diff options
Diffstat (limited to 'drivers/input/keyboard/bcm-keypad.c')
| -rw-r--r-- | drivers/input/keyboard/bcm-keypad.c | 454 |
1 files changed, 454 insertions, 0 deletions
diff --git a/drivers/input/keyboard/bcm-keypad.c b/drivers/input/keyboard/bcm-keypad.c new file mode 100644 index 000000000..2b771c3a5 --- /dev/null +++ b/drivers/input/keyboard/bcm-keypad.c @@ -0,0 +1,454 @@ +/* + * 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/bitops.h> +#include <linux/clk.h> +#include <linux/gfp.h> +#include <linux/io.h> +#include <linux/input.h> +#include <linux/input/matrix_keypad.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/stddef.h> +#include <linux/types.h> + +#define DEFAULT_CLK_HZ 31250 +#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_BOTH 3 + +#define KPSSR0_OFFSET 0x000000A0 +#define KPSSR1_OFFSET 0x000000A4 +#define KPSSRN_OFFSET(reg_n) (KPSSR0_OFFSET + 4 * (reg_n)) +#define KPIMR0_OFFSET 0x000000B0 +#define KPIMR1_OFFSET 0x000000B4 +#define KPICR0_OFFSET 0x000000B8 +#define KPICR1_OFFSET 0x000000BC +#define KPICRN_OFFSET(reg_n) (KPICR0_OFFSET + 4 * (reg_n)) +#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_SSRN(bit_nr, reg_n) (((bit_nr) >> 3) + 4 * (reg_n)) +#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 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 void bcm_kp_report_keys(struct bcm_kp *kp, int reg_num, int pull_mode) +{ + unsigned long state, change; + int bit_nr; + int key_press; + int row, col; + unsigned int keycode; + + /* Clear interrupts */ + writel(0xFFFFFFFF, kp->base + KPICRN_OFFSET(reg_num)); + + state = readl(kp->base + KPSSRN_OFFSET(reg_num)); + change = kp->last_state[reg_num] ^ state; + kp->last_state[reg_num] = 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_SSRN(bit_nr, reg_num); + col = BIT_TO_COL(bit_nr); + keycode = bcm_kp_get_keycode(kp, row, col); + input_report_key(kp->input_dev, keycode, key_press); + } +} + +static irqreturn_t bcm_kp_isr_thread(int irq, void *dev_id) +{ + struct bcm_kp *kp = dev_id; + int pull_mode = (kp->kpcr >> KPCR_MODE_SHIFT) & KPCR_MODE_MASK; + int reg_num; + + for (reg_num = 0; reg_num <= 1; reg_num++) + bcm_kp_report_keys(kp, reg_num, pull_mode); + + input_sync(kp->input_dev); + + return IRQ_HANDLED; +} + +static int bcm_kp_start(struct bcm_kp *kp) +{ + int error; + + if (kp->clk) { + 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); + + if (kp->clk) + 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; + unsigned int num_rows, col_mask, rows_set; + + /* Initialize the KPCR Keypad Configuration Register */ + kp->kpcr = KPCR_STATUSFILTERENABLE | KPCR_COLFILTERENABLE; + + error = matrix_keypad_parse_properties(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 */ + + /* + * 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; + } + + /* Initialize the KPEMR Keypress Edge Mode Registers */ + /* Trigger on both edges */ + kp->kpemr = 0; + for (i = 0; i <= 30; i += 2) + kp->kpemr |= (KPEMR_EDGETYPE_BOTH << 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); + + /* Enable auto repeat feature of Linux input subsystem */ + if (of_property_read_bool(pdev->dev.of_node, "autorepeat")) + __set_bit(EV_REP, input_dev->evbit); + + 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; + + 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)) { + error = PTR_ERR(kp->clk); + if (error != -ENOENT) { + if (error != -EPROBE_DEFER) + dev_err(&pdev->dev, "Failed to get clock\n"); + return error; + } + dev_dbg(&pdev->dev, + "No clock specified. Assuming it's enabled\n"); + kp->clk = NULL; + } 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 error; + + error = clk_prepare_enable(kp->clk); + if (error) + return error; + } + + /* Put the kp into a known sane state */ + bcm_kp_stop(kp); + + kp->irq = platform_get_irq(pdev, 0); + if (kp->irq < 0) + 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; +} + +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, + .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 v2"); |