[U-Boot-Users] [RFC/PATCH] atmel_spi: Driver for the Atmel SPI controller
Haavard Skinnemoen
haavard.skinnemoen at atmel.com
Fri May 9 17:21:24 CEST 2008
From: Hans-Christian Egtvedt <hcegtvedt at atmel.com>
This adds a driver for the SPI controller found on most AT91 and AVR32
chips.
Currently, AT91RM9200 seems to have a SPI framework on its own. It
probably makes sense to merge the two drivers and make AT91RM9200 use
the framework everyone else uses at some point...
Signed-off-by: Haavard Skinnemoen <hskinnemoen at atmel.com>
---
cpu/at32ap/at32ap700x/gpio.c | 34 ++++
drivers/spi/Makefile | 1 +
drivers/spi/atmel_spi.c | 194 +++++++++++++++++++++
drivers/spi/atmel_spi.h | 90 ++++++++++
include/asm-avr32/arch-at32ap700x/chip-features.h | 1 +
include/asm-avr32/arch-at32ap700x/clk.h | 6 +
include/asm-avr32/arch-at32ap700x/gpio.h | 4 +
7 files changed, 330 insertions(+), 0 deletions(-)
create mode 100644 drivers/spi/atmel_spi.c
create mode 100644 drivers/spi/atmel_spi.h
diff --git a/cpu/at32ap/at32ap700x/gpio.c b/cpu/at32ap/at32ap700x/gpio.c
index 859124a..68527cb 100644
--- a/cpu/at32ap/at32ap700x/gpio.c
+++ b/cpu/at32ap/at32ap700x/gpio.c
@@ -142,3 +142,37 @@ void gpio_enable_mmci(void)
gpio_select_periph_A(GPIO_PIN_PA15, 0); /* DATA3 */
}
#endif
+
+#ifdef AT32AP700x_CHIP_HAS_SPI
+void gpio_enable_spi0(unsigned long cs_mask)
+{
+ gpio_select_periph_A(GPIO_PIN_PA0, 0); /* MISO */
+ gpio_select_periph_A(GPIO_PIN_PA1, 0); /* MOSI */
+ gpio_select_periph_A(GPIO_PIN_PA2, 0); /* SCK */
+
+ if (cs_mask & (1 << 0))
+ gpio_select_periph_A(GPIO_PIN_PA3, 0); /* NPCS0 */
+ if (cs_mask & (1 << 1))
+ gpio_select_periph_A(GPIO_PIN_PA4, 0); /* NPCS1 */
+ if (cs_mask & (1 << 2))
+ gpio_select_periph_A(GPIO_PIN_PA5, 0); /* NPCS2 */
+ if (cs_mask & (1 << 3))
+ gpio_select_periph_B(GPIO_PIN_PA20, 0); /* NPCS3 */
+}
+
+void gpio_enable_spi1(unsigned long cs_mask)
+{
+ gpio_select_periph_B(GPIO_PIN_PA0, 0); /* MISO */
+ gpio_select_periph_B(GPIO_PIN_PB1, 0); /* MOSI */
+ gpio_select_periph_B(GPIO_PIN_PB5, 0); /* SCK */
+
+ if (cs_mask & (1 << 0))
+ gpio_select_periph_B(GPIO_PIN_PB2, 0); /* NPCS0 */
+ if (cs_mask & (1 << 1))
+ gpio_select_periph_B(GPIO_PIN_PB3, 0); /* NPCS1 */
+ if (cs_mask & (1 << 2))
+ gpio_select_periph_B(GPIO_PIN_PB4, 0); /* NPCS2 */
+ if (cs_mask & (1 << 3))
+ gpio_select_periph_A(GPIO_PIN_PA27, 0); /* NPCS3 */
+}
+#endif
\ No newline at end of file
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index bc8a104..e66e0ee 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -26,6 +26,7 @@ include $(TOPDIR)/config.mk
LIB := $(obj)libspi.a
COBJS-y += mpc8xxx_spi.o
+COBJS-$(CONFIG_ATMEL_SPI) += atmel_spi.o
COBJS-$(CONFIG_MXC_SPI) += mxc_spi.o
COBJS := $(COBJS-y)
diff --git a/drivers/spi/atmel_spi.c b/drivers/spi/atmel_spi.c
new file mode 100644
index 0000000..6700d6b
--- /dev/null
+++ b/drivers/spi/atmel_spi.c
@@ -0,0 +1,194 @@
+/*
+ * Copyright (C) 2007 Atmel Corporation
+ *
+ * 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 <spi.h>
+#include <malloc.h>
+
+#include <asm/io.h>
+
+#include <asm/arch/clk.h>
+#include <asm/arch/memory-map.h>
+
+#include "atmel_spi.h"
+
+void spi_init()
+{
+
+}
+
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+ unsigned int max_hz, unsigned int mode)
+{
+ struct spi_slave *slave;
+ unsigned int scbr;
+ u32 csrx;
+ void *regs;
+
+ if (cs > 3 || !spi_cs_is_valid(bus, cs))
+ return NULL;
+
+ switch (bus) {
+ case 0:
+ regs = (void *)SPI0_BASE;
+ break;
+#ifdef SPI1_BASE
+ case 1:
+ regs = (void *)SPI1_BASE;
+ break;
+#endif
+#ifdef SPI2_BASE
+ case 2:
+ regs = (void *)SPI2_BASE;
+ break;
+#endif
+#ifdef SPI3_BASE
+ case 3:
+ regs = (void *)SPI3_BASE;
+ break;
+#endif
+ default:
+ return NULL;
+ }
+
+
+ scbr = (get_spi_clk_rate(bus) + max_hz - 1) / max_hz;
+ if (scbr > ATMEL_SPI_CSRx_SCBR_MAX)
+ /* Too low max SCK rate */
+ return NULL;
+ if (scbr < 1)
+ scbr = 1;
+
+ csrx = ATMEL_SPI_CSRx_SCBR(scbr);
+ csrx |= ATMEL_SPI_CSRx_BITS(ATMEL_SPI_BITS_8);
+ if (!(mode & SPI_CPHA))
+ csrx |= ATMEL_SPI_CSRx_NCPHA;
+ if (mode & SPI_CPOL)
+ csrx |= ATMEL_SPI_CSRx_CPOL;
+
+ slave = malloc(sizeof(struct spi_slave));
+ if (!slave)
+ return NULL;
+
+ slave->regs = regs;
+ slave->mr = ATMEL_SPI_MR_MSTR | ATMEL_SPI_MR_MODFDIS
+ | ATMEL_SPI_MR_PCS(~(1 << cs) & 0xf);
+ spi_writel(slave, CSR(cs), csrx);
+
+ return slave;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+ free(slave);
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+ /* Enable the SPI hardware */
+ spi_writel(slave, CR, ATMEL_SPI_CR_SPIEN);
+
+ /*
+ * Select the slave. This should set SCK to the correct
+ * initial state, etc.
+ */
+ spi_writel(slave, MR, slave->mr);
+
+ return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+ /* Disable the SPI hardware */
+ spi_writel(slave, CR, ATMEL_SPI_CR_SPIDIS);
+}
+
+int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
+ const void *dout, void *din, unsigned long flags)
+{
+ unsigned int len_tx;
+ unsigned int len_rx;
+ unsigned int len;
+ u32 status;
+ const u8 *txp = dout;
+ u8 *rxp = din;
+ u8 value;
+
+ if (bitlen == 0)
+ return 0;
+
+ /*
+ * TODO: The controller can do non-multiple-of-8 bit
+ * transfers, but this driver currently doesn't support it.
+ *
+ * It's also not clear how such transfers are supposed to be
+ * represented as a stream of bytes...this is a limitation of
+ * the current SPI interface.
+ */
+ if (bitlen % 8)
+ return -1;
+
+ len = bitlen / 8;
+
+ /*
+ * The controller can do automatic CS control, but it is
+ * somewhat quirky, and it doesn't really buy us much anyway
+ * in the context of U-Boot.
+ */
+ if (flags & SPI_XFER_BEGIN)
+ spi_cs_activate(slave->cs);
+
+ for (len_tx = 0, len_rx = 0; len_rx < len; ) {
+ status = spi_readl(slave, SR);
+
+ if (status & ATMEL_SPI_SR_OVRES)
+ return -1;
+
+ if (len_tx < len && (status & ATMEL_SPI_SR_TDRE)) {
+ if (txp)
+ value = *txp++;
+ else
+ value = 0;
+ spi_writel(slave, TDR, value);
+ len_tx++;
+ }
+ if (status & ATMEL_SPI_SR_RDRF) {
+ value = spi_readl(slave, RDR);
+ if (rxp)
+ *rxp++ = value;
+ len_rx++;
+ }
+ }
+
+ if (flags & SPI_XFER_END) {
+ /*
+ * Wait until the transfer is completely done before
+ * we deactivate CS.
+ */
+ do {
+ status = spi_readl(slave, SR);
+ } while (!(status & ATMEL_SPI_SR_TXEMPTY));
+
+ spi_cs_deactivate(slave->cs);
+ }
+
+ return 0;
+}
diff --git a/drivers/spi/atmel_spi.h b/drivers/spi/atmel_spi.h
new file mode 100644
index 0000000..af1853a
--- /dev/null
+++ b/drivers/spi/atmel_spi.h
@@ -0,0 +1,90 @@
+/*
+ * Register definitions for the Atmel AT32/AT91 SPI Controller
+ */
+
+/* Register offsets */
+#define ATMEL_SPI_CR 0x0000
+#define ATMEL_SPI_MR 0x0004
+#define ATMEL_SPI_RDR 0x0008
+#define ATMEL_SPI_TDR 0x000c
+#define ATMEL_SPI_SR 0x0010
+#define ATMEL_SPI_IER 0x0014
+#define ATMEL_SPI_IDR 0x0018
+#define ATMEL_SPI_IMR 0x001c
+#define ATMEL_SPI_CSR(x) (0x0030 + 4 * (x))
+#define ATMEL_SPI_VERSION 0x00fc
+
+/* Bits in CR */
+#define ATMEL_SPI_CR_SPIEN (1 << 0)
+#define ATMEL_SPI_CR_SPIDIS (1 << 1)
+#define ATMEL_SPI_CR_SWRST (1 << 7)
+#define ATMEL_SPI_CR_LASTXFER (1 << 24)
+
+/* Bits in MR */
+#define ATMEL_SPI_MR_MSTR (1 << 0)
+#define ATMEL_SPI_MR_PS (1 << 1)
+#define ATMEL_SPI_MR_PCSDEC (1 << 2)
+#define ATMEL_SPI_MR_FDIV (1 << 3)
+#define ATMEL_SPI_MR_MODFDIS (1 << 4)
+#define ATMEL_SPI_MR_LLB (1 << 7)
+#define ATMEL_SPI_MR_PCS(x) (((x) & 15) << 16)
+#define ATMEL_SPI_MR_DLYBCS(x) ((x) << 24)
+
+/* Bits in RDR */
+#define ATMEL_SPI_RDR_RD(x) (x)
+#define ATMEL_SPI_RDR_PCS(x) ((x) << 16)
+
+/* Bits in TDR */
+#define ATMEL_SPI_TDR_TD(x) (x)
+#define ATMEL_SPI_TDR_PCS(x) ((x) << 16)
+#define ATMEL_SPI_TDR_LASTXFER (1 << 24)
+
+/* Bits in SR/IER/IDR/IMR */
+#define ATMEL_SPI_SR_RDRF (1 << 0)
+#define ATMEL_SPI_SR_TDRE (1 << 1)
+#define ATMEL_SPI_SR_MODF (1 << 2)
+#define ATMEL_SPI_SR_OVRES (1 << 3)
+#define ATMEL_SPI_SR_ENDRX (1 << 4)
+#define ATMEL_SPI_SR_ENDTX (1 << 5)
+#define ATMEL_SPI_SR_RXBUFF (1 << 6)
+#define ATMEL_SPI_SR_TXBUFE (1 << 7)
+#define ATMEL_SPI_SR_NSSR (1 << 8)
+#define ATMEL_SPI_SR_TXEMPTY (1 << 9)
+#define ATMEL_SPI_SR_SPIENS (1 << 16)
+
+/* Bits in CSRx */
+#define ATMEL_SPI_CSRx_CPOL (1 << 0)
+#define ATMEL_SPI_CSRx_NCPHA (1 << 1)
+#define ATMEL_SPI_CSRx_CSAAT (1 << 3)
+#define ATMEL_SPI_CSRx_BITS(x) ((x) << 4)
+#define ATMEL_SPI_CSRx_SCBR(x) ((x) << 8)
+#define ATMEL_SPI_CSRx_SCBR_MAX 0xff
+#define ATMEL_SPI_CSRx_DLYBS(x) ((x) << 16)
+#define ATMEL_SPI_CSRx_DLYBCT(x) ((x) << 24)
+
+/* Bits in VERSION */
+#define ATMEL_SPI_VERSION_REV(x) ((x) << 0)
+#define ATMEL_SPI_VERSION_MFN(x) ((x) << 16)
+
+/* Constants for CSRx:BITS */
+#define ATMEL_SPI_BITS_8 0
+#define ATMEL_SPI_BITS_9 1
+#define ATMEL_SPI_BITS_10 2
+#define ATMEL_SPI_BITS_11 3
+#define ATMEL_SPI_BITS_12 4
+#define ATMEL_SPI_BITS_13 5
+#define ATMEL_SPI_BITS_14 6
+#define ATMEL_SPI_BITS_15 7
+#define ATMEL_SPI_BITS_16 8
+
+struct spi_slave {
+ void *regs;
+ unsigned int cs;
+ u32 mr;
+};
+
+/* Register access macros */
+#define spi_readl(slave, reg) \
+ readl(slave->regs + ATMEL_SPI_##reg)
+#define spi_writel(slave, reg, value) \
+ writel(value, slave->regs + ATMEL_SPI_##reg)
diff --git a/include/asm-avr32/arch-at32ap700x/chip-features.h b/include/asm-avr32/arch-at32ap700x/chip-features.h
index 29b1fd6..c47107e 100644
--- a/include/asm-avr32/arch-at32ap700x/chip-features.h
+++ b/include/asm-avr32/arch-at32ap700x/chip-features.h
@@ -25,6 +25,7 @@
/* Currently, all the AP700x chips have these */
#define AT32AP700x_CHIP_HAS_USART
#define AT32AP700x_CHIP_HAS_MMCI
+#define AT32AP700x_CHIP_HAS_SPI
/* Only AP7000 has ethernet interface */
#ifdef CONFIG_AT32AP7000
diff --git a/include/asm-avr32/arch-at32ap700x/clk.h b/include/asm-avr32/arch-at32ap700x/clk.h
index 385319a..bd6f2e5 100644
--- a/include/asm-avr32/arch-at32ap700x/clk.h
+++ b/include/asm-avr32/arch-at32ap700x/clk.h
@@ -74,6 +74,12 @@ static inline unsigned long get_mci_clk_rate(void)
return get_pbb_clk_rate();
}
#endif
+#ifdef AT32AP700x_CHIP_HAS_SPI
+static inline unsigned long get_spi_clk_rate(unsigned int dev_id)
+{
+ return get_pba_clk_rate();
+}
+#endif
/* Board code may need the SDRAM base clock as a compile-time constant */
#define SDRAMC_BUS_HZ (MAIN_CLK_RATE >> CFG_CLKDIV_HSB)
diff --git a/include/asm-avr32/arch-at32ap700x/gpio.h b/include/asm-avr32/arch-at32ap700x/gpio.h
index b10a3e4..ef20cea 100644
--- a/include/asm-avr32/arch-at32ap700x/gpio.h
+++ b/include/asm-avr32/arch-at32ap700x/gpio.h
@@ -216,5 +216,9 @@ void gpio_enable_macb1(void);
#ifdef AT32AP700x_CHIP_HAS_MMCI
void gpio_enable_mmci(void);
#endif
+#ifdef AT32AP700x_CHIP_HAS_SPI
+void gpio_enable_spi0(unsigned long cs_mask);
+void gpio_enable_spi1(unsigned long cs_mask);
+#endif
#endif /* __ASM_AVR32_ARCH_GPIO_H__ */
--
1.5.5.1
More information about the U-Boot
mailing list