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 | 171 |
1 files changed, 171 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 0000000..779fb7d --- /dev/null +++ b/drivers/staging/olpc_dcon/olpc_dcon_xo_1.c @@ -0,0 +1,171 @@ +/* + * 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. + */ + +#include <asm/olpc.h> + +#include "olpc_dcon.h" + +/* Base address of the GPIO registers */ +static unsigned long gpio_base; + +/* + * List of GPIOs that we care about: + * (in) GPIO12 -- DCONBLANK + * (in) GPIO[56] -- DCONSTAT[01] + * (out) GPIO11 -- DCONLOAD + */ + +#define IN_GPIOS ((1<<5) | (1<<6) | (1<<7) | (1<<12)) +#define OUT_GPIOS (1<<11) + +static int dcon_init_xo_1(void) +{ + unsigned long lo, hi; + unsigned char lob; + + rdmsr(MSR_LBAR_GPIO, lo, hi); + + /* Check the mask and whether GPIO is enabled (sanity check) */ + if (hi != 0x0000f001) { + printk(KERN_ERR "GPIO not enabled -- cannot use DCON\n"); + return -ENODEV; + } + + /* Mask off the IO base address */ + gpio_base = lo & 0x0000ff00; + + /* Turn off the event enable for GPIO7 just to be safe */ + outl(1 << (16+7), gpio_base + GPIOx_EVNT_EN); + + /* Set the directions for the GPIO pins */ + outl(OUT_GPIOS | (IN_GPIOS << 16), gpio_base + GPIOx_OUT_EN); + outl(IN_GPIOS | (OUT_GPIOS << 16), gpio_base + GPIOx_IN_EN); + + /* Set up the interrupt mappings */ + + /* Set the IRQ to pair 2 */ + geode_gpio_event_irq(OLPC_GPIO_DCON_IRQ, 2); + + /* Enable group 2 to trigger the DCON interrupt */ + geode_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 interupt handler */ + if (request_irq(DCON_IRQ, &dcon_interrupt, 0, "DCON", &dcon_driver)) + return -EIO; + + /* Clear INV_EN for GPIO7 (DCONIRQ) */ + outl((1<<(16+7)), gpio_base + GPIOx_INV_EN); + + /* Enable filter for GPIO12 (DCONBLANK) */ + outl(1<<(12), gpio_base + GPIOx_IN_FLTR_EN); + + /* Disable filter for GPIO7 */ + outl(1<<(16+7), gpio_base + GPIOx_IN_FLTR_EN); + + /* Disable event counter for GPIO7 (DCONIRQ) and GPIO12 (DCONBLANK) */ + + outl(1<<(16+7), gpio_base + GPIOx_EVNTCNT_EN); + outl(1<<(16+12), gpio_base + GPIOx_EVNTCNT_EN); + + /* Add GPIO12 to the Filter Event Pair #7 */ + outb(12, gpio_base + GPIO_FE7_SEL); + + /* Turn off negative Edge Enable for GPIO12 */ + outl(1<<(16+12), gpio_base + GPIOx_NEGEDGE_EN); + + /* Enable negative Edge Enable for GPIO7 */ + outl(1<<7, gpio_base + GPIOx_NEGEDGE_EN); + + /* Zero the filter amount for Filter Event Pair #7 */ + outw(0, gpio_base + GPIO_FLT7_AMNT); + + /* Clear the negative edge status for GPIO7 and GPIO12 */ + outl((1<<7) | (1<<12), gpio_base+0x4c); + + /* FIXME: Clear the posiitive status as well, just to be sure */ + outl((1<<7) | (1<<12), gpio_base+0x48); + + /* Enable events for GPIO7 (DCONIRQ) and GPIO12 (DCONBLANK) */ + outl((1<<(7))|(1<<12), gpio_base + GPIOx_EVNT_EN); + + /* Determine the current state by reading the GPIO bit */ + /* Earlier stages of the boot process have established the state */ + dcon_source = inl(gpio_base + GPIOx_OUT_VAL) & (1<<11) + ? DCON_SOURCE_CPU + : DCON_SOURCE_DCON; + dcon_pending = dcon_source; + + return 0; +} + +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. + */ + geode_gpio_set(OLPC_GPIO_SMB_CLK|OLPC_GPIO_SMB_DATA, GPIO_OUTPUT_VAL); + geode_gpio_set(OLPC_GPIO_SMB_CLK|OLPC_GPIO_SMB_DATA, GPIO_OUTPUT_ENABLE); + geode_gpio_clear(OLPC_GPIO_SMB_CLK|OLPC_GPIO_SMB_DATA, GPIO_OUTPUT_AUX1); + geode_gpio_clear(OLPC_GPIO_SMB_CLK|OLPC_GPIO_SMB_DATA, GPIO_OUTPUT_AUX2); + geode_gpio_clear(OLPC_GPIO_SMB_CLK|OLPC_GPIO_SMB_DATA, GPIO_INPUT_AUX1); + + for (x = 0; x < 16; x++) { + udelay(5); + geode_gpio_clear(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_VAL); + udelay(5); + geode_gpio_set(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_VAL); + } + udelay(5); + geode_gpio_set(OLPC_GPIO_SMB_CLK|OLPC_GPIO_SMB_DATA, GPIO_OUTPUT_AUX1); + geode_gpio_set(OLPC_GPIO_SMB_CLK|OLPC_GPIO_SMB_DATA, GPIO_INPUT_AUX1); +} + +static void dcon_set_dconload_1(int val) +{ + if (val) + outl(1<<11, gpio_base + GPIOx_OUT_VAL); + else + outl(1<<(11 + 16), gpio_base + GPIOx_OUT_VAL); +} + +static int dcon_read_status_xo_1(void) +{ + int status = inl(gpio_base + GPIOx_READ_BACK) >> 5; + + /* Clear the negative edge status for GPIO7 */ + outl(1 << 7, gpio_base + GPIOx_NEGEDGE_STS); + + return status; +} + +static 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, +}; |
