+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0+
-/*
- * LPC32xx SSP interface (SPI mode)
- *
- * (C) Copyright 2014 DENX Software Engineering GmbH
- * Written-by: Albert ARIBAUD <albert.aribaud@3adev.fr>
- */
-
-#include <common.h>
-#include <linux/compat.h>
-#include <asm/io.h>
-#include <malloc.h>
-#include <spi.h>
-#include <asm/arch/clk.h>
-
-/* SSP chip registers */
-struct ssp_regs {
- u32 cr0;
- u32 cr1;
- u32 data;
- u32 sr;
- u32 cpsr;
- u32 imsc;
- u32 ris;
- u32 mis;
- u32 icr;
- u32 dmacr;
-};
-
-/* CR1 register defines */
-#define SSP_CR1_SSP_ENABLE 0x0002
-
-/* SR register defines */
-#define SSP_SR_TNF 0x0002
-/* SSP status RX FIFO not empty bit */
-#define SSP_SR_RNE 0x0004
-
-/* lpc32xx spi slave */
-struct lpc32xx_spi_slave {
- struct spi_slave slave;
- struct ssp_regs *regs;
-};
-
-static inline struct lpc32xx_spi_slave *to_lpc32xx_spi_slave(
- struct spi_slave *slave)
-{
- return container_of(slave, struct lpc32xx_spi_slave, slave);
-}
-
-/* the following is called in sequence by do_spi_xfer() */
-
-struct spi_slave *spi_setup_slave(uint bus, uint cs, uint max_hz, uint mode)
-{
- struct lpc32xx_spi_slave *lslave;
-
- /* we only set up SSP0 for now, so ignore bus */
-
- if (mode & SPI_3WIRE) {
- pr_err("3-wire mode not supported");
- return NULL;
- }
-
- if (mode & SPI_SLAVE) {
- pr_err("slave mode not supported\n");
- return NULL;
- }
-
- if (mode & SPI_PREAMBLE) {
- pr_err("preamble byte skipping not supported\n");
- return NULL;
- }
-
- lslave = spi_alloc_slave(struct lpc32xx_spi_slave, bus, cs);
- if (!lslave) {
- printf("SPI_error: Fail to allocate lpc32xx_spi_slave\n");
- return NULL;
- }
-
- lslave->regs = (struct ssp_regs *)SSP0_BASE;
-
- /*
- * 8 bit frame, SPI fmt, 500kbps -> clock divider is 26.
- * Set SCR to 0 and CPSDVSR to 26.
- */
-
- writel(0x7, &lslave->regs->cr0); /* 8-bit chunks, SPI, 1 clk/bit */
- writel(26, &lslave->regs->cpsr); /* SSP clock = HCLK/26 = 500kbps */
- writel(0, &lslave->regs->imsc); /* do not raise any interrupts */
- writel(0, &lslave->regs->icr); /* clear any pending interrupt */
- writel(0, &lslave->regs->dmacr); /* do not do DMAs */
- writel(SSP_CR1_SSP_ENABLE, &lslave->regs->cr1); /* enable SSP0 */
- return &lslave->slave;
-}
-
-void spi_free_slave(struct spi_slave *slave)
-{
- struct lpc32xx_spi_slave *lslave = to_lpc32xx_spi_slave(slave);
-
- debug("(lpc32xx) spi_free_slave: 0x%08x\n", (u32)lslave);
- free(lslave);
-}
-
-int spi_claim_bus(struct spi_slave *slave)
-{
- /* only one bus and slave so far, always available */
- return 0;
-}
-
-int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
- const void *dout, void *din, unsigned long flags)
-{
- struct lpc32xx_spi_slave *lslave = to_lpc32xx_spi_slave(slave);
- int bytelen = bitlen >> 3;
- int idx_out = 0;
- int idx_in = 0;
- int start_time;
-
- start_time = get_timer(0);
- while ((idx_out < bytelen) || (idx_in < bytelen)) {
- int status = readl(&lslave->regs->sr);
- if ((idx_out < bytelen) && (status & SSP_SR_TNF))
- writel(((u8 *)dout)[idx_out++], &lslave->regs->data);
- if ((idx_in < bytelen) && (status & SSP_SR_RNE))
- ((u8 *)din)[idx_in++] = readl(&lslave->regs->data);
- if (get_timer(start_time) >= CONFIG_LPC32XX_SSP_TIMEOUT)
- return -1;
- }
- return 0;
-}
-
-void spi_release_bus(struct spi_slave *slave)
-{
- /* do nothing */
-}
projects / u-boot.git / commitdiff