diff options
Diffstat (limited to 'drivers/staging/olpc_dcon/olpc_dcon_xo_1.c')
| -rw-r--r-- | drivers/staging/olpc_dcon/olpc_dcon_xo_1.c | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/drivers/staging/olpc_dcon/olpc_dcon_xo_1.c b/drivers/staging/olpc_dcon/olpc_dcon_xo_1.c new file mode 100644 index 000000000000..0c5a10c69401 --- /dev/null +++ b/drivers/staging/olpc_dcon/olpc_dcon_xo_1.c @@ -0,0 +1,205 @@ +/* + * Mainly by David Woodhouse, somewhat modified by Jordan Crouse + * + * Copyright © 2006-2007 Red Hat, Inc. + * Copyright © 2006-2007 Advanced Micro Devices, Inc. + * Copyright © 2009 VIA Technology, Inc. + * Copyright (c) 2010 Andres Salomon <dilinger@queued.net> + * + * This program is free software. You can redistribute it and/or + * modify it under the terms of version 2 of the GNU General Public + * License as published by the Free Software Foundation. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/cs5535.h> +#include <linux/gpio.h> +#include <linux/delay.h> +#include <asm/olpc.h> + +#include "olpc_dcon.h" + +static int dcon_init_xo_1(struct dcon_priv *dcon) +{ + unsigned char lob; + + if (gpio_request(OLPC_GPIO_DCON_STAT0, "OLPC-DCON")) { + pr_err("failed to request STAT0 GPIO\n"); + return -EIO; + } + if (gpio_request(OLPC_GPIO_DCON_STAT1, "OLPC-DCON")) { + pr_err("failed to request STAT1 GPIO\n"); + goto err_gp_stat1; + } + if (gpio_request(OLPC_GPIO_DCON_IRQ, "OLPC-DCON")) { + pr_err("failed to request IRQ GPIO\n"); + goto err_gp_irq; + } + if (gpio_request(OLPC_GPIO_DCON_LOAD, "OLPC-DCON")) { + pr_err("failed to request LOAD GPIO\n"); + goto err_gp_load; + } + if (gpio_request(OLPC_GPIO_DCON_BLANK, "OLPC-DCON")) { + pr_err("failed to request BLANK GPIO\n"); + goto err_gp_blank; + } + + /* Turn off the event enable for GPIO7 just to be safe */ + cs5535_gpio_clear(OLPC_GPIO_DCON_IRQ, GPIO_EVENTS_ENABLE); + + /* + * Determine the current state by reading the GPIO bit; earlier + * stages of the boot process have established the state. + * + * Note that we read GPIO_OUTPUT_VAL rather than GPIO_READ_BACK here; + * this is because OFW will disable input for the pin and set a value.. + * READ_BACK will only contain a valid value if input is enabled and + * then a value is set. So, future readings of the pin can use + * READ_BACK, but the first one cannot. Awesome, huh? + */ + dcon->curr_src = cs5535_gpio_isset(OLPC_GPIO_DCON_LOAD, GPIO_OUTPUT_VAL) + ? DCON_SOURCE_CPU + : DCON_SOURCE_DCON; + dcon->pending_src = dcon->curr_src; + + /* Set the directions for the GPIO pins */ + gpio_direction_input(OLPC_GPIO_DCON_STAT0); + gpio_direction_input(OLPC_GPIO_DCON_STAT1); + gpio_direction_input(OLPC_GPIO_DCON_IRQ); + gpio_direction_input(OLPC_GPIO_DCON_BLANK); + gpio_direction_output(OLPC_GPIO_DCON_LOAD, + dcon->curr_src == DCON_SOURCE_CPU); + + /* Set up the interrupt mappings */ + + /* Set the IRQ to pair 2 */ + cs5535_gpio_setup_event(OLPC_GPIO_DCON_IRQ, 2, 0); + + /* Enable group 2 to trigger the DCON interrupt */ + cs5535_gpio_set_irq(2, DCON_IRQ); + + /* Select edge level for interrupt (in PIC) */ + lob = inb(0x4d0); + lob &= ~(1 << DCON_IRQ); + outb(lob, 0x4d0); + + /* Register the interrupt handler */ + if (request_irq(DCON_IRQ, &dcon_interrupt, 0, "DCON", dcon)) { + pr_err("failed to request DCON's irq\n"); + goto err_req_irq; + } + + /* Clear INV_EN for GPIO7 (DCONIRQ) */ + cs5535_gpio_clear(OLPC_GPIO_DCON_IRQ, GPIO_INPUT_INVERT); + + /* Enable filter for GPIO12 (DCONBLANK) */ + cs5535_gpio_set(OLPC_GPIO_DCON_BLANK, GPIO_INPUT_FILTER); + + /* Disable filter for GPIO7 */ + cs5535_gpio_clear(OLPC_GPIO_DCON_IRQ, GPIO_INPUT_FILTER); + + /* Disable event counter for GPIO7 (DCONIRQ) and GPIO12 (DCONBLANK) */ + cs5535_gpio_clear(OLPC_GPIO_DCON_IRQ, GPIO_INPUT_EVENT_COUNT); + cs5535_gpio_clear(OLPC_GPIO_DCON_BLANK, GPIO_INPUT_EVENT_COUNT); + + /* Add GPIO12 to the Filter Event Pair #7 */ + cs5535_gpio_set(OLPC_GPIO_DCON_BLANK, GPIO_FE7_SEL); + + /* Turn off negative Edge Enable for GPIO12 */ + cs5535_gpio_clear(OLPC_GPIO_DCON_BLANK, GPIO_NEGATIVE_EDGE_EN); + + /* Enable negative Edge Enable for GPIO7 */ + cs5535_gpio_set(OLPC_GPIO_DCON_IRQ, GPIO_NEGATIVE_EDGE_EN); + + /* Zero the filter amount for Filter Event Pair #7 */ + cs5535_gpio_set(0, GPIO_FLTR7_AMOUNT); + + /* Clear the negative edge status for GPIO7 and GPIO12 */ + cs5535_gpio_set(OLPC_GPIO_DCON_IRQ, GPIO_NEGATIVE_EDGE_STS); + cs5535_gpio_set(OLPC_GPIO_DCON_BLANK, GPIO_NEGATIVE_EDGE_STS); + + /* FIXME: Clear the positive status as well, just to be sure */ + cs5535_gpio_set(OLPC_GPIO_DCON_IRQ, GPIO_POSITIVE_EDGE_STS); + cs5535_gpio_set(OLPC_GPIO_DCON_BLANK, GPIO_POSITIVE_EDGE_STS); + + /* Enable events for GPIO7 (DCONIRQ) and GPIO12 (DCONBLANK) */ + cs5535_gpio_set(OLPC_GPIO_DCON_IRQ, GPIO_EVENTS_ENABLE); + cs5535_gpio_set(OLPC_GPIO_DCON_BLANK, GPIO_EVENTS_ENABLE); + + return 0; + +err_req_irq: + gpio_free(OLPC_GPIO_DCON_BLANK); +err_gp_blank: + gpio_free(OLPC_GPIO_DCON_LOAD); +err_gp_load: + gpio_free(OLPC_GPIO_DCON_IRQ); +err_gp_irq: + gpio_free(OLPC_GPIO_DCON_STAT1); +err_gp_stat1: + gpio_free(OLPC_GPIO_DCON_STAT0); + return -EIO; +} + +static void dcon_wiggle_xo_1(void) +{ + int x; + + /* + * According to HiMax, when powering the DCON up we should hold + * SMB_DATA high for 8 SMB_CLK cycles. This will force the DCON + * state machine to reset to a (sane) initial state. Mitch Bradley + * did some testing and discovered that holding for 16 SMB_CLK cycles + * worked a lot more reliably, so that's what we do here. + * + * According to the cs5536 spec, to set GPIO14 to SMB_CLK we must + * simultaneously set AUX1 IN/OUT to GPIO14; ditto for SMB_DATA and + * GPIO15. + */ + cs5535_gpio_set(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_VAL); + cs5535_gpio_set(OLPC_GPIO_SMB_DATA, GPIO_OUTPUT_VAL); + cs5535_gpio_set(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_ENABLE); + cs5535_gpio_set(OLPC_GPIO_SMB_DATA, GPIO_OUTPUT_ENABLE); + cs5535_gpio_clear(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_AUX1); + cs5535_gpio_clear(OLPC_GPIO_SMB_DATA, GPIO_OUTPUT_AUX1); + cs5535_gpio_clear(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_AUX2); + cs5535_gpio_clear(OLPC_GPIO_SMB_DATA, GPIO_OUTPUT_AUX2); + cs5535_gpio_clear(OLPC_GPIO_SMB_CLK, GPIO_INPUT_AUX1); + cs5535_gpio_clear(OLPC_GPIO_SMB_DATA, GPIO_INPUT_AUX1); + + for (x = 0; x < 16; x++) { + udelay(5); + cs5535_gpio_clear(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_VAL); + udelay(5); + cs5535_gpio_set(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_VAL); + } + udelay(5); + cs5535_gpio_set(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_AUX1); + cs5535_gpio_set(OLPC_GPIO_SMB_DATA, GPIO_OUTPUT_AUX1); + cs5535_gpio_set(OLPC_GPIO_SMB_CLK, GPIO_INPUT_AUX1); + cs5535_gpio_set(OLPC_GPIO_SMB_DATA, GPIO_INPUT_AUX1); +} + +static void dcon_set_dconload_1(int val) +{ + gpio_set_value(OLPC_GPIO_DCON_LOAD, val); +} + +static int dcon_read_status_xo_1(u8 *status) +{ + *status = gpio_get_value(OLPC_GPIO_DCON_STAT0); + *status |= gpio_get_value(OLPC_GPIO_DCON_STAT1) << 1; + + /* Clear the negative edge status for GPIO7 */ + cs5535_gpio_set(OLPC_GPIO_DCON_IRQ, GPIO_NEGATIVE_EDGE_STS); + + return 0; +} + +struct dcon_platform_data dcon_pdata_xo_1 = { + .init = dcon_init_xo_1, + .bus_stabilize_wiggle = dcon_wiggle_xo_1, + .set_dconload = dcon_set_dconload_1, + .read_status = dcon_read_status_xo_1, +}; |