diff options
Diffstat (limited to 'arch/arm/mach-lh7a40x/ssp-cpld.c')
| -rw-r--r-- | arch/arm/mach-lh7a40x/ssp-cpld.c | 343 |
1 files changed, 0 insertions, 343 deletions
diff --git a/arch/arm/mach-lh7a40x/ssp-cpld.c b/arch/arm/mach-lh7a40x/ssp-cpld.c deleted file mode 100644 index 2901d49d148..00000000000 --- a/arch/arm/mach-lh7a40x/ssp-cpld.c +++ /dev/null @@ -1,343 +0,0 @@ -/* arch/arm/mach-lh7a40x/ssp-cpld.c - * - * Copyright (C) 2004,2005 Marc Singer - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * version 2 as published by the Free Software Foundation. - * - * SSP/SPI driver for the CardEngine CPLD. - * - */ - -/* NOTES - ----- - - o *** This driver is cribbed from the 7952x implementation. - Some comments may not apply. - - o This driver contains sufficient logic to control either the - serial EEPROMs or the audio codec. It is included in the kernel - to support the codec. The EEPROMs are really the responsibility - of the boot loader and should probably be left alone. - - o The code must be augmented to cope with multiple, simultaneous - clients. - o The audio codec writes to the codec chip whenever playback - starts. - o The touchscreen driver writes to the ads chip every time it - samples. - o The audio codec must write 16 bits, but the touch chip writes - are 8 bits long. - o We need to be able to keep these configurations separate while - simultaneously active. - - */ - -#include <linux/module.h> -#include <linux/kernel.h> -//#include <linux/sched.h> -#include <linux/errno.h> -#include <linux/interrupt.h> -//#include <linux/ioport.h> -#include <linux/init.h> -#include <linux/delay.h> -#include <linux/spinlock.h> -#include <linux/io.h> - -#include <asm/irq.h> -#include <mach/hardware.h> - -#include <mach/ssp.h> - -//#define TALK - -#if defined (TALK) -#define PRINTK(f...) printk (f) -#else -#define PRINTK(f...) do {} while (0) -#endif - -#if defined (CONFIG_ARCH_LH7A400) -# define CPLD_SPID __REGP16(CPLD06_VIRT) /* SPI data */ -# define CPLD_SPIC __REGP16(CPLD08_VIRT) /* SPI control */ -# define CPLD_SPIC_CS_CODEC (1<<0) -# define CPLD_SPIC_CS_TOUCH (1<<1) -# define CPLD_SPIC_WRITE (0<<2) -# define CPLD_SPIC_READ (1<<2) -# define CPLD_SPIC_DONE (1<<3) /* r/o */ -# define CPLD_SPIC_LOAD (1<<4) -# define CPLD_SPIC_START (1<<4) -# define CPLD_SPIC_LOADED (1<<5) /* r/o */ -#endif - -#define CPLD_SPI __REGP16(CPLD0A_VIRT) /* SPI operation */ -#define CPLD_SPI_CS_EEPROM (1<<3) -#define CPLD_SPI_SCLK (1<<2) -#define CPLD_SPI_TX_SHIFT (1) -#define CPLD_SPI_TX (1<<CPLD_SPI_TX_SHIFT) -#define CPLD_SPI_RX_SHIFT (0) -#define CPLD_SPI_RX (1<<CPLD_SPI_RX_SHIFT) - -/* *** FIXME: these timing values are substantially larger than the - *** chip requires. We may implement an nsleep () function. */ -#define T_SKH 1 /* Clock time high (us) */ -#define T_SKL 1 /* Clock time low (us) */ -#define T_CS 1 /* Minimum chip select low time (us) */ -#define T_CSS 1 /* Minimum chip select setup time (us) */ -#define T_DIS 1 /* Data setup time (us) */ - - /* EEPROM SPI bits */ -#define P_START (1<<9) -#define P_WRITE (1<<7) -#define P_READ (2<<7) -#define P_ERASE (3<<7) -#define P_EWDS (0<<7) -#define P_WRAL (0<<7) -#define P_ERAL (0<<7) -#define P_EWEN (0<<7) -#define P_A_EWDS (0<<5) -#define P_A_WRAL (1<<5) -#define P_A_ERAL (2<<5) -#define P_A_EWEN (3<<5) - -struct ssp_configuration { - int device; - int mode; - int speed; - int frame_size_write; - int frame_size_read; -}; - -static struct ssp_configuration ssp_configuration; -static spinlock_t ssp_lock; - -static void enable_cs (void) -{ - switch (ssp_configuration.device) { - case DEVICE_EEPROM: - CPLD_SPI |= CPLD_SPI_CS_EEPROM; - break; - } - udelay (T_CSS); -} - -static void disable_cs (void) -{ - switch (ssp_configuration.device) { - case DEVICE_EEPROM: - CPLD_SPI &= ~CPLD_SPI_CS_EEPROM; - break; - } - udelay (T_CS); -} - -static void pulse_clock (void) -{ - CPLD_SPI |= CPLD_SPI_SCLK; - udelay (T_SKH); - CPLD_SPI &= ~CPLD_SPI_SCLK; - udelay (T_SKL); -} - - -/* execute_spi_command - - sends an spi command to a device. It first sends cwrite bits from - v. If cread is greater than zero it will read cread bits - (discarding the leading 0 bit) and return them. If cread is less - than zero it will check for completetion status and return 0 on - success or -1 on timeout. If cread is zero it does nothing other - than sending the command. - - On the LPD7A400, we can only read or write multiples of 8 bits on - the codec and the touch screen device. Here, we round up. - -*/ - -static int execute_spi_command (int v, int cwrite, int cread) -{ - unsigned long l = 0; - -#if defined (CONFIG_MACH_LPD7A400) - /* The codec and touch devices cannot be bit-banged. Instead, - * the CPLD provides an eight-bit shift register and a crude - * interface. */ - if ( ssp_configuration.device == DEVICE_CODEC - || ssp_configuration.device == DEVICE_TOUCH) { - int select = 0; - - PRINTK ("spi(%d %d.%d) 0x%04x", - ssp_configuration.device, cwrite, cread, - v); -#if defined (TALK) - if (ssp_configuration.device == DEVICE_CODEC) - PRINTK (" 0x%03x -> %2d", v & 0x1ff, (v >> 9) & 0x7f); -#endif - PRINTK ("\n"); - - if (ssp_configuration.device == DEVICE_CODEC) - select = CPLD_SPIC_CS_CODEC; - if (ssp_configuration.device == DEVICE_TOUCH) - select = CPLD_SPIC_CS_TOUCH; - if (cwrite) { - for (cwrite = (cwrite + 7)/8; cwrite-- > 0; ) { - CPLD_SPID = (v >> (8*cwrite)) & 0xff; - CPLD_SPIC = select | CPLD_SPIC_LOAD; - while (!(CPLD_SPIC & CPLD_SPIC_LOADED)) - ; - CPLD_SPIC = select; - while (!(CPLD_SPIC & CPLD_SPIC_DONE)) - ; - } - v = 0; - } - if (cread) { - mdelay (2); /* *** FIXME: required by ads7843? */ - v = 0; - for (cread = (cread + 7)/8; cread-- > 0;) { - CPLD_SPID = 0; - CPLD_SPIC = select | CPLD_SPIC_READ - | CPLD_SPIC_START; - while (!(CPLD_SPIC & CPLD_SPIC_LOADED)) - ; - CPLD_SPIC = select | CPLD_SPIC_READ; - while (!(CPLD_SPIC & CPLD_SPIC_DONE)) - ; - v = (v << 8) | CPLD_SPID; - } - } - return v; - } -#endif - - PRINTK ("spi(%d) 0x%04x -> 0x%x\r\n", ssp_configuration.device, - v & 0x1ff, (v >> 9) & 0x7f); - - enable_cs (); - - v <<= CPLD_SPI_TX_SHIFT; /* Correction for position of SPI_TX bit */ - while (cwrite--) { - CPLD_SPI - = (CPLD_SPI & ~CPLD_SPI_TX) - | ((v >> cwrite) & CPLD_SPI_TX); - udelay (T_DIS); - pulse_clock (); - } - - if (cread < 0) { - int delay = 10; - disable_cs (); - udelay (1); - enable_cs (); - - l = -1; - do { - if (CPLD_SPI & CPLD_SPI_RX) { - l = 0; - break; - } - } while (udelay (1), --delay); - } - else - /* We pulse the clock before the data to skip the leading zero. */ - while (cread-- > 0) { - pulse_clock (); - l = (l<<1) - | (((CPLD_SPI & CPLD_SPI_RX) - >> CPLD_SPI_RX_SHIFT) & 0x1); - } - - disable_cs (); - return l; -} - -static int ssp_init (void) -{ - spin_lock_init (&ssp_lock); - memset (&ssp_configuration, 0, sizeof (ssp_configuration)); - return 0; -} - - -/* ssp_chip_select - - drops the chip select line for the CPLD shift-register controlled - devices. It doesn't enable chip - -*/ - -static void ssp_chip_select (int enable) -{ -#if defined (CONFIG_MACH_LPD7A400) - int select; - - if (ssp_configuration.device == DEVICE_CODEC) - select = CPLD_SPIC_CS_CODEC; - else if (ssp_configuration.device == DEVICE_TOUCH) - select = CPLD_SPIC_CS_TOUCH; - else - return; - - if (enable) - CPLD_SPIC = select; - else - CPLD_SPIC = 0; -#endif -} - -static void ssp_acquire (void) -{ - spin_lock (&ssp_lock); -} - -static void ssp_release (void) -{ - ssp_chip_select (0); /* just in case */ - spin_unlock (&ssp_lock); -} - -static int ssp_configure (int device, int mode, int speed, - int frame_size_write, int frame_size_read) -{ - ssp_configuration.device = device; - ssp_configuration.mode = mode; - ssp_configuration.speed = speed; - ssp_configuration.frame_size_write = frame_size_write; - ssp_configuration.frame_size_read = frame_size_read; - - return 0; -} - -static int ssp_read (void) -{ - return execute_spi_command (0, 0, ssp_configuration.frame_size_read); -} - -static int ssp_write (u16 data) -{ - execute_spi_command (data, ssp_configuration.frame_size_write, 0); - return 0; -} - -static int ssp_write_read (u16 data) -{ - return execute_spi_command (data, ssp_configuration.frame_size_write, - ssp_configuration.frame_size_read); -} - -struct ssp_driver lh7a40x_cpld_ssp_driver = { - .init = ssp_init, - .acquire = ssp_acquire, - .release = ssp_release, - .configure = ssp_configure, - .chip_select = ssp_chip_select, - .read = ssp_read, - .write = ssp_write, - .write_read = ssp_write_read, -}; - - -MODULE_AUTHOR("Marc Singer"); -MODULE_DESCRIPTION("LPD7A40X CPLD SPI driver"); -MODULE_LICENSE("GPL"); |