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SubjectRe: [PATCH 2/2] Input: bcm-keypad: Add Broadcom keypad controller
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...).

> +
> + 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.

> + 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.

> +
> + 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.

--
Dmitry


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