202 lines
6.4 KiB
C
202 lines
6.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Mainly by David Woodhouse, somewhat modified by Jordan Crouse
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*
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* Copyright © 2006-2007 Red Hat, Inc.
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* Copyright © 2006-2007 Advanced Micro Devices, Inc.
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* Copyright © 2009 VIA Technology, Inc.
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* Copyright (c) 2010 Andres Salomon <dilinger@queued.net>
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/cs5535.h>
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#include <linux/gpio/consumer.h>
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#include <linux/delay.h>
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#include <linux/i2c.h>
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#include <asm/olpc.h>
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#include "olpc_dcon.h"
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enum dcon_gpios {
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OLPC_DCON_STAT0,
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OLPC_DCON_STAT1,
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OLPC_DCON_IRQ,
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OLPC_DCON_LOAD,
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OLPC_DCON_BLANK,
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};
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static const struct dcon_gpio gpios_asis[] = {
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[OLPC_DCON_STAT0] = { .name = "dcon_stat0", .flags = GPIOD_ASIS },
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[OLPC_DCON_STAT1] = { .name = "dcon_stat1", .flags = GPIOD_ASIS },
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[OLPC_DCON_IRQ] = { .name = "dcon_irq", .flags = GPIOD_ASIS },
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[OLPC_DCON_LOAD] = { .name = "dcon_load", .flags = GPIOD_ASIS },
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[OLPC_DCON_BLANK] = { .name = "dcon_blank", .flags = GPIOD_ASIS },
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};
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static struct gpio_desc *gpios[5];
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static int dcon_init_xo_1(struct dcon_priv *dcon)
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{
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unsigned char lob;
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int ret, i;
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const struct dcon_gpio *pin = &gpios_asis[0];
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for (i = 0; i < ARRAY_SIZE(gpios_asis); i++) {
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gpios[i] = devm_gpiod_get(&dcon->client->dev, pin[i].name,
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pin[i].flags);
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if (IS_ERR(gpios[i])) {
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ret = PTR_ERR(gpios[i]);
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pr_err("failed to request %s GPIO: %d\n", pin[i].name,
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ret);
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return ret;
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}
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}
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/* Turn off the event enable for GPIO7 just to be safe */
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cs5535_gpio_clear(OLPC_GPIO_DCON_IRQ, GPIO_EVENTS_ENABLE);
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/*
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* Determine the current state by reading the GPIO bit; earlier
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* stages of the boot process have established the state.
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*
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* Note that we read GPIO_OUTPUT_VAL rather than GPIO_READ_BACK here;
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* this is because OFW will disable input for the pin and set a value..
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* READ_BACK will only contain a valid value if input is enabled and
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* then a value is set. So, future readings of the pin can use
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* READ_BACK, but the first one cannot. Awesome, huh?
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*/
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dcon->curr_src = cs5535_gpio_isset(OLPC_GPIO_DCON_LOAD, GPIO_OUTPUT_VAL)
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? DCON_SOURCE_CPU
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: DCON_SOURCE_DCON;
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dcon->pending_src = dcon->curr_src;
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/* Set the directions for the GPIO pins */
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gpiod_direction_input(gpios[OLPC_DCON_STAT0]);
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gpiod_direction_input(gpios[OLPC_DCON_STAT1]);
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gpiod_direction_input(gpios[OLPC_DCON_IRQ]);
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gpiod_direction_input(gpios[OLPC_DCON_BLANK]);
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gpiod_direction_output(gpios[OLPC_DCON_LOAD],
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dcon->curr_src == DCON_SOURCE_CPU);
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/* Set up the interrupt mappings */
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/* Set the IRQ to pair 2 */
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cs5535_gpio_setup_event(OLPC_GPIO_DCON_IRQ, 2, 0);
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/* Enable group 2 to trigger the DCON interrupt */
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cs5535_gpio_set_irq(2, DCON_IRQ);
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/* Select edge level for interrupt (in PIC) */
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lob = inb(0x4d0);
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lob &= ~(1 << DCON_IRQ);
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outb(lob, 0x4d0);
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/* Register the interrupt handler */
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if (request_irq(DCON_IRQ, &dcon_interrupt, 0, "DCON", dcon)) {
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pr_err("failed to request DCON's irq\n");
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return -EIO;
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}
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/* Clear INV_EN for GPIO7 (DCONIRQ) */
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cs5535_gpio_clear(OLPC_GPIO_DCON_IRQ, GPIO_INPUT_INVERT);
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/* Enable filter for GPIO12 (DCONBLANK) */
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cs5535_gpio_set(OLPC_GPIO_DCON_BLANK, GPIO_INPUT_FILTER);
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/* Disable filter for GPIO7 */
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cs5535_gpio_clear(OLPC_GPIO_DCON_IRQ, GPIO_INPUT_FILTER);
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/* Disable event counter for GPIO7 (DCONIRQ) and GPIO12 (DCONBLANK) */
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cs5535_gpio_clear(OLPC_GPIO_DCON_IRQ, GPIO_INPUT_EVENT_COUNT);
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cs5535_gpio_clear(OLPC_GPIO_DCON_BLANK, GPIO_INPUT_EVENT_COUNT);
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/* Add GPIO12 to the Filter Event Pair #7 */
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cs5535_gpio_set(OLPC_GPIO_DCON_BLANK, GPIO_FE7_SEL);
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/* Turn off negative Edge Enable for GPIO12 */
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cs5535_gpio_clear(OLPC_GPIO_DCON_BLANK, GPIO_NEGATIVE_EDGE_EN);
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/* Enable negative Edge Enable for GPIO7 */
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cs5535_gpio_set(OLPC_GPIO_DCON_IRQ, GPIO_NEGATIVE_EDGE_EN);
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/* Zero the filter amount for Filter Event Pair #7 */
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cs5535_gpio_set(0, GPIO_FLTR7_AMOUNT);
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/* Clear the negative edge status for GPIO7 and GPIO12 */
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cs5535_gpio_set(OLPC_GPIO_DCON_IRQ, GPIO_NEGATIVE_EDGE_STS);
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cs5535_gpio_set(OLPC_GPIO_DCON_BLANK, GPIO_NEGATIVE_EDGE_STS);
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/* FIXME: Clear the positive status as well, just to be sure */
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cs5535_gpio_set(OLPC_GPIO_DCON_IRQ, GPIO_POSITIVE_EDGE_STS);
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cs5535_gpio_set(OLPC_GPIO_DCON_BLANK, GPIO_POSITIVE_EDGE_STS);
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/* Enable events for GPIO7 (DCONIRQ) and GPIO12 (DCONBLANK) */
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cs5535_gpio_set(OLPC_GPIO_DCON_IRQ, GPIO_EVENTS_ENABLE);
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cs5535_gpio_set(OLPC_GPIO_DCON_BLANK, GPIO_EVENTS_ENABLE);
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return 0;
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}
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static void dcon_wiggle_xo_1(void)
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{
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int x;
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/*
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* According to HiMax, when powering the DCON up we should hold
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* SMB_DATA high for 8 SMB_CLK cycles. This will force the DCON
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* state machine to reset to a (sane) initial state. Mitch Bradley
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* did some testing and discovered that holding for 16 SMB_CLK cycles
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* worked a lot more reliably, so that's what we do here.
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*
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* According to the cs5536 spec, to set GPIO14 to SMB_CLK we must
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* simultaneously set AUX1 IN/OUT to GPIO14; ditto for SMB_DATA and
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* GPIO15.
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*/
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cs5535_gpio_set(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_VAL);
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cs5535_gpio_set(OLPC_GPIO_SMB_DATA, GPIO_OUTPUT_VAL);
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cs5535_gpio_set(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_ENABLE);
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cs5535_gpio_set(OLPC_GPIO_SMB_DATA, GPIO_OUTPUT_ENABLE);
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cs5535_gpio_clear(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_AUX1);
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cs5535_gpio_clear(OLPC_GPIO_SMB_DATA, GPIO_OUTPUT_AUX1);
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cs5535_gpio_clear(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_AUX2);
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cs5535_gpio_clear(OLPC_GPIO_SMB_DATA, GPIO_OUTPUT_AUX2);
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cs5535_gpio_clear(OLPC_GPIO_SMB_CLK, GPIO_INPUT_AUX1);
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cs5535_gpio_clear(OLPC_GPIO_SMB_DATA, GPIO_INPUT_AUX1);
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for (x = 0; x < 16; x++) {
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udelay(5);
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cs5535_gpio_clear(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_VAL);
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udelay(5);
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cs5535_gpio_set(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_VAL);
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}
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udelay(5);
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cs5535_gpio_set(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_AUX1);
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cs5535_gpio_set(OLPC_GPIO_SMB_DATA, GPIO_OUTPUT_AUX1);
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cs5535_gpio_set(OLPC_GPIO_SMB_CLK, GPIO_INPUT_AUX1);
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cs5535_gpio_set(OLPC_GPIO_SMB_DATA, GPIO_INPUT_AUX1);
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}
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static void dcon_set_dconload_1(int val)
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{
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gpiod_set_value(gpios[OLPC_DCON_LOAD], val);
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}
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static int dcon_read_status_xo_1(u8 *status)
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{
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*status = gpiod_get_value(gpios[OLPC_DCON_STAT0]);
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*status |= gpiod_get_value(gpios[OLPC_DCON_STAT1]) << 1;
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/* Clear the negative edge status for GPIO7 */
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cs5535_gpio_set(OLPC_GPIO_DCON_IRQ, GPIO_NEGATIVE_EDGE_STS);
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return 0;
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}
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struct dcon_platform_data dcon_pdata_xo_1 = {
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.init = dcon_init_xo_1,
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.bus_stabilize_wiggle = dcon_wiggle_xo_1,
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.set_dconload = dcon_set_dconload_1,
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.read_status = dcon_read_status_xo_1,
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};
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