u-boot/board/spear/x600/fpga.c
Tom Rini 83d290c56f SPDX: Convert all of our single license tags to Linux Kernel style
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>
2018-05-07 09:34:12 -04:00

263 lines
5.8 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2012 Stefan Roese <sr@denx.de>
*/
#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;
}