|
@@ -1,134 +0,0 @@
|
|
|
-// 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 */
|
|
|
-}
|