Hi Dmitry, On Wed, Feb 13, 2013 at 12:02 PM, Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> wrote: > Hi SImon, > > On Tue, Feb 12, 2013 at 06:42:26PM -0800, Simon Glass wrote: >> Use the key-matrix layer to interpret key scan information from the EC >> and inject input based on the FDT-supplied key map. This driver registers >> itself with the ChromeOS EC driver to perform communications. >> >> Additional FDT bindings are provided to specify rows/columns and the >> auto-repeat information. >> >> Signed-off-by: Simon Glass <sjg@xxxxxxxxxxxx> >> Signed-off-by: Luigi Semenzato <semenzato@xxxxxxxxxxxx> >> Signed-off-by: Vincent Palatin <vpalatin@xxxxxxxxxxxx> >> --- >> Changes in v2: >> - Remove use of __devinit/__devexit >> - Use function to read matrix-keypad parameters from DT >> - Remove key autorepeat parameters from DT binding and driver >> - Use unsigned int for rows/cols Thanks for all the review comments. >> >> .../devicetree/bindings/input/cros-ec-keyb.txt | 72 ++++ >> drivers/input/keyboard/Kconfig | 12 + >> drivers/input/keyboard/Makefile | 1 + >> drivers/input/keyboard/cros_ec_keyb.c | 394 +++++++++++++++++++++ >> 4 files changed, 479 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/input/cros-ec-keyb.txt >> create mode 100644 drivers/input/keyboard/cros_ec_keyb.c >> >> diff --git a/Documentation/devicetree/bindings/input/cros-ec-keyb.txt b/Documentation/devicetree/bindings/input/cros-ec-keyb.txt >> new file mode 100644 >> index 0000000..0f6355c >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/input/cros-ec-keyb.txt >> @@ -0,0 +1,72 @@ >> +ChromeOS EC Keyboard >> + >> +Google's ChromeOS EC Keyboard is a simple matrix keyboard implemented on >> +a separate EC (Embedded Controller) device. It provides a message for reading >> +key scans from the EC. These are then converted into keycodes for processing >> +by the kernel. >> + >> +This binding is based on matrix-keymap.txt and extends/modifies it as follows: >> + >> +Required properties: >> +- compatible: "google,cros-ec-keyb" >> + >> +Optional properties: >> +- google,needs-ghost-filter: True to enable a ghost filter for the matrix >> +keyboard. This is recommended if the EC does not have its own logic or >> +hardware for this. >> + >> + >> +Example: >> + >> +cros-ec-keyb { >> + compatible = "google,cros-ec-keyb"; >> + keypad,num-rows = <8>; >> + keypad,num-columns = <13>; >> + google,needs-ghost-filter; >> + /* >> + * Keymap entries take the form of 0xRRCCKKKK where >> + * RR=Row CC=Column KKKK=Key Code >> + * The values below are for a US keyboard layout and >> + * are taken from the Linux driver. Note that the >> + * 102ND key is not used for US keyboards. >> + */ >> + linux,keymap = < >> + /* CAPSLCK F1 B F10 */ >> + 0x0001003a 0x0002003b 0x00030030 0x00040044 >> + /* N = R_ALT ESC */ >> + 0x00060031 0x0008000d 0x000a0064 0x01010001 >> + /* F4 G F7 H */ >> + 0x0102003e 0x01030022 0x01040041 0x01060023 >> + /* ' F9 BKSPACE L_CTRL */ >> + 0x01080028 0x01090043 0x010b000e 0x0200001d >> + /* TAB F3 T F6 */ >> + 0x0201000f 0x0202003d 0x02030014 0x02040040 >> + /* ] Y 102ND [ */ >> + 0x0205001b 0x02060015 0x02070056 0x0208001a >> + /* F8 GRAVE F2 5 */ >> + 0x02090042 0x03010029 0x0302003c 0x03030006 >> + /* F5 6 - \ */ >> + 0x0304003f 0x03060007 0x0308000c 0x030b002b >> + /* R_CTRL A D F */ >> + 0x04000061 0x0401001e 0x04020020 0x04030021 >> + /* S K J ; */ >> + 0x0404001f 0x04050025 0x04060024 0x04080027 >> + /* L ENTER Z C */ >> + 0x04090026 0x040b001c 0x0501002c 0x0502002e >> + /* V X , M */ >> + 0x0503002f 0x0504002d 0x05050033 0x05060032 >> + /* L_SHIFT / . SPACE */ >> + 0x0507002a 0x05080035 0x05090034 0x050B0039 >> + /* 1 3 4 2 */ >> + 0x06010002 0x06020004 0x06030005 0x06040003 >> + /* 8 7 0 9 */ >> + 0x06050009 0x06060008 0x0608000b 0x0609000a >> + /* L_ALT DOWN RIGHT Q */ >> + 0x060a0038 0x060b006c 0x060c006a 0x07010010 >> + /* E R W I */ >> + 0x07020012 0x07030013 0x07040011 0x07050017 >> + /* U R_SHIFT P O */ >> + 0x07060016 0x07070036 0x07080019 0x07090018 >> + /* UP LEFT */ >> + 0x070b0067 0x070c0069>; >> +}; >> diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig >> index 078305e..3a70be7 100644 >> --- a/drivers/input/keyboard/Kconfig >> +++ b/drivers/input/keyboard/Kconfig >> @@ -628,4 +628,16 @@ config KEYBOARD_W90P910 >> To compile this driver as a module, choose M here: the >> module will be called w90p910_keypad. >> >> +config KEYBOARD_CROS_EC >> + tristate "ChromeOS EC keyboard" >> + select INPUT_MATRIXKMAP >> + select MFD_CROS_EC > > Is this select safe? I.e. does MFD_CROS_EC depend on anything else? I'll remove it, since it isn't required, and it's true that it does need other things. > >> + help >> + Say Y here to enable the matrix keyboard used by ChromeOS devices >> + and implemented on the ChromeOS EC. You must enable one bus option >> + (MFD_CROS_EC_I2C or MFD_CROS_EC_SPI) to use this. >> + >> + To compile this driver as a module, choose M here: the >> + module will be called cros_ec_keyb. >> + >> endif >> diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile >> index 49b1645..0c43e8c 100644 >> --- a/drivers/input/keyboard/Makefile >> +++ b/drivers/input/keyboard/Makefile >> @@ -11,6 +11,7 @@ obj-$(CONFIG_KEYBOARD_AMIGA) += amikbd.o >> obj-$(CONFIG_KEYBOARD_ATARI) += atakbd.o >> obj-$(CONFIG_KEYBOARD_ATKBD) += atkbd.o >> obj-$(CONFIG_KEYBOARD_BFIN) += bf54x-keys.o >> +obj-$(CONFIG_KEYBOARD_CROS_EC) += cros_ec_keyb.o >> obj-$(CONFIG_KEYBOARD_DAVINCI) += davinci_keyscan.o >> obj-$(CONFIG_KEYBOARD_EP93XX) += ep93xx_keypad.o >> obj-$(CONFIG_KEYBOARD_GOLDFISH_EVENTS) += goldfish_events.o >> diff --git a/drivers/input/keyboard/cros_ec_keyb.c b/drivers/input/keyboard/cros_ec_keyb.c >> new file mode 100644 >> index 0000000..43e5be2 >> --- /dev/null >> +++ b/drivers/input/keyboard/cros_ec_keyb.c >> @@ -0,0 +1,394 @@ >> +/* >> + * ChromeOS EC keyboard driver >> + * >> + * Copyright (C) 2012 Google, Inc >> + * >> + * This software is licensed under the terms of the GNU General Public >> + * License version 2, as published by the Free Software Foundation, and >> + * may be copied, distributed, and modified under those terms. >> + * >> + * This program is distributed in the hope that it will be useful, >> + * but WITHOUT ANY WARRANTY; without even the implied warranty of >> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the >> + * GNU General Public License for more details. >> + * >> + * This driver uses the Chrome OS EC byte-level message-based protocol for >> + * communicating the keyboard state (which keys are pressed) from a keyboard EC >> + * to the AP over some bus (such as i2c, lpc, spi). The EC does debouncing, >> + * but everything else (including deghosting) is done here. The main >> + * motivation for this is to keep the EC firmware as simple as possible, since >> + * it cannot be easily upgraded and EC flash/IRAM space is relatively >> + * expensive. >> + */ >> + >> +#include <linux/module.h> >> +#include <linux/i2c.h> >> +#include <linux/input.h> >> +#include <linux/kernel.h> >> +#include <linux/notifier.h> >> +#include <linux/platform_device.h> >> +#include <linux/slab.h> >> +#include <linux/input/matrix_keypad.h> >> +#include <linux/mfd/cros_ec.h> >> +#include <linux/mfd/cros_ec_commands.h> >> + >> +/* >> + * @rows: Number of rows in the keypad >> + * @cols: Number of columns in the keypad >> + * @row_shift: log2 or number of rows, rounded up >> + * @keymap_data: Matrix keymap data used to convert to keyscan values >> + * @ghost_filter: true to enable the matrix key-ghosting filter >> + * @old_state: Previous state of the keyboard matrix (used to calc deltas) >> + * @dev: Device pointer >> + * @idev: Input device >> + * @ec: Top level ChromeOS device to use to talk to EC >> + * @event_notifier: interrupt event notifier for transport devices >> + * @wake_notifier: wake notfier for client devices (e.g. keyboard). This >> + * indicates to sub-drivers that we have woken up from resume but we >> + * were not a wakeup source. >> + */ >> +struct cros_ec_keyb { >> + unsigned int rows; >> + unsigned int cols; >> + int row_shift; >> + const struct matrix_keymap_data *keymap_data; >> + bool ghost_filter; >> + /* >> + * old_state[matrix code] is 1 when the most recent (valid) >> + * communication with the keyboard indicated that the key at row/col >> + * was in the pressed state. >> + */ >> + uint8_t *old_state; >> + >> + struct device *dev; >> + struct input_dev *idev; >> + struct cros_ec_device *ec; >> + struct notifier_block notifier; >> + struct notifier_block wake_notifier; >> +}; >> + >> + >> +/* >> + * Sends a single key event to the input layer. >> + */ >> +static inline void cros_ec_keyb_send_key_event(struct cros_ec_keyb *ckdev, >> + int row, int col, int pressed) >> +{ >> + struct input_dev *idev = ckdev->idev; >> + int code = MATRIX_SCAN_CODE(row, col, ckdev->row_shift); >> + const unsigned short *keycodes = idev->keycode; >> + >> + input_report_key(idev, keycodes[code], pressed); >> +} >> + >> +/* >> + * Returns true when there is at least one combination of pressed keys that >> + * results in ghosting. >> + */ >> +static bool cros_ec_keyb_has_ghosting(struct cros_ec_keyb *ckdev, uint8_t *buf) >> +{ >> + int col, row; >> + int mask; >> + int pressed_in_row[ckdev->rows]; >> + int row_has_teeth[ckdev->rows]; >> + >> + memset(pressed_in_row, '\0', sizeof(pressed_in_row)); >> + memset(row_has_teeth, '\0', sizeof(row_has_teeth)); >> + /* >> + * Ghosting happens if for any pressed key X there are other keys >> + * pressed both in the same row and column of X as, for instance, >> + * in the following diagram: >> + * >> + * . . Y . g . >> + * . . . . . . >> + * . . . . . . >> + * . . X . Z . >> + * >> + * In this case only X, Y, and Z are pressed, but g appears to be >> + * pressed too (see Wikipedia). >> + * >> + * We can detect ghosting in a single pass (*) over the keyboard state >> + * by maintaining two arrays. pressed_in_row counts how many pressed >> + * keys we have found in a row. row_has_teeth is true if any of the >> + * pressed keys for this row has other pressed keys in its column. If >> + * at any point of the scan we find that a row has multiple pressed >> + * keys, and at least one of them is at the intersection with a column >> + * with multiple pressed keys, we're sure there is ghosting. >> + * Conversely, if there is ghosting, we will detect such situation for >> + * at least one key during the pass. >> + * >> + * (*) This looks linear in the number of keys, but it's not. We can >> + * cheat because the number of rows is small. >> + */ >> + for (row = 0; row < ckdev->rows; row++) { >> + mask = 1 << row; >> + for (col = 0; col < ckdev->cols; col++) { >> + if (buf[col] & mask) { >> + pressed_in_row[row] += 1; > > Just ++ please. Done > >> + row_has_teeth[row] |= buf[col] & ~mask; >> + if (pressed_in_row[row] > 1 && >> + row_has_teeth[row]) { >> + /* ghosting */ >> + dev_dbg(ckdev->dev, >> + "ghost found at: r%d c%d," >> + " pressed %d, teeth 0x%x\n", > > Please do not break message strings even if they push you over 80 columns. Done > >> + row, col, pressed_in_row[row], >> + row_has_teeth[row]); >> + return true; >> + } > > I am confused why you need pressed_in_row and row_has_teeth arrays as > you are working with one row at a time. Hmmm I never did quite grok that code. I can't see why we need an array, so have changed it. > > Also, can we move inner loop into a separate function? Done > >> + } >> + } >> + } >> + return false; >> +} >> + >> +/* >> + * Compares the new keyboard state to the old one and produces key >> + * press/release events accordingly. The keyboard state is 13 bytes (one byte >> + * per column) >> + */ >> +static void cros_ec_keyb_process(struct cros_ec_keyb *ckdev, >> + uint8_t *kb_state, int len) >> +{ >> + int col, row; >> + int new_state; >> + int num_cols; >> + >> + num_cols = len; >> + >> + if (ckdev->ghost_filter && cros_ec_keyb_has_ghosting(ckdev, kb_state)) { >> + /* >> + * Simple-minded solution: ignore this state. The obvious >> + * improvement is to only ignore changes to keys involved in >> + * the ghosting, but process the other changes. >> + */ >> + dev_dbg(ckdev->dev, "ghosting found\n"); >> + return; >> + } >> + >> + for (col = 0; col < ckdev->cols; col++) { >> + for (row = 0; row < ckdev->rows; row++) { >> + int code = MATRIX_SCAN_CODE(row, col, ckdev->row_shift); >> + >> + new_state = kb_state[col] & (1 << row); >> + if (!!new_state != ckdev->old_state[code]) { >> + dev_dbg(ckdev->dev, >> + "changed: [r%d c%d]: byte %02x\n", >> + row, col, new_state); >> + } >> + if (new_state && !ckdev->old_state[code]) { >> + /* key press */ >> + cros_ec_keyb_send_key_event(ckdev, row, col, 1); >> + ckdev->old_state[code] = 1; >> + } else if (!new_state && ckdev->old_state[code]) { >> + /* key release */ >> + cros_ec_keyb_send_key_event(ckdev, row, col, 0); >> + ckdev->old_state[code] = 0; >> + } > > Should not all of the above be: > > if (!!new_state != test_bit(code, dev->key)) { > dev_dbg(ckdev->dev, > "changed: [r%d c%d]: byte %02x\n", > row, col, new_state); > > input_report_key(idev, keycodes[code], new_state); > } > > and yo can get rid of old_state altogether? That's cool. Done. > >> + } >> + } >> + input_sync(ckdev->idev); >> +} >> + >> +static int cros_ec_keyb_open(struct input_dev *dev) >> +{ >> + struct cros_ec_keyb *ckdev = input_get_drvdata(dev); >> + int ret; >> + >> + ret = blocking_notifier_chain_register(&ckdev->ec->event_notifier, >> + &ckdev->notifier); >> + if (ret) >> + return ret; >> + ret = blocking_notifier_chain_register(&ckdev->ec->wake_notifier, >> + &ckdev->wake_notifier); >> + if (ret) { >> + blocking_notifier_chain_unregister( >> + &ckdev->ec->event_notifier, &ckdev->notifier); >> + return ret; >> + } >> + >> + return 0; >> +} >> + >> +static void cros_ec_keyb_close(struct input_dev *dev) >> +{ >> + struct cros_ec_keyb *ckdev = input_get_drvdata(dev); >> + >> + blocking_notifier_chain_unregister(&ckdev->ec->event_notifier, >> + &ckdev->notifier); >> + blocking_notifier_chain_unregister(&ckdev->ec->wake_notifier, >> + &ckdev->wake_notifier); > > Why is this done via a notifier instead of regular resume method? Because we only call the notifer in resume when we were not waking on a keyboard event. We use it to flush the keyboard. It was a late change so there might be a better way, but this driver does not have a resume handler. > >> +} >> + >> +static int cros_ec_keyb_get_state(struct cros_ec_keyb *ckdev, uint8_t *kb_state) >> +{ >> + return ckdev->ec->command_recv(ckdev->ec, EC_CMD_MKBP_STATE, >> + kb_state, ckdev->cols); >> +} >> + >> +static int cros_ec_keyb_work(struct notifier_block *nb, >> + unsigned long state, void *_notify) >> +{ >> + int ret; >> + struct cros_ec_keyb *ckdev = container_of(nb, struct cros_ec_keyb, >> + notifier); >> + uint8_t kb_state[ckdev->cols]; >> + >> + ret = cros_ec_keyb_get_state(ckdev, kb_state); >> + if (ret >= 0) >> + cros_ec_keyb_process(ckdev, kb_state, ret); >> + >> + return NOTIFY_DONE; >> +} >> + >> +/* On resume, clear any keys in the buffer */ >> +static int cros_ec_keyb_clear_keyboard(struct notifier_block *nb, >> + unsigned long state, void *_notify) >> +{ >> + struct cros_ec_keyb *ckdev = container_of(nb, struct cros_ec_keyb, >> + wake_notifier); >> + uint8_t old_state[ckdev->cols]; >> + uint8_t new_state[ckdev->cols]; >> + unsigned long duration; >> + int i, ret; >> + >> + /* >> + * Keep reading until we see that the scan state does not change. >> + * That indicates that we are done. >> + * >> + * Assume that the EC keyscan buffer is at most 32 deep. >> + */ >> + duration = jiffies; >> + ret = cros_ec_keyb_get_state(ckdev, new_state); >> + for (i = 1; !ret && i < 32; i++) { >> + memcpy(old_state, new_state, sizeof(old_state)); >> + ret = cros_ec_keyb_get_state(ckdev, new_state); >> + if (0 == memcmp(old_state, new_state, sizeof(old_state))) >> + break; >> + } >> + duration = jiffies - duration; >> + dev_info(ckdev->dev, "Discarded %d keyscan(s) in %dus\n", i, >> + jiffies_to_usecs(duration)); >> + >> + return 0; >> +} >> + >> +static const struct of_device_id cros_ec_kbc_of_match[] = { >> + { .compatible = "google,cros-ec-keyb", }, >> + { }, >> +}; >> + >> +static int cros_ec_keyb_probe(struct platform_device *pdev) >> +{ >> + struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent); >> + struct device *dev = ec->dev; >> + struct cros_ec_keyb *ckdev = NULL; >> + struct input_dev *idev = NULL; >> + struct device_node *np; >> + int err; >> + >> + np = of_find_matching_node(NULL, cros_ec_kbc_of_match); > > And if we don't find it? Added error checking. > >> + >> + ckdev = kzalloc(sizeof(*ckdev), GFP_KERNEL); >> + if (!ckdev) { >> + dev_err(dev, "cannot allocate memory for ckdev\n"); >> + return -ENOMEM; >> + } >> + pdev->dev.of_node = np; > > Huh? I'd expect the platform device be fully set up (including DT data) > before the driver is called. This is a child of the mfd driver cros_ec, so I don't think that works. Or maybe I'm just not sure how to plumb it in so it is automatic. Or maybe I just need to add the id to the device info below? > >> + err = matrix_keypad_parse_of_params(&pdev->dev, &ckdev->rows, >> + &ckdev->cols); >> + if (err) >> + goto fail_alloc_dev; >> + >> + idev = input_allocate_device(); >> + if (!idev) { >> + err = -ENOMEM; >> + dev_err(dev, "cannot allocate memory for input device\n"); >> + goto fail_alloc_dev; >> + } >> + >> + ckdev->ec = ec; >> + ckdev->notifier.notifier_call = cros_ec_keyb_work; >> + ckdev->wake_notifier.notifier_call = cros_ec_keyb_clear_keyboard; >> + ckdev->dev = dev; >> + dev_set_drvdata(&pdev->dev, ckdev); >> + >> + idev->name = ec->get_name(ec); >> + idev->phys = ec->get_phys_name(ec); >> + __set_bit(EV_REP, idev->evbit); >> + >> + idev->id.bustype = BUS_VIRTUAL; >> + idev->id.version = 1; >> + idev->id.product = 0; >> + idev->dev.parent = &pdev->dev; >> + idev->open = cros_ec_keyb_open; >> + idev->close = cros_ec_keyb_close; >> + >> + ckdev->ghost_filter = of_property_read_bool(np, >> + "google,needs-ghost-filter"); >> + >> + err = matrix_keypad_build_keymap(NULL, NULL, ckdev->rows, ckdev->cols, >> + NULL, idev); >> + if (err) { >> + dev_err(dev, "cannot build key matrix\n"); >> + goto fail_matrix; >> + } >> + >> + ckdev->row_shift = get_count_order(ckdev->cols); >> + ckdev->old_state = kzalloc(idev->keycodemax, GFP_KERNEL); >> + if (!ckdev->old_state) { >> + dev_err(dev, "Cannot allocate memory for old_state\n"); >> + err = -ENOMEM; >> + goto fail_old_state; >> + } > > Not needed I believe. Dropped. > >> + >> + input_set_capability(idev, EV_MSC, MSC_SCAN); >> + input_set_drvdata(idev, ckdev); >> + ckdev->idev = idev; >> + err = input_register_device(ckdev->idev); >> + if (err) { >> + dev_err(dev, "cannot register input device\n"); >> + goto fail_register; >> + } >> + >> + return 0; >> + >> +fail_register: >> + kfree(ckdev->old_state); >> +fail_old_state: >> + kfree(idev->keycode); >> +fail_matrix: >> + input_free_device(idev); >> +fail_alloc_dev: >> + kfree(ckdev); >> + return err; >> +} >> + >> +static int cros_ec_keyb_remove(struct platform_device *pdev) >> +{ >> + struct cros_ec_keyb *ckdev = dev_get_drvdata(&pdev->dev); > > platform_get_drvdata() please. Done > >> + struct input_dev *idev = ckdev->idev; >> + >> + /* I believe we leak a matrix_keymap here */ > > How? It is devm-managed. Original code might pre-date that. Removed comment. > >> + input_unregister_device(idev); >> + kfree(ckdev->old_state); >> + kfree(idev->keycode); > > And since it is devm-managed you should not free it yourself. Actually > idev is most likely gone at this point already. Yes, done. > >> + input_free_device(idev); > > Do not call input_free_device() after input_unregister_device(). Done > >> + kfree(ckdev); >> + >> + return 0; >> +} >> + >> +static struct platform_driver cros_ec_keyb_driver = { >> + .probe = cros_ec_keyb_probe, >> + .remove = cros_ec_keyb_remove, >> + .driver = { >> + .name = "cros-ec-keyb", >> + }, >> +}; >> + >> +module_platform_driver(cros_ec_keyb_driver); >> + >> +MODULE_LICENSE("GPL"); >> +MODULE_DESCRIPTION("ChromeOS EC keyboard driver"); >> +MODULE_ALIAS("platform:cros-ec-keyb"); >> -- >> 1.8.1 >> > > Thanks. > > -- > Dmitry I'll send a new version so that the above is done, at least. Regards, Simon -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html