diff options
Diffstat (limited to 'drivers/spi/atmel_spi.c')
| -rw-r--r-- | drivers/spi/atmel_spi.c | 286 |
1 files changed, 85 insertions, 201 deletions
diff --git a/drivers/spi/atmel_spi.c b/drivers/spi/atmel_spi.c index f076e92..b120664 100644 --- a/drivers/spi/atmel_spi.c +++ b/drivers/spi/atmel_spi.c @@ -9,217 +9,102 @@ #include <spi.h> #include <malloc.h> #include <wait_bit.h> - #include <asm/io.h> - #include <asm/arch/clk.h> #include <asm/arch/hardware.h> -#ifdef CONFIG_DM_SPI #include <asm/arch/at91_spi.h> -#endif #if CONFIG_IS_ENABLED(DM_GPIO) #include <asm/gpio.h> #endif +#include <linux/bitops.h> -#include "atmel_spi.h" - -#ifndef CONFIG_DM_SPI - -static int spi_has_wdrbt(struct atmel_spi_slave *slave) -{ - unsigned int ver; - - ver = spi_readl(slave, VERSION); - - return (ATMEL_SPI_VERSION_REV(ver) >= 0x210); -} - -struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, - unsigned int max_hz, unsigned int mode) -{ - struct atmel_spi_slave *as; - unsigned int scbr; - u32 csrx; - void *regs; - - if (!spi_cs_is_valid(bus, cs)) - return NULL; - - switch (bus) { - case 0: - regs = (void *)ATMEL_BASE_SPI0; - break; -#ifdef ATMEL_BASE_SPI1 - case 1: - regs = (void *)ATMEL_BASE_SPI1; - break; -#endif -#ifdef ATMEL_BASE_SPI2 - case 2: - regs = (void *)ATMEL_BASE_SPI2; - break; -#endif -#ifdef ATMEL_BASE_SPI3 - case 3: - regs = (void *)ATMEL_BASE_SPI3; - 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; - - as = spi_alloc_slave(struct atmel_spi_slave, bus, cs); - if (!as) - return NULL; - - as->regs = regs; - as->mr = ATMEL_SPI_MR_MSTR | ATMEL_SPI_MR_MODFDIS - | ATMEL_SPI_MR_PCS(~(1 << cs) & 0xf); - if (spi_has_wdrbt(as)) - as->mr |= ATMEL_SPI_MR_WDRBT; - - spi_writel(as, CSR(cs), csrx); - - return &as->slave; -} - -void spi_free_slave(struct spi_slave *slave) -{ - struct atmel_spi_slave *as = to_atmel_spi(slave); - - free(as); -} - -int spi_claim_bus(struct spi_slave *slave) -{ - struct atmel_spi_slave *as = to_atmel_spi(slave); - - /* Enable the SPI hardware */ - spi_writel(as, CR, ATMEL_SPI_CR_SPIEN); - - /* - * Select the slave. This should set SCK to the correct - * initial state, etc. - */ - spi_writel(as, MR, as->mr); - - return 0; -} - -void spi_release_bus(struct spi_slave *slave) -{ - struct atmel_spi_slave *as = to_atmel_spi(slave); - - /* Disable the SPI hardware */ - spi_writel(as, CR, ATMEL_SPI_CR_SPIDIS); -} - -int spi_xfer(struct spi_slave *slave, unsigned int bitlen, - const void *dout, void *din, unsigned long flags) -{ - struct atmel_spi_slave *as = to_atmel_spi(slave); - 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) - /* Finish any previously submitted transfers */ - goto out; - - /* - * 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) { - /* Errors always terminate an ongoing transfer */ - flags |= SPI_XFER_END; - goto out; - } - - 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); - /* - * sometimes the RDR is not empty when we get here, - * in theory that should not happen, but it DOES happen. - * Read it here to be on the safe side. - * That also clears the OVRES flag. Required if the - * following loop exits due to OVRES! - */ - spi_readl(as, RDR); - } - - for (len_tx = 0, len_rx = 0; len_rx < len; ) { - status = spi_readl(as, 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(as, TDR, value); - len_tx++; - } - if (status & ATMEL_SPI_SR_RDRF) { - value = spi_readl(as, RDR); - if (rxp) - *rxp++ = value; - len_rx++; - } - } - -out: - if (flags & SPI_XFER_END) { - /* - * Wait until the transfer is completely done before - * we deactivate CS. - */ - do { - status = spi_readl(as, SR); - } while (!(status & ATMEL_SPI_SR_TXEMPTY)); - - spi_cs_deactivate(slave); - } - - return 0; -} - -#else +/* + * 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 BIT(0) +#define ATMEL_SPI_CR_SPIDIS BIT(1) +#define ATMEL_SPI_CR_SWRST BIT(7) +#define ATMEL_SPI_CR_LASTXFER BIT(24) + +/* Bits in MR */ +#define ATMEL_SPI_MR_MSTR BIT(0) +#define ATMEL_SPI_MR_PS BIT(1) +#define ATMEL_SPI_MR_PCSDEC BIT(2) +#define ATMEL_SPI_MR_FDIV BIT(3) +#define ATMEL_SPI_MR_MODFDIS BIT(4) +#define ATMEL_SPI_MR_WDRBT BIT(5) +#define ATMEL_SPI_MR_LLB BIT(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 BIT(24) + +/* Bits in SR/IER/IDR/IMR */ +#define ATMEL_SPI_SR_RDRF BIT(0) +#define ATMEL_SPI_SR_TDRE BIT(1) +#define ATMEL_SPI_SR_MODF BIT(2) +#define ATMEL_SPI_SR_OVRES BIT(3) +#define ATMEL_SPI_SR_ENDRX BIT(4) +#define ATMEL_SPI_SR_ENDTX BIT(5) +#define ATMEL_SPI_SR_RXBUFF BIT(6) +#define ATMEL_SPI_SR_TXBUFE BIT(7) +#define ATMEL_SPI_SR_NSSR BIT(8) +#define ATMEL_SPI_SR_TXEMPTY BIT(9) +#define ATMEL_SPI_SR_SPIENS BIT(16) + +/* Bits in CSRx */ +#define ATMEL_SPI_CSRx_CPOL BIT(0) +#define ATMEL_SPI_CSRx_NCPHA BIT(1) +#define ATMEL_SPI_CSRx_CSAAT BIT(3) +#define ATMEL_SPI_CSRx_BITS(x) ((x) << 4) +#define ATMEL_SPI_CSRx_SCBR(x) ((x) << 8) +#define ATMEL_SPI_CSRx_SCBR_MAX GENMASK(7, 0) +#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) & 0xfff) +#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 #define MAX_CS_COUNT 4 +/* Register access macros */ +#define spi_readl(as, reg) \ + readl(as->regs + ATMEL_SPI_##reg) +#define spi_writel(as, reg, value) \ + writel(value, as->regs + ATMEL_SPI_##reg) + struct atmel_spi_platdata { struct at91_spi *regs; }; @@ -507,4 +392,3 @@ U_BOOT_DRIVER(atmel_spi) = { .priv_auto_alloc_size = sizeof(struct atmel_spi_priv), .probe = atmel_spi_probe, }; -#endif |