVGE               (0x1 << 5)
 #define ADC_CAL                        (0x1 << 7)
 #define ADC_CALF               0x2
 #define ADC_12BIT_MODE         (0x2 << 2)
+#define ADC_CONV_MODE_MASK     (0x3 << 2)
 #define ADC_IPG_CLK            0x00
+#define ADC_INPUT_CLK_MASK     0x3
 #define ADC_CLK_DIV_8          (0x03 << 5)
+#define ADC_CLK_DIV_MASK       (0x3 << 5)
 #define ADC_SHORT_SAMPLE_MODE  (0x0 << 4)
+#define ADC_SAMPLE_MODE_MASK   (0x1 << 4)
 #define ADC_HARDWARE_TRIGGER   (0x1 << 13)
+#define ADC_AVGS_SHIFT         14
+#define ADC_AVGS_MASK          (0x3 << 14)
 #define SELECT_CHANNEL_4       0x04
 #define SELECT_CHANNEL_1       0x01
 #define DISABLE_CONVERSION_INT (0x0 << 7)
@@ -84,8 +92,10 @@ struct imx6ul_tsc {
        struct clk *adc_clk;
        struct gpio_desc *xnur_gpio;
 
-       int measure_delay_time;
-       int pre_charge_time;
+       u32 measure_delay_time;
+       u32 pre_charge_time;
+       bool average_enable;
+       u32 average_select;
 
        struct completion completion;
 };
@@ -96,17 +106,23 @@ struct imx6ul_tsc {
  */
 static int imx6ul_adc_init(struct imx6ul_tsc *tsc)
 {
-       int adc_hc = 0;
-       int adc_gc;
-       int adc_gs;
-       int adc_cfg;
-       int timeout;
+       u32 adc_hc = 0;
+       u32 adc_gc;
+       u32 adc_gs;
+       u32 adc_cfg;
+       unsigned long timeout;
 
        reinit_completion(&tsc->completion);
 
        adc_cfg = readl(tsc->adc_regs + REG_ADC_CFG);
+       adc_cfg &= ~(ADC_CONV_MODE_MASK | ADC_INPUT_CLK_MASK);
        adc_cfg |= ADC_12BIT_MODE | ADC_IPG_CLK;
+       adc_cfg &= ~(ADC_CLK_DIV_MASK | ADC_SAMPLE_MODE_MASK);
        adc_cfg |= ADC_CLK_DIV_8 | ADC_SHORT_SAMPLE_MODE;
+       if (tsc->average_enable) {
+               adc_cfg &= ~ADC_AVGS_MASK;
+               adc_cfg |= (tsc->average_select) << ADC_AVGS_SHIFT;
+       }
        adc_cfg &= ~ADC_HARDWARE_TRIGGER;
        writel(adc_cfg, tsc->adc_regs + REG_ADC_CFG);
 
@@ -118,6 +134,8 @@ static int imx6ul_adc_init(struct imx6ul_tsc *tsc)
        /* start ADC calibration */
        adc_gc = readl(tsc->adc_regs + REG_ADC_GC);
        adc_gc |= ADC_CAL;
+       if (tsc->average_enable)
+               adc_gc |= ADC_AVGE;
        writel(adc_gc, tsc->adc_regs + REG_ADC_GC);
 
        timeout = wait_for_completion_timeout
@@ -148,7 +166,7 @@ static int imx6ul_adc_init(struct imx6ul_tsc *tsc)
  */
 static void imx6ul_tsc_channel_config(struct imx6ul_tsc *tsc)
 {
-       int adc_hc0, adc_hc1, adc_hc2, adc_hc3, adc_hc4;
+       u32 adc_hc0, adc_hc1, adc_hc2, adc_hc3, adc_hc4;
 
        adc_hc0 = DISABLE_CONVERSION_INT;
        writel(adc_hc0, tsc->adc_regs + REG_ADC_HC0);
@@ -173,8 +191,8 @@ static void imx6ul_tsc_channel_config(struct imx6ul_tsc *tsc)
  */
 static void imx6ul_tsc_set(struct imx6ul_tsc *tsc)
 {
-       int basic_setting = 0;
-       int start;
+       u32 basic_setting = 0;
+       u32 start;
 
        basic_setting |= tsc->measure_delay_time << 8;
        basic_setting |= DETECT_4_WIRE_MODE | AUTO_MEASURE;
@@ -209,8 +227,8 @@ static int imx6ul_tsc_init(struct imx6ul_tsc *tsc)
 
 static void imx6ul_tsc_disable(struct imx6ul_tsc *tsc)
 {
-       int tsc_flow;
-       int adc_cfg;
+       u32 tsc_flow;
+       u32 adc_cfg;
 
        /* TSC controller enters to idle status */
        tsc_flow = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
@@ -227,8 +245,8 @@ static void imx6ul_tsc_disable(struct imx6ul_tsc *tsc)
 static bool tsc_wait_detect_mode(struct imx6ul_tsc *tsc)
 {
        unsigned long timeout = jiffies + msecs_to_jiffies(2);
-       int state_machine;
-       int debug_mode2;
+       u32 state_machine;
+       u32 debug_mode2;
 
        do {
                if (time_after(jiffies, timeout))
@@ -246,10 +264,10 @@ static bool tsc_wait_detect_mode(struct imx6ul_tsc *tsc)
 static irqreturn_t tsc_irq_fn(int irq, void *dev_id)
 {
        struct imx6ul_tsc *tsc = dev_id;
-       int status;
-       int value;
-       int x, y;
-       int start;
+       u32 status;
+       u32 value;
+       u32 x, y;
+       u32 start;
 
        status = readl(tsc->tsc_regs + REG_TSC_INT_STATUS);
 
@@ -289,8 +307,8 @@ static irqreturn_t tsc_irq_fn(int irq, void *dev_id)
 static irqreturn_t adc_irq_fn(int irq, void *dev_id)
 {
        struct imx6ul_tsc *tsc = dev_id;
-       int coco;
-       int value;
+       u32 coco;
+       u32 value;
 
        coco = readl(tsc->adc_regs + REG_ADC_HS);
        if (coco & 0x01) {
@@ -346,6 +364,7 @@ static int imx6ul_tsc_probe(struct platform_device *pdev)
        int err;
        int tsc_irq;
        int adc_irq;
+       u32 average_samples;
 
        tsc = devm_kzalloc(&pdev->dev, sizeof(*tsc), GFP_KERNEL);
        if (!tsc)
@@ -450,6 +469,30 @@ static int imx6ul_tsc_probe(struct platform_device *pdev)
        if (err)
                tsc->pre_charge_time = 0xfff;
 
+       err = of_property_read_u32(np, "touchscreen-average-samples",
+                                  &average_samples);
+       if (err)
+               average_samples = 1;
+
+       switch (average_samples) {
+       case 1:
+               tsc->average_enable = false;
+               tsc->average_select = 0; /* value unused; initialize anyway */
+               break;
+       case 4:
+       case 8:
+       case 16:
+       case 32:
+               tsc->average_enable = true;
+               tsc->average_select = ilog2(average_samples) - 2;
+               break;
+       default:
+               dev_err(&pdev->dev,
+                       "touchscreen-average-samples (%u) must be 1, 4, 8, 16 or 32\n",
+                       average_samples);
+               return -EINVAL;
+       }
+
        err = input_register_device(tsc->input);
        if (err) {
                dev_err(&pdev->dev,