Re: [PATCH 3/12] pxa: introduce driver structure and use KEY() to define matrix keys

["eric miao" <eric.y.miao@gmail.com>]

On Jan 29, 2008 2:33 PM, Dmitry Torokhov <dtor@insightbb.com> wrote:
> Hi Eric,
>
> On Wednesday 23 January 2008 02:24, eric miao wrote:
> > From 606a2f30cd7086c5f193b3d92e9f7f06c0b62603 Mon Sep 17 00:00:00 2001
> > From: eric miao <eric.miao@marvell.com>
> > Date: Tue, 22 Jan 2008 18:09:10 +0800
> > Subject: [PATCH] pxa: 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
> >
>
> I am a bit concerned with loss of backward compatibility with the driver.
> While there are currently no users of it inside the mainline kernel there
> may be people using it in the wild. Let's ask Rodolfo if he can cope
> with this change...
>
> Alternative woudl be do something like:
>
> #define KEY(row, col, code)  [((row) << 3) + (col)] = (code)
>
> which would allow defining starse keymaps.
>

This is also excellent idea, indeed. The only concern is that someone
argues that platform_data should be discarded (marked as __initdata)
once the driver is up and running. Although I hold preservative opinion
about this.

>
>
> > 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>
> > ---
> >  drivers/input/keyboard/pxa27x_keypad.c   |  224 ++++++++++++++++++++++--------
> >  include/asm-arm/arch-pxa/pxa27x_keypad.h |   21 +++-
> >  2 files changed, 184 insertions(+), 61 deletions(-)
> >
> > diff --git a/drivers/input/keyboard/pxa27x_keypad.c
> > b/drivers/input/keyboard/pxa27x_keypad.c
> > index 43fb63d..8de35b0 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 ef17db6..1b1bf9f 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 */
> > --
> > 1.5.2.5.GIT
> >
> >
> >
>
> --
> Dmitry
>



-- 
Cheers
- eric