/*
* Copyright © 2013 Eugeniy Meshcheryakov <eugen@debian.org>
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*/
#include <bsp.h>
#include <bspopts.h>
#include <bsp/ssi.h>
#include <bsp/syscon.h>
#include <bsp/io.h>
#include <bsp/lm3s69xx.h>
typedef struct {
rtems_libi2c_bus_t bus;
volatile lm3s69xx_ssi *regs;
int bus_number;
uint16_t idle_char;
uint8_t cs_pin;
lm3s69xx_gpio_config io_configs[3];
} lm3s69xx_ssi_bus_entry;
static rtems_status_code lm3s69xx_ssi_init(rtems_libi2c_bus_t *bus)
{
lm3s69xx_ssi_bus_entry *e = (lm3s69xx_ssi_bus_entry *)bus;
volatile lm3s69xx_ssi* regs = e->regs;
uint32_t clock_div = LM3S69XX_SYSTEM_CLOCK / 2 / LM3S69XX_SSI_CLOCK;
lm3s69xx_gpio_set_config_array(e->io_configs, 3);
lm3s69xx_syscon_enable_ssi_clock(e->bus_number, true);
regs->cr1 = 0;
regs->cpsr = SSI_CPSRDIV(2);
regs->cr0 = SSICR0_SCR(clock_div - 1) | SSICR0_SPO | SSICR0_SPH | SSICR0_FRF(0) | SSICR0_DSS(7);
regs->cr1 = SSICR1_SSE;
return RTEMS_SUCCESSFUL;
}
static rtems_status_code lm3s69xx_ssi_send_start(rtems_libi2c_bus_t *bus)
{
return RTEMS_SUCCESSFUL;
}
static rtems_status_code lm3s69xx_ssi_send_stop(rtems_libi2c_bus_t *bus)
{
lm3s69xx_ssi_bus_entry *e = (lm3s69xx_ssi_bus_entry *)bus;
volatile lm3s69xx_ssi* regs = e->regs;
while ((regs->sr & SSISR_BSY) != 0)
/* wait */;
lm3s69xx_gpio_set_pin(e->cs_pin, true);
return RTEMS_SUCCESSFUL;
}
static rtems_status_code lm3s69xx_ssi_send_addr(rtems_libi2c_bus_t *bus,
uint32_t addr, int rw)
{
lm3s69xx_ssi_bus_entry *e = (lm3s69xx_ssi_bus_entry *)bus;
e->cs_pin = addr;
lm3s69xx_gpio_set_pin(e->cs_pin, false);
return RTEMS_SUCCESSFUL;
}
static int lm3s69xx_ssi_read(rtems_libi2c_bus_t *bus, unsigned char *in, int n)
{
lm3s69xx_ssi_bus_entry *e = (lm3s69xx_ssi_bus_entry *)bus;
volatile lm3s69xx_ssi* regs = e->regs;
int i;
for (i = 0; i < n; i++) {
while ((regs->sr & SSISR_TNF) == 0)
/* wait */;
regs->dr = e->idle_char;
while ((regs->sr & SSISR_RNE) == 0)
/* wait */;
in[i] = regs->dr & 0xff;
}
return n;
}
static int lm3s69xx_ssi_write(rtems_libi2c_bus_t *bus, unsigned char *out, int n)
{
lm3s69xx_ssi_bus_entry *e = (lm3s69xx_ssi_bus_entry *)bus;
volatile lm3s69xx_ssi* regs = e->regs;
int i;
for (i = 0; i < n; i++) {
while ((regs->sr & SSISR_TNF) == 0)
/* wait */;
regs->dr = out[i];
while ((regs->sr & SSISR_RNE) == 0)
/* wait */;
uint32_t dummy = regs->dr;
(void)dummy;
}
return n;
}
static int lm3s69xx_ssi_ioctl(rtems_libi2c_bus_t *bus, int cmd, void *arg)
{
return -RTEMS_NOT_DEFINED;
}
static const rtems_libi2c_bus_ops_t lm3s69xx_ssi_ops = {
.init = lm3s69xx_ssi_init,
.send_start = lm3s69xx_ssi_send_start,
.send_stop = lm3s69xx_ssi_send_stop,
.send_addr = lm3s69xx_ssi_send_addr,
.read_bytes = lm3s69xx_ssi_read,
.write_bytes = lm3s69xx_ssi_write,
.ioctl = lm3s69xx_ssi_ioctl
};
static lm3s69xx_ssi_bus_entry ssi_0_bus = {
.bus = {
.ops = &lm3s69xx_ssi_ops,
.size = sizeof(lm3s69xx_ssi_bus_entry)
},
.regs = (volatile lm3s69xx_ssi *)LM3S69XX_SSI_0_BASE,
.bus_number = 0,
.idle_char = 0xffff,
.io_configs = {
#if defined(LM3S69XX_MCU_LM3S3749) || defined(LM3S69XX_MCU_LM3S6965) || defined(LM3S69XX_MCU_LM4F120)
LM3S69XX_PIN_SSI_TX(LM3S69XX_PORT_A, 2), /* CLK */
LM3S69XX_PIN_SSI_TX(LM3S69XX_PORT_A, 5), /* TX */
LM3S69XX_PIN_SSI_RX(LM3S69XX_PORT_A, 4) /* RX */
#else
#error No GPIO pin definitions for SSI 0
#endif
}
};
rtems_libi2c_bus_t * const lm3s69xx_ssi_0 = &ssi_0_bus.bus;
#if LM3S69XX_NUM_SSI_BLOCKS > 1
static lm3s69xx_ssi_bus_entry ssi_1_bus = {
.bus = {
.ops = &lm3s69xx_ssi_ops,
.size = sizeof(lm3s69xx_ssi_bus_entry)
},
.regs = (volatile lm3s69xx_ssi *)LM3S69XX_SSI_1_BASE,
.bus_number = 1,
.idle_char = 0xffff,
.io_configs = {
#if defined(LM3S69XX_MCU_LM3S3749) || defined(LM3S69XX_MCU_LM4F120)
LM3S69XX_PIN_SSI_TX(LM3S69XX_PORT_E, 0), /* CLK */
LM3S69XX_PIN_SSI_TX(LM3S69XX_PORT_E, 3), /* TX */
LM3S69XX_PIN_SSI_RX(LM3S69XX_PORT_E, 2) /* RX */
#else
#error No GPIO pin definitions for SSI 1
#endif
}
};
rtems_libi2c_bus_t * const lm3s69xx_ssi_1 = &ssi_1_bus.bus;
#endif /* LM3S69XX_NUM_SSI_BLOCKS > 1 */