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Diffstat (limited to 'board/spear/x600/fpga.c')
| -rw-r--r-- | board/spear/x600/fpga.c | 280 |
1 files changed, 280 insertions, 0 deletions
diff --git a/board/spear/x600/fpga.c b/board/spear/x600/fpga.c new file mode 100644 index 0000000..85eb31b --- /dev/null +++ b/board/spear/x600/fpga.c @@ -0,0 +1,280 @@ +/* + * Copyright (C) 2012 Stefan Roese <sr@denx.de> + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#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; +} |