Input: pxa27x_keypad - introduce driver structure and use KEY() to define matrix keys

 1. Introduce the "struct pxa27x_keypad" structure for driver specific
    information, such as "struct clk", generated matrix key codes and
    so on

 2. Use KEY() macro to define matrix keys, instead of original 8x8 map
    this makes definition easier with keypad where keys are sparse

 3. Keep a generated array in "struct pxa27x_keypad" for fast lookup

 4. Separate the matrix scan into a dedicated function for readability
    and report only those keys whose state has been changed, instead
    of report all states

 5. Make use of KPAS to decide the faster path if only one key has been
    detected

Signed-off-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

2 files changed, 184 insertions, 61 deletions

diff --git a/drivers/input/keyboard/pxa27x_keypad.c b/drivers/input/keyboard/pxa27x_keypad.c
index 43fb63d68122..8de35b0500f3 100644
--- a/drivers/input/keyboard/pxa27x_keypad.c
+++ b/drivers/input/keyboard/pxa27x_keypad.c
@@ -37,20 +37,120 @@
 
 #define DRIVER_NAME             "pxa27x-keypad"
 
-#define KPASMKP(col)            (col/2 == 0 ? KPASMKP0 : \
-                                 col/2 == 1 ? KPASMKP1 : \
-                                 col/2 == 2 ? KPASMKP2 : KPASMKP3)
-#define KPASMKPx_MKC(row, col)  (1 << (row + 16 * (col % 2)))
+#define KPAS_MUKP(n)            (((n) >> 26) & 0x1f)
+#define KPAS_RP(n)              (((n) >> 4) & 0xf)
+#define KPAS_CP(n)              ((n) & 0xf)
 
-static struct clk *pxa27x_keypad_clk;
+#define KPASMKP_MKC_MASK        (0xff)
+
+#define MAX_MATRIX_KEY_NUM      (8 * 8)
+
+struct pxa27x_keypad {
+        struct pxa27x_keypad_platform_data *pdata;
+
+        struct clk *clk;
+        struct input_dev *input_dev;
+
+        /* matrix key code map */
+        unsigned int matrix_keycodes[MAX_MATRIX_KEY_NUM];
+
+        /* state row bits of each column scan */
+        uint32_t matrix_key_state[MAX_MATRIX_KEY_COLS];
+};
+
+static void pxa27x_keypad_build_keycode(struct pxa27x_keypad *keypad)
+{
+        struct pxa27x_keypad_platform_data *pdata = keypad->pdata;
+        struct input_dev *input_dev = keypad->input_dev;
+        unsigned int *key;
+        int i;
+
+        key = &pdata->matrix_key_map[0];
+        for (i = 0; i < pdata->matrix_key_map_size; i++, key++) {
+                int row = ((*key) >> 28) & 0xf;
+                int col = ((*key) >> 24) & 0xf;
+                int code = (*key) & 0xffffff;
+
+                keypad->matrix_keycodes[(row << 3) + col] = code;
+                set_bit(code, input_dev->keybit);
+        }
+}
+
+static inline unsigned int lookup_matrix_keycode(
+                struct pxa27x_keypad *keypad, int row, int col)
+{
+        return keypad->matrix_keycodes[(row << 3) + col];
+}
+
+static void pxa27x_keypad_scan_matrix(struct pxa27x_keypad *keypad)
+{
+        struct pxa27x_keypad_platform_data *pdata = keypad->pdata;
+        int row, col, num_keys_pressed = 0;
+        uint32_t new_state[MAX_MATRIX_KEY_COLS];
+        uint32_t kpas = KPAS;
+
+        num_keys_pressed = KPAS_MUKP(kpas);
+
+        memset(new_state, 0, sizeof(new_state));
+
+        if (num_keys_pressed == 0)
+                goto scan;
+
+        if (num_keys_pressed == 1) {
+                col = KPAS_CP(kpas);
+                row = KPAS_RP(kpas);
+
+                /* if invalid row/col, treat as no key pressed */
+                if (col >= pdata->matrix_key_cols ||
+                    row >= pdata->matrix_key_rows)
+                        goto scan;
+
+                new_state[col] = (1 << row);
+                goto scan;
+        }
+
+        if (num_keys_pressed > 1) {
+                uint32_t kpasmkp0 = KPASMKP0;
+                uint32_t kpasmkp1 = KPASMKP1;
+                uint32_t kpasmkp2 = KPASMKP2;
+                uint32_t kpasmkp3 = KPASMKP3;
+
+                new_state[0] = kpasmkp0 & KPASMKP_MKC_MASK;
+                new_state[1] = (kpasmkp0 >> 16) & KPASMKP_MKC_MASK;
+                new_state[2] = kpasmkp1 & KPASMKP_MKC_MASK;
+                new_state[3] = (kpasmkp1 >> 16) & KPASMKP_MKC_MASK;
+                new_state[4] = kpasmkp2 & KPASMKP_MKC_MASK;
+                new_state[5] = (kpasmkp2 >> 16) & KPASMKP_MKC_MASK;
+                new_state[6] = kpasmkp3 & KPASMKP_MKC_MASK;
+                new_state[7] = (kpasmkp3 >> 16) & KPASMKP_MKC_MASK;
+        }
+scan:
+        for (col = 0; col < pdata->matrix_key_cols; col++) {
+                uint32_t bits_changed;
+
+                bits_changed = keypad->matrix_key_state[col] ^ new_state[col];
+                if (bits_changed == 0)
+                        continue;
+
+                for (row = 0; row < pdata->matrix_key_rows; row++) {
+                        if ((bits_changed & (1 << row)) == 0)
+                                continue;
+
+                        input_report_key(keypad->input_dev,
+                                lookup_matrix_keycode(keypad, row, col),
+                                new_state[col] & (1 << row));
+                }
+        }
+        input_sync(keypad->input_dev);
+        memcpy(keypad->matrix_key_state, new_state, sizeof(new_state));
+}
 
 static irqreturn_t pxa27x_keypad_irq_handler(int irq, void *dev_id)
 {
-        struct platform_device *pdev = dev_id;
-        struct pxa27x_keypad_platform_data *pdata = pdev->dev.platform_data;
-        struct input_dev *input_dev = platform_get_drvdata(pdev);
+        struct pxa27x_keypad *keypad = dev_id;
+        struct input_dev *input_dev = keypad->input_dev;
         unsigned long kpc = KPC;
-        int p, row, col, rel;
+        int rel;
 
         if (kpc & KPC_DI) {
                 unsigned long kpdk = KPDK;
@@ -75,26 +175,16 @@ static irqreturn_t pxa27x_keypad_irq_handler(int irq, void *dev_id)
                 }
         }
 
-        if (kpc & KPC_MI) {
-                /* report the status of every button */
-                for (row = 0; row < pdata->nr_rows; row++) {
-                        for (col = 0; col < pdata->nr_cols; col++) {
-                                p = KPASMKP(col) & KPASMKPx_MKC(row, col) ?
-                                        1 : 0;
-                                pr_debug("keycode %x - pressed %x\n",
-                                                pdata->keycodes[row][col], p);
-                                input_report_key(input_dev,
-                                                pdata->keycodes[row][col], p);
-                        }
-                }
-                input_sync(input_dev);
-        }
+        if (kpc & KPC_MI)
+                pxa27x_keypad_scan_matrix(keypad);
 
         return IRQ_HANDLED;
 }
 
 static int pxa27x_keypad_open(struct input_dev *dev)
 {
+        struct pxa27x_keypad *keypad = input_get_drvdata(dev);
+
         /* Set keypad control register */
         KPC |= (KPC_ASACT |
                 KPC_MS_ALL |
@@ -108,21 +198,24 @@ static int pxa27x_keypad_open(struct input_dev *dev)
         KPREC = 0x7F;
 
         /* Enable unit clock */
-        clk_enable(pxa27x_keypad_clk);
+        clk_enable(keypad->clk);
 
         return 0;
 }
 
 static void pxa27x_keypad_close(struct input_dev *dev)
 {
+        struct pxa27x_keypad *keypad = input_get_drvdata(dev);
+
         /* Disable clock unit */
-        clk_disable(pxa27x_keypad_clk);
+        clk_disable(keypad->clk);
 }
 
 #ifdef CONFIG_PM
 static int pxa27x_keypad_suspend(struct platform_device *pdev, pm_message_t state)
 {
-        struct pxa27x_keypad_platform_data *pdata = pdev->dev.platform_data;
+        struct pxa27x_keypad *keypad = platform_get_drvdata(pdev);
+        struct pxa27x_keypad_platform_data *pdata = keypad->pdata;
 
         /* Save controller status */
         pdata->reg_kpc = KPC;
@@ -133,8 +226,9 @@ static int pxa27x_keypad_suspend(struct platform_device *pdev, pm_message_t stat
 
 static int pxa27x_keypad_resume(struct platform_device *pdev)
 {
-        struct pxa27x_keypad_platform_data *pdata = pdev->dev.platform_data;
-        struct input_dev *input_dev = platform_get_drvdata(pdev);
+        struct pxa27x_keypad *keypad = platform_get_drvdata(pdev);
+        struct pxa27x_keypad_platform_data *pdata = keypad->pdata;
+        struct input_dev *input_dev = keypad->input_dev;
 
         mutex_lock(&input_dev->mutex);
 
@@ -144,8 +238,7 @@ static int pxa27x_keypad_resume(struct platform_device *pdev)
                 KPREC = pdata->reg_kprec;
 
                 /* Enable unit clock */
-                clk_disable(pxa27x_keypad_clk);
-                clk_enable(pxa27x_keypad_clk);
+                clk_enable(keypad->clk);
         }
 
         mutex_unlock(&input_dev->mutex);
@@ -159,22 +252,36 @@ static int pxa27x_keypad_resume(struct platform_device *pdev)
 
 static int __devinit pxa27x_keypad_probe(struct platform_device *pdev)
 {
-        struct pxa27x_keypad_platform_data *pdata = pdev->dev.platform_data;
+        struct pxa27x_keypad *keypad;
         struct input_dev *input_dev;
-        int i, row, col, error;
+        int col, error;
 
-        pxa27x_keypad_clk = clk_get(&pdev->dev, "KBDCLK");
-        if (IS_ERR(pxa27x_keypad_clk)) {
-                error = PTR_ERR(pxa27x_keypad_clk);
-                goto err_clk;
+        keypad = kzalloc(sizeof(struct pxa27x_keypad), GFP_KERNEL);
+        if (keypad == NULL) {
+                dev_err(&pdev->dev, "failed to allocate driver data\n");
+                return -ENOMEM;
+        }
+
+        keypad->pdata = pdev->dev.platform_data;
+        if (keypad->pdata == NULL) {
+                dev_err(&pdev->dev, "no platform data defined\n");
+                error = -EINVAL;
+                goto failed_free;
+        }
+
+        keypad->clk = clk_get(&pdev->dev, "KBDCLK");
+        if (IS_ERR(keypad->clk)) {
+                dev_err(&pdev->dev, "failed to get keypad clock\n");
+                error = PTR_ERR(keypad->clk);
+                goto failed_free;
         }
 
         /* Create and register the input driver. */
         input_dev = input_allocate_device();
         if (!input_dev) {
-                printk(KERN_ERR "Cannot request keypad device\n");
+                dev_err(&pdev->dev, "failed to allocate input device\n");
                 error = -ENOMEM;
-                goto err_alloc;
+                goto failed_put_clk;
         }
 
         input_dev->name = DRIVER_NAME;
@@ -183,25 +290,23 @@ static int __devinit pxa27x_keypad_probe(struct platform_device *pdev)
         input_dev->close = pxa27x_keypad_close;
         input_dev->dev.parent = &pdev->dev;
 
+        keypad->input_dev = input_dev;
+        input_set_drvdata(input_dev, keypad);
+
         input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP) |
                 BIT_MASK(EV_REL);
         input_dev->relbit[BIT_WORD(REL_WHEEL)] = BIT_MASK(REL_WHEEL);
-        for (row = 0; row < pdata->nr_rows; row++) {
-                for (col = 0; col < pdata->nr_cols; col++) {
-                        int code = pdata->keycodes[row][col];
-                        if (code > 0)
-                                set_bit(code, input_dev->keybit);
-                }
-        }
+
+        pxa27x_keypad_build_keycode(keypad);
 
         error = request_irq(IRQ_KEYPAD, pxa27x_keypad_irq_handler, IRQF_DISABLED,
-                            DRIVER_NAME, pdev);
+                            DRIVER_NAME, keypad);
         if (error) {
                 printk(KERN_ERR "Cannot request keypad IRQ\n");
                 goto err_free_dev;
         }
 
-        platform_set_drvdata(pdev, input_dev);
+        platform_set_drvdata(pdev, keypad);
 
         /* Register the input device */
         error = input_register_device(input_dev);
@@ -212,10 +317,10 @@ static int __devinit pxa27x_keypad_probe(struct platform_device *pdev)
          * Store rows/cols info into keyboard registers.
          */
 
-        KPC |= (pdata->nr_rows - 1) << 26;
-        KPC |= (pdata->nr_cols - 1) << 23;
+        KPC |= (keypad->pdata->matrix_key_rows - 1) << 26;
+        KPC |= (keypad->pdata->matrix_key_cols - 1) << 23;
 
-        for (col = 0; col < pdata->nr_cols; col++)
+        for (col = 0; col < keypad->pdata->matrix_key_cols; col++)
                 KPC |= KPC_MS0 << col;
 
         return 0;
@@ -225,21 +330,26 @@ static int __devinit pxa27x_keypad_probe(struct platform_device *pdev)
         free_irq(IRQ_KEYPAD, pdev);
  err_free_dev:
         input_free_device(input_dev);
- err_alloc:
-        clk_put(pxa27x_keypad_clk);
- err_clk:
+failed_put_clk:
+        clk_put(keypad->clk);
+failed_free:
+        kfree(keypad);
         return error;
 }
 
 static int __devexit pxa27x_keypad_remove(struct platform_device *pdev)
 {
-        struct input_dev *input_dev = platform_get_drvdata(pdev);
+        struct pxa27x_keypad *keypad = platform_get_drvdata(pdev);
 
-        input_unregister_device(input_dev);
         free_irq(IRQ_KEYPAD, pdev);
-        clk_put(pxa27x_keypad_clk);
-        platform_set_drvdata(pdev, NULL);
 
+        clk_disable(keypad->clk);
+        clk_put(keypad->clk);
+
+        input_unregister_device(keypad->input_dev);
+
+        platform_set_drvdata(pdev, NULL);
+        kfree(keypad);
         return 0;
 }
 
diff --git a/include/asm-arm/arch-pxa/pxa27x_keypad.h b/include/asm-arm/arch-pxa/pxa27x_keypad.h
index ef17db6d791e..1b1bf9fe6d81 100644
--- a/include/asm-arm/arch-pxa/pxa27x_keypad.h
+++ b/include/asm-arm/arch-pxa/pxa27x_keypad.h
@@ -1,12 +1,25 @@
-#define PXAKBD_MAXROW           8
-#define PXAKBD_MAXCOL           8
+#ifndef __ASM_ARCH_PXA27x_KEYPAD_H
+#define __ASM_ARCH_PXA27x_KEYPAD_H
+
+#include <linux/input.h>
+
+#define MAX_MATRIX_KEY_ROWS     (8)
+#define MAX_MATRIX_KEY_COLS     (8)
 
 struct pxa27x_keypad_platform_data {
-        int nr_rows, nr_cols;
-        int keycodes[PXAKBD_MAXROW][PXAKBD_MAXCOL];
+
+        /* code map for the matrix keys */
+        unsigned int    matrix_key_rows;
+        unsigned int    matrix_key_cols;
+        unsigned int    *matrix_key_map;
+        int             matrix_key_map_size;
 
 #ifdef CONFIG_PM
         u32 reg_kpc;
         u32 reg_kprec;
 #endif
 };
+
+#define KEY(row, col, val)      (((row) << 28) | ((col) << 24) | (val))
+
+#endif /* __ASM_ARCH_PXA27x_KEYPAD_H */