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SubjectRe: [PATCH 2/2] Input: bcm-keypad: Add Broadcom keypad controller
Hi Dmitry,

Good review. Thanks. Commented inline.

On 15-02-09 05:02 PM, Dmitry Torokhov wrote:
> Hi Scott,
>
> On Mon, Feb 09, 2015 at 04:07:41PM -0800, Scott Branden wrote:
>> Add driver for Broadcom's keypad controller.
>>
>> Broadcom Keypad controller is used to interface a SoC with a matrix-type
>> keypad device. The keypad controller supports multiple row and column lines.
>> A key can be placed at each intersection of a unique row and a unique column.
>> The keypad controller can sense a key-press and key-release and report the
>> event using a interrupt to the cpu.
>>
>> Reviewed-by: Ray Jui <rjui@broadcom.com>
>> Signed-off-by: Scott Branden <sbranden@broadcom.com>
>> ---
>> drivers/input/keyboard/Kconfig | 10 +
>> drivers/input/keyboard/Makefile | 1 +
>> drivers/input/keyboard/bcm-keypad.c | 489 ++++++++++++++++++++++++++++++++++++
>> 3 files changed, 500 insertions(+)
>> create mode 100644 drivers/input/keyboard/bcm-keypad.c
>>
>> diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
>> index a5d9b3f..3a0c0f2 100644
>> --- a/drivers/input/keyboard/Kconfig
>> +++ b/drivers/input/keyboard/Kconfig
>> @@ -676,4 +676,14 @@ config KEYBOARD_CAP11XX
>> To compile this driver as a module, choose M here: the
>> module will be called cap11xx.
>>
>> +config KEYBOARD_BCM
>> + tristate "Broadcom keypad driver"
>> + select INPUT_MATRIXKMAP
>> + default ARCH_BCM_CYGNUS
>> + help
>> + Say Y here if you want to use Broadcom keypad.
>> +
>> + To compile this driver as a module, choose M here: the
>> + module will be called bcm-keypad.
>> +
>> endif
>> diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
>> index febafa5..3cff8f6 100644
>> --- a/drivers/input/keyboard/Makefile
>> +++ b/drivers/input/keyboard/Makefile
>> @@ -10,6 +10,7 @@ obj-$(CONFIG_KEYBOARD_ADP5589) += adp5589-keys.o
>> obj-$(CONFIG_KEYBOARD_AMIGA) += amikbd.o
>> obj-$(CONFIG_KEYBOARD_ATARI) += atakbd.o
>> obj-$(CONFIG_KEYBOARD_ATKBD) += atkbd.o
>> +obj-$(CONFIG_KEYBOARD_BCM) += bcm-keypad.o
>> obj-$(CONFIG_KEYBOARD_BFIN) += bf54x-keys.o
>> obj-$(CONFIG_KEYBOARD_CAP11XX) += cap11xx.o
>> obj-$(CONFIG_KEYBOARD_CLPS711X) += clps711x-keypad.o
>> diff --git a/drivers/input/keyboard/bcm-keypad.c b/drivers/input/keyboard/bcm-keypad.c
>> new file mode 100644
>> index 0000000..b2c4bb7
>> --- /dev/null
>> +++ b/drivers/input/keyboard/bcm-keypad.c
>> @@ -0,0 +1,489 @@
>> +/*
>> + * Copyright (C) 2014 Broadcom Corporation
>> + *
>> + * This program is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU General Public License as
>> + * published by the Free Software Foundation version 2.
>> + *
>> + * This program is distributed "as is" WITHOUT ANY WARRANTY of any
>> + * kind, whether express or implied; without even the implied warranty
>> + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>> + * GNU General Public License for more details.
>> + */
>> +
>> +#include <linux/mm.h>
>> +#include <linux/module.h>
>> +#include <linux/input.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/bitops.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/delay.h>
>> +#include <linux/sizes.h>
>> +#include <linux/stddef.h>
>> +#include <linux/of.h>
>> +#include <linux/of_irq.h>
>> +#include <linux/slab.h>
>> +#include <linux/clk.h>
>> +#include <linux/types.h>
>> +#include <linux/string.h>
>> +#include <asm/memory.h>
>> +#include <linux/io.h>
>> +#include <linux/input/matrix_keypad.h>
>> +
>> +#define DEFAULT_CLK_HZ 31250
>> +/* Repeat period (ms) */
>> +#define KEY_REPEAT_PERIOD 100
>> +/* First time press dly (ms) */
>> +#define KEY_REPEAT_DELAY 400
>> +#define MAX_ROWS 8
>> +#define MAX_COLS 8
>> +
>> +/* Register/field definitions */
>> +#define KPCR_OFFSET 0x00000080
>> +#define KPCR_MODE 0x00000002
>> +#define KPCR_MODE_SHIFT 1
>> +#define KPCR_MODE_MASK 1
>> +#define KPCR_ENABLE 0x00000001
>> +#define KPCR_STATUSFILTERENABLE 0x00008000
>> +#define KPCR_STATUSFILTERTYPE_SHIFT 12
>> +#define KPCR_COLFILTERENABLE 0x00000800
>> +#define KPCR_COLFILTERTYPE_SHIFT 8
>> +#define KPCR_ROWWIDTH_SHIFT 20
>> +#define KPCR_COLUMNWIDTH_SHIFT 16
>> +
>> +#define KPIOR_OFFSET 0x00000084
>> +#define KPIOR_ROWOCONTRL_SHIFT 24
>> +#define KPIOR_ROWOCONTRL_MASK 0xFF000000
>> +#define KPIOR_COLUMNOCONTRL_SHIFT 16
>> +#define KPIOR_COLUMNOCONTRL_MASK 0x00FF0000
>> +#define KPIOR_COLUMN_IO_DATA_SHIFT 0
>> +
>> +#define KPEMR0_OFFSET 0x00000090
>> +#define KPEMR1_OFFSET 0x00000094
>> +#define KPEMR2_OFFSET 0x00000098
>> +#define KPEMR3_OFFSET 0x0000009C
>> +#define KPEMR_EDGETYPE_MAX 3
>> +
>> +#define KPSSR0_OFFSET 0x000000A0
>> +#define KPSSR1_OFFSET 0x000000A4
>> +#define KPIMR0_OFFSET 0x000000B0
>> +#define KPIMR1_OFFSET 0x000000B4
>> +#define KPICR0_OFFSET 0x000000B8
>> +#define KPICR1_OFFSET 0x000000BC
>> +#define KPISR0_OFFSET 0x000000C0
>> +#define KPISR1_OFFSET 0x000000C4
>> +
>> +#define KPCR_STATUSFILTERTYPE_MAX 7
>> +#define KPCR_COLFILTERTYPE_MAX 7
>> +
>> +/* Macros to determine the row/column from a bit that is set in SSR0/1. */
>> +#define BIT_TO_ROW_SSR0(bit_nr) (bit_nr >> 3)
>> +#define BIT_TO_ROW_SSR1(bit_nr) ((bit_nr >> 3) + 4)
>> +#define BIT_TO_COL(bit_nr) (bit_nr % 8)
>> +
>> +/* Structure representing various run-time entities */
>> +struct bcm_kp {
>> + void __iomem *base;
>> + int irq;
>> + struct clk *clk;
>> + struct input_dev *input_dev;
>> + unsigned long last_state[2];
>> + unsigned int n_rows;
>> + unsigned int n_cols;
>> + u32 kpcr;
>> + u32 kpior;
>> + u32 kpemr;
>> + u32 imr0_val;
>> + u32 imr1_val;
>> +};
>> +
>> +/*
>> + * Returns the keycode from the input device keymap given the row and
>> + * column.
>> + */
>> +static inline int bcm_kp_get_keycode(struct bcm_kp *kp, int row, int col)
>> +{
>> + unsigned int row_shift = get_count_order(kp->n_cols);
>> + unsigned short *keymap = kp->input_dev->keycode;
>> +
>> + return keymap[MATRIX_SCAN_CODE(row, col, row_shift)];
>> +}
>> +
>> +static irqreturn_t bcm_kp_isr_thread(int irq, void *dev_id)
>> +{
>> + struct bcm_kp *kp = dev_id;
>> + unsigned long state, change;
>> + int bit_nr;
>> + int pull_mode = (kp->kpcr >> KPCR_MODE_SHIFT) & KPCR_MODE_MASK;
>> + int key_press;
>> + int row, col;
>> + unsigned int keycode;
>> +
>> + /* Clear interrupts */
>> + writel(0xFFFFFFFF, kp->base + KPICR0_OFFSET);
>> + writel(0xFFFFFFFF, kp->base + KPICR1_OFFSET);
>> +
>> + state = readl(kp->base + KPSSR0_OFFSET);
>> + change = kp->last_state[0] ^ state;
>> + kp->last_state[0] = state;
>> +
>> + for_each_set_bit(bit_nr, &change, BITS_PER_LONG) {
>> + key_press = state & BIT(bit_nr);
>> + /* The meaning of SSR register depends on pull mode. */
>> + key_press = pull_mode ? !key_press : key_press;
>> + row = BIT_TO_ROW_SSR0(bit_nr);
>> + col = BIT_TO_COL(bit_nr);
>> + keycode = bcm_kp_get_keycode(kp, row, col);
>> + input_report_key(kp->input_dev, keycode, key_press);
>> + }
>> +
>> + state = readl(kp->base + KPSSR1_OFFSET);
>> + change = kp->last_state[1] ^ state;
>> + kp->last_state[1] = state;
>> +
>> + for_each_set_bit(bit_nr, &change, BITS_PER_LONG) {
>> + key_press = state & BIT(bit_nr);
>> + /* The meaning of SSR register depends on pull mode. */
>> + key_press = pull_mode ? !key_press : key_press;
>> + row = BIT_TO_ROW_SSR1(bit_nr);
>> + col = BIT_TO_COL(bit_nr);
>> + keycode = bcm_kp_get_keycode(kp, row, col);
>> + input_report_key(kp->input_dev, keycode, key_press);
>> + }
>
> Please split it into a separate function that processes one bank and
> call it twice instead of doing cut-and-paste of almost the same code. Or
> even better combine it all into one block (i.e have changes[2], use
> bitmap_xor to figure difference, etc...).
>
OK. It was a few lines of code called twice but I'll change it.

>> +
>> + input_sync(kp->input_dev);
>> +
>> + return IRQ_HANDLED;
>> +}
>> +
>> +static int bcm_kp_start(struct bcm_kp *kp)
>> +{
>> + int error;
>> +
>> + error = clk_prepare_enable(kp->clk);
>> + if (error)
>> + return error;
>> +
>> + writel(kp->kpior, kp->base + KPIOR_OFFSET);
>> +
>> + writel(kp->imr0_val, kp->base + KPIMR0_OFFSET);
>> + writel(kp->imr1_val, kp->base + KPIMR1_OFFSET);
>> +
>> + writel(kp->kpemr, kp->base + KPEMR0_OFFSET);
>> + writel(kp->kpemr, kp->base + KPEMR1_OFFSET);
>> + writel(kp->kpemr, kp->base + KPEMR2_OFFSET);
>> + writel(kp->kpemr, kp->base + KPEMR3_OFFSET);
>> +
>> + writel(0xFFFFFFFF, kp->base + KPICR0_OFFSET);
>> + writel(0xFFFFFFFF, kp->base + KPICR1_OFFSET);
>> +
>> + kp->last_state[0] = readl(kp->base + KPSSR0_OFFSET);
>> + kp->last_state[0] = readl(kp->base + KPSSR1_OFFSET);
>> +
>> + writel(kp->kpcr | KPCR_ENABLE, kp->base + KPCR_OFFSET);
>> +
>> + return 0;
>> +}
>> +
>> +static void bcm_kp_stop(const struct bcm_kp *kp)
>> +{
>> + u32 val;
>> +
>> + val = readl(kp->base + KPCR_OFFSET);
>> + val &= ~KPCR_ENABLE;
>> + writel(0, kp->base + KPCR_OFFSET);
>> + writel(0, kp->base + KPIMR0_OFFSET);
>> + writel(0, kp->base + KPIMR1_OFFSET);
>> + writel(0xFFFFFFFF, kp->base + KPICR0_OFFSET);
>> + writel(0xFFFFFFFF, kp->base + KPICR1_OFFSET);
>> +
>> + clk_disable_unprepare(kp->clk);
>> +}
>> +
>> +static int bcm_kp_open(struct input_dev *dev)
>> +{
>> + struct bcm_kp *kp = input_get_drvdata(dev);
>> +
>> + return bcm_kp_start(kp);
>> +}
>> +
>> +static void bcm_kp_close(struct input_dev *dev)
>> +{
>> + struct bcm_kp *kp = input_get_drvdata(dev);
>> +
>> + bcm_kp_stop(kp);
>> +}
>> +
>> +static int bcm_kp_matrix_key_parse_dt(struct bcm_kp *kp)
>> +{
>> + struct device *dev = kp->input_dev->dev.parent;
>> + struct device_node *np = dev->of_node;
>> + int error;
>> + unsigned int dt_val;
>> + unsigned int i;
>> +
>> + /* Initialize the KPCR Keypad Configuration Register */
>> + kp->kpcr = KPCR_STATUSFILTERENABLE | KPCR_COLFILTERENABLE;
>> +
>> + error = matrix_keypad_parse_of_params(dev, &kp->n_rows, &kp->n_cols);
>> + if (error) {
>> + dev_err(dev, "failed to parse kp params\n");
>> + return error;
>> + }
>> + /* Set row width for the ASIC block. */
>> + kp->kpcr |= (kp->n_rows - 1) << KPCR_ROWWIDTH_SHIFT;
>> +
>> + /* Set column width for the ASIC block. */
>> + kp->kpcr |= (kp->n_cols - 1) << KPCR_COLUMNWIDTH_SHIFT;
>> +
>> + /* Configure the IMR registers */
>> + {
>> + unsigned int num_rows, col_mask, rows_set;
>> +
>> + /* IMR registers contain interrupt enable bits for 8x8 matrix
>> + * IMR0 register format: <row3> <row2> <row1> <row0>
>> + * IMR1 register format: <row7> <row6> <row5> <row4>
>> + */
>> +
>> + col_mask = (1 << (kp->n_cols)) - 1;
>> + num_rows = kp->n_rows;
>> +
>> + /* Set column bits in rows 0 to 3 in IMR0 */
>> + kp->imr0_val = col_mask;
>> +
>> + rows_set = 1;
>> + while ((--num_rows) && (rows_set++ < 4))
>> + kp->imr0_val |= (kp->imr0_val << MAX_COLS);
>> +
>> + /* Set column bits in rows 4 to 7 in IMR1 */
>> + kp->imr1_val = 0;
>> + if (num_rows) {
>> + kp->imr1_val = col_mask;
>> + while (--num_rows)
>> + kp->imr1_val |= (kp->imr1_val << MAX_COLS);
>> + }
>> + }
>> +
>> + /*
>> + * Obtain the interrupt trigger type specified and verify against the
>> + * possible values specified in the DT binding.
>> + */
>> + of_property_read_u32(np, "key-interrupt-trigger-type",
>> + &dt_val);
>> + if ((dt_val == 0) || (dt_val > KPEMR_EDGETYPE_MAX)) {
>> + dev_err(dev, "Invalid interrupt trigger type %d\n", dt_val);
>> + return -EINVAL;
>> + }
>> + /* Initialize the KPEMR Keypress Edge Mode Registers */
>> + kp->kpemr = 0;
>> + for (i = 0; i <= 30; i = i + 2)
>> + kp->kpemr |= (dt_val << i);
>> +
>> + /*
>> + * Obtain the Status filter debounce value and verify against the
>> + * possible values specified in the DT binding.
>> + */
>> + of_property_read_u32(np, "status-debounce-filter-period",
>> + &dt_val);
>> + if (dt_val > KPCR_STATUSFILTERTYPE_MAX) {
>> + dev_err(dev, "Invalid Status filter debounce value %d\n",
>> + dt_val);
>> + return -EINVAL;
>> + }
>> + kp->kpcr |= dt_val << KPCR_STATUSFILTERTYPE_SHIFT;
>> +
>> +
>> + /*
>> + * Obtain the Column filter debounce value and verify against the
>> + * possible values specified in the DT binding.
>> + */
>> + of_property_read_u32(np, "col-debounce-filter-period",
>> + &dt_val);
>> +
>> + if (dt_val > KPCR_COLFILTERTYPE_MAX) {
>> + dev_err(dev, "Invalid Column filter debounce value %d\n",
>> + dt_val);
>> + return -EINVAL;
>> + }
>> + kp->kpcr |= dt_val << KPCR_COLFILTERTYPE_SHIFT;
>> +
>> + /*
>> + * Determine between the row and column,
>> + * which should be configured as output.
>> + */
>> + if (of_property_read_bool(np, "row-output-enabled")) {
>> + /*
>> + * Set RowOContrl or ColumnOContrl in KPIOR
>> + * to the number of pins to drive as outputs
>> + */
>> + kp->kpior = (((1 << kp->n_rows) - 1) <<
>> + KPIOR_ROWOCONTRL_SHIFT);
>> + } else {
>> + kp->kpior = (((1 << kp->n_cols) - 1) <<
>> + KPIOR_COLUMNOCONTRL_SHIFT);
>> + }
>> +
>> + /*
>> + * Determine if the scan pull up needs to be enabled
>> + */
>> + if (of_property_read_bool(np, "pull-up-enabled"))
>> + kp->kpcr |= KPCR_MODE;
>> +
>> + dev_dbg(dev, "n_rows=%d n_col=%d kpcr=%x kpior=%x kpemr=%x\n",
>> + kp->n_rows, kp->n_cols,
>> + kp->kpcr, kp->kpior, kp->kpemr);
>> +
>> + return 0;
>> +}
>> +
>> +
>> +static int bcm_kp_probe(struct platform_device *pdev)
>> +{
>> + struct bcm_kp *kp;
>> + struct input_dev *input_dev;
>> + struct resource *res;
>> + int error;
>> +
>> + kp = devm_kzalloc(&pdev->dev, sizeof(*kp),
>> + GFP_KERNEL);
>> + if (!kp)
>> + return -ENOMEM;
>> +
>> + input_dev = devm_input_allocate_device(&pdev->dev);
>> + if (!input_dev) {
>> + dev_err(&pdev->dev, "failed to allocate the input device\n");
>> + return -ENOMEM;
>> + }
>> + __set_bit(EV_KEY, input_dev->evbit);
>> + __set_bit(EV_REP, input_dev->evbit);
>> + input_dev->rep[REP_PERIOD] = KEY_REPEAT_PERIOD;
>> + input_dev->rep[REP_DELAY] = KEY_REPEAT_DELAY;
>
> That does not do what you think: if you set up custom delay and period
> you are supposed to supply your own timer as well. Either adjust values
> after registering input device, or leave defaults.
>
> Also it might be a good idea to have "linux,autorepeat" DT property to
> control it.
>
I'll look into this in more detail to understand.

>> + input_dev->name = pdev->name;
>> + input_dev->phys = "keypad/input0";
>> + input_dev->dev.parent = &pdev->dev;
>> + input_dev->open = bcm_kp_open;
>> + input_dev->close = bcm_kp_close;
>> +
>> + input_dev->id.bustype = BUS_HOST;
>> + input_dev->id.vendor = 0x0001;
>> + input_dev->id.product = 0x0001;
>> + input_dev->id.version = 0x0100;
>> +
>> + input_set_drvdata(input_dev, kp);
>> +
>> + kp->input_dev = input_dev;
>> +
>> + platform_set_drvdata(pdev, kp);
>> +
>> + error = bcm_kp_matrix_key_parse_dt(kp);
>> + if (error)
>> + return error;
>> +
>> + error = matrix_keypad_build_keymap(NULL, NULL,
>> + kp->n_rows,
>> + kp->n_cols,
>> + NULL, input_dev);
>> + if (error) {
>> + dev_err(&pdev->dev, "failed to build keymap\n");
>> + return error;
>> + }
>> +
>> + /* Get the KEYPAD base address */
>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + if (!res) {
>> + dev_err(&pdev->dev, "Missing keypad base address resource\n");
>> + return -ENODEV;
>> + }
>> +
>> + kp->base = devm_ioremap_resource(&pdev->dev, res);
>> + if (IS_ERR(kp->base))
>> + return PTR_ERR(kp->base);
>> +
>> + /* Enable clock */
>> +
>> + kp->clk = devm_clk_get(&pdev->dev, "peri_clk");
>> + if (IS_ERR(kp->clk))
>> + dev_info(&pdev->dev,
>> + "No clock specified. Assuming it's enabled\n");
>> + else {
>> + unsigned int desired_rate;
>> + long actual_rate;
>> +
>> + error = of_property_read_u32(pdev->dev.of_node,
>> + "clock-frequency", &desired_rate);
>> + if (error < 0)
>> + desired_rate = DEFAULT_CLK_HZ;
>> +
>> + actual_rate = clk_round_rate(kp->clk, desired_rate);
>> + if (actual_rate <= 0)
>> + return -EINVAL;
>> +
>> + error = clk_set_rate(kp->clk, actual_rate);
>> + if (error)
>> + return -EINVAL;
>> +
>> + error = clk_prepare_enable(kp->clk);
>> + if (error)
>> + return -EINVAL;
>> + }
>> +
>> + /* Put the kp into a known sane state */
>> + bcm_kp_stop(kp);
>> +
>> + kp->irq = platform_get_irq(pdev, 0);
>> + if (kp->irq < 0) {
>> + dev_err(&pdev->dev, "no IRQ specified\n");
>> + return -EINVAL;
>> + }
>> +
>> + error = devm_request_threaded_irq(&pdev->dev, kp->irq, NULL,
>> + bcm_kp_isr_thread,
>> + IRQF_ONESHOT, pdev->name, kp);
>> + if (error) {
>> + dev_err(&pdev->dev, "failed to request IRQ\n");
>> + return error;
>> + }
>> +
>> + error = input_register_device(input_dev);
>> + if (error) {
>> + dev_err(&pdev->dev, "failed to register input device\n");
>> + return error;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +/* Called to perform module cleanup when the module is unloaded. */
>> +static int bcm_kp_remove(struct platform_device *pdev)
>> +{
>> + struct bcm_kp *kp = platform_get_drvdata(pdev);
>> +
>> + pr_info("bcm_kp_remove\n");
>> +
>> + /* Unregister everything */
>> + input_unregister_device(kp->input_dev);
>> + clk_disable_unprepare(kp->clk);
>
> You already calling clk_disable_unprepare() as part of bcm_kp_close()
> (in stop()), so you do not need it here. input_unregister_device() will
> also be called automatically since you are using managed input device,
> so please remove bcm_kp_remove altogether.
>
OK, will remove. That's an easy thing to do.

>> +
>> + return 0;
>> +}
>> +
>> +static const struct of_device_id bcm_kp_of_match[] = {
>> + { .compatible = "brcm,bcm-keypad" },
>> + { },
>> +};
>> +MODULE_DEVICE_TABLE(of, bcm_kp_of_match);
>> +
>> +static struct platform_driver bcm_kp_device_driver = {
>> + .probe = bcm_kp_probe,
>> + .remove = bcm_kp_remove,
>> + .driver = {
>> + .name = "bcm-keypad",
>> + .of_match_table = of_match_ptr(bcm_kp_of_match),
>> + }
>> +};
>> +
>> +module_platform_driver(bcm_kp_device_driver);
>> +
>> +MODULE_AUTHOR("Broadcom Corporation");
>> +MODULE_DESCRIPTION("BCM Keypad Driver");
>> +MODULE_LICENSE("GPL");
>> --
>> 2.2.2
>>
>
> Thanks.
>



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