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/*
* Copyright (C) 2012 Stefan Roese <sr@denx.de>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <spartan3.h>
#include <command.h>
#include <asm/gpio.h>
#include <asm/io.h>
#include <asm/arch/hardware.h>
#include <asm/arch/spr_misc.h>
#include <asm/arch/spr_ssp.h>
/*
* FPGA program pin configuration on X600:
*
* Only PROG and DONE are connected to GPIOs. INIT is not connected to the
* SoC at all. And CLOCK and DATA are connected to the SSP2 port. We use
* 16bit serial writes via this SSP port to write the data bits into the
* FPGA.
*/
#define CONFIG_SYS_FPGA_PROG 2
#define CONFIG_SYS_FPGA_DONE 3
/*
* Set the active-low FPGA reset signal.
*/
static void fpga_reset(int assert)
{
/*
* On x600 we have no means to toggle the FPGA reset signal
*/
debug("%s:%d: RESET (%d)\n", __func__, __LINE__, assert);
}
/*
* Set the FPGA's active-low SelectMap program line to the specified level
*/
static int fpga_pgm_fn(int assert, int flush, int cookie)
{
debug("%s:%d: FPGA PROG (%d)\n", __func__, __LINE__, assert);
gpio_set_value(CONFIG_SYS_FPGA_PROG, assert);
return assert;
}
/*
* Test the state of the active-low FPGA INIT line. Return 1 on INIT
* asserted (low).
*/
static int fpga_init_fn(int cookie)
{
static int state;
debug("%s:%d: init (state=%d)\n", __func__, __LINE__, state);
/*
* On x600, the FPGA INIT signal is not connected to the SoC.
* We can't read the INIT status. Let's return the "correct"
* INIT signal state generated via a local state-machine.
*/
if (++state == 1) {
return 1;
} else {
state = 0;
return 0;
}
}
/*
* Test the state of the active-high FPGA DONE pin
*/
static int fpga_done_fn(int cookie)
{
struct ssp_regs *ssp = (struct ssp_regs *)CONFIG_SSP2_BASE;
/*
* Wait for Tx-FIFO to become empty before looking for DONE
*/
while (!(readl(&ssp->sspsr) & SSPSR_TFE))
;
if (gpio_get_value(CONFIG_SYS_FPGA_DONE))
return 1;
else
return 0;
}
/*
* FPGA pre-configuration function. Just make sure that
* FPGA reset is asserted to keep the FPGA from starting up after
* configuration.
*/
static int fpga_pre_config_fn(int cookie)
{
debug("%s:%d: FPGA pre-configuration\n", __func__, __LINE__);
fpga_reset(true);
return 0;
}
/*
* FPGA post configuration function. Blip the FPGA reset line and then see if
* the FPGA appears to be running.
*/
static int fpga_post_config_fn(int cookie)
{
int rc = 0;
debug("%s:%d: FPGA post configuration\n", __func__, __LINE__);
fpga_reset(true);
udelay(100);
fpga_reset(false);
udelay(100);
return rc;
}
static int fpga_clk_fn(int assert_clk, int flush, int cookie)
{
/*
* No dedicated clock signal on x600 (data & clock generated)
* in SSP interface. So we don't have to do anything here.
*/
return assert_clk;
}
static int fpga_wr_fn(int assert_write, int flush, int cookie)
{
struct ssp_regs *ssp = (struct ssp_regs *)CONFIG_SSP2_BASE;
static int count;
static u16 data;
/*
* First collect 16 bits of data
*/
data = data << 1;
if (assert_write)
data |= 1;
/*
* If 16 bits are not available, return for more bits
*/
count++;
if (count != 16)
return assert_write;
count = 0;
/*
* Wait for Tx-FIFO to become ready
*/
while (!(readl(&ssp->sspsr) & SSPSR_TNF))
;
/* Send 16 bits to FPGA via SSP bus */
writel(data, &ssp->sspdr);
return assert_write;
}
static xilinx_spartan3_slave_serial_fns x600_fpga_fns = {
fpga_pre_config_fn,
fpga_pgm_fn,
fpga_clk_fn,
fpga_init_fn,
fpga_done_fn,
fpga_wr_fn,
fpga_post_config_fn,
};
static Xilinx_desc fpga[CONFIG_FPGA_COUNT] = {
XILINX_XC3S1200E_DESC(slave_serial, &x600_fpga_fns, 0)
};
/*
* Initialize the SelectMap interface. We assume that the mode and the
* initial state of all of the port pins have already been set!
*/
static void fpga_serialslave_init(void)
{
debug("%s:%d: Initialize serial slave interface\n", __func__, __LINE__);
fpga_pgm_fn(false, false, 0); /* make sure program pin is inactive */
}
static int expi_setup(int freq)
{
struct misc_regs *misc = (struct misc_regs *)CONFIG_SPEAR_MISCBASE;
int pll2_m, pll2_n, pll2_p, expi_x, expi_y;
pll2_m = (freq * 2) / 1000;
pll2_n = 15;
pll2_p = 1;
expi_x = 1;
expi_y = 2;
/*
* Disable reset, Low compression, Disable retiming, Enable Expi,
* Enable soft reset, DMA, PLL2, Internal
*/
writel(EXPI_CLK_CFG_LOW_COMPR | EXPI_CLK_CFG_CLK_EN | EXPI_CLK_CFG_RST |
EXPI_CLK_SYNT_EN | EXPI_CLK_CFG_SEL_PLL2 |
EXPI_CLK_CFG_INT_CLK_EN | (expi_y << 16) | (expi_x << 24),
&misc->expi_clk_cfg);
/*
* 6 uA, Internal feedback, 1st order, Non-dithered, Sample Parameters,
* Enable PLL2, Disable reset
*/
writel((pll2_m << 24) | (pll2_p << 8) | (pll2_n), &misc->pll2_frq);
writel(PLL2_CNTL_6UA | PLL2_CNTL_SAMPLE | PLL2_CNTL_ENABLE |
PLL2_CNTL_RESETN | PLL2_CNTL_LOCK, &misc->pll2_cntl);
/*
* Disable soft reset
*/
clrbits_le32(&misc->expi_clk_cfg, EXPI_CLK_CFG_RST);
return 0;
}
/*
* Initialize the fpga
*/
int x600_init_fpga(void)
{
struct ssp_regs *ssp = (struct ssp_regs *)CONFIG_SSP2_BASE;
struct misc_regs *misc = (struct misc_regs *)CONFIG_SPEAR_MISCBASE;
/* Enable SSP2 clock */
writel(readl(&misc->periph1_clken) | MISC_SSP2ENB | MISC_GPIO4ENB,
&misc->periph1_clken);
/* Set EXPI clock to 45 MHz */
expi_setup(45000);
/* Configure GPIO directions */
gpio_direction_output(CONFIG_SYS_FPGA_PROG, 0);
gpio_direction_input(CONFIG_SYS_FPGA_DONE);
writel(SSPCR0_DSS_16BITS, &ssp->sspcr0);
writel(SSPCR1_SSE, &ssp->sspcr1);
/*
* Set lowest prescale divisor value (CPSDVSR) of 2 for max download
* speed.
*
* Actual data clock rate is: 80MHz / (CPSDVSR * (SCR + 1))
* With CPSDVSR at 2 and SCR at 0, the maximume clock rate is 40MHz.
*/
writel(2, &ssp->sspcpsr);
fpga_init();
fpga_serialslave_init();
debug("%s:%d: Adding fpga 0\n", __func__, __LINE__);
fpga_add(fpga_xilinx, &fpga[0]);
return 0;
}
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