[U-Boot] [PATCH v7 5/7] mips: ath79: add spi driver

Wills Wang wills.wang at live.com
Fri Jan 22 10:24:11 CET 2016



On Sunday, January 17, 2016 03:37 AM, Daniel Schwierzeck wrote:
> Am Sonntag, den 17.01.2016, 02:13 +0800 schrieb Wills Wang:
>> Reviewed-by: Thomas Chou <thomas at wytron.com.tw>
>>
>> Signed-off-by: Wills Wang <wills.wang at live.com>
> Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck at gmail.com>
>
> nits below
>
>> ---
>>
>> Changes in v7:
>> - Define spi_cs_activate/spi_cs_deactivate
>> - Rename MHZ to ATH79_SPI_MHZ
>> - Use clrsetbits_32
>>
>> Changes in v6:
>> - Add rrw_delay in ath79_spi_priv for more accurate timing
>> - Remove ath79_spi_delay
>> - Calculate delay in ath79_spi_set_speed
>>
>> Changes in v5:
>> - remove ar933x_spi_platdata
>> - Import document "spi-ath79.txt" from kernel
>> - Add delay for bitbang operation
>>
>> Changes in v4:
>> - Use get_bus_freq instead of hardcode in SPI driver
>>
>> Changes in v3:
>> - Convert spi driver to driver model
>>
>> Changes in v2:
>> - Add a compatible spi driver
>>
>>   doc/device-tree-bindings/spi/spi-ath79.txt |  19 +++
>>   drivers/spi/Kconfig                        |   8 +
>>   drivers/spi/Makefile                       |   1 +
>>   drivers/spi/ath79_spi.c                    | 237
>> +++++++++++++++++++++++++++++
>>   4 files changed, 265 insertions(+)
>>   create mode 100644 doc/device-tree-bindings/spi/spi-ath79.txt
>>   create mode 100644 drivers/spi/ath79_spi.c
>>
>> diff --git a/doc/device-tree-bindings/spi/spi-ath79.txt b/doc/device
>> -tree-bindings/spi/spi-ath79.txt
>> new file mode 100644
>> index 0000000..3fd9d67
>> --- /dev/null
>> +++ b/doc/device-tree-bindings/spi/spi-ath79.txt
>> @@ -0,0 +1,19 @@
>> +Binding for Qualcomm Atheros AR7xxx/AR9xxx SPI controller
>> +
>> +Required properties:
>> +- compatible: has to be "qca,<soc-type>-spi", "qca,ar7100-spi" as
>> fallback.
>> +- reg: Base address and size of the controllers memory area
>> +- #address-cells: <1>, as required by generic SPI binding.
>> +- #size-cells: <0>, also as required by generic SPI binding.
>> +
>> +Child nodes as per the generic SPI binding.
>> +
>> +Example:
>> +
>> +	spi at 1f000000 {
>> +		compatible = "qca,ar9132-spi", "qca,ar7100-spi";
>> +		reg = <0x1f000000 0x10>;
>> +
>> +		#address-cells = <1>;
>> +		#size-cells = <0>;
>> +	};
>> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
>> index 2cdb110..0ab2741 100644
>> --- a/drivers/spi/Kconfig
>> +++ b/drivers/spi/Kconfig
>> @@ -23,6 +23,14 @@ config ALTERA_SPI
>>   	  IP core. Please find details on the "Embedded Peripherals
>> IP
>>   	  User Guide" of Altera.
>>   
>> +config ATH79_SPI
>> +	bool "Atheros SPI driver"
> you should add
>
> depends on ARCH_ATH79
>
Ok.
>> +	help
>> +	  Enable the Atheros ar7xxx/ar9xxx SoC SPI driver, it was
>> used
>> +	  to access SPI NOR flash and other SPI peripherals. This
>> driver
>> +	  uses driver model and requires a device tree binding to
>> operate.
>> +	  please refer to doc/device-tree-bindings/spi/spi
>> -ath79.txt.
>> +
>>   config CADENCE_QSPI
>>   	bool "Cadence QSPI driver"
>>   	help
>> diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
>> index 3eca745..7fb2926 100644
>> --- a/drivers/spi/Makefile
>> +++ b/drivers/spi/Makefile
>> @@ -17,6 +17,7 @@ endif
>>   
>>   obj-$(CONFIG_ALTERA_SPI) += altera_spi.o
>>   obj-$(CONFIG_ARMADA100_SPI) += armada100_spi.o
>> +obj-$(CONFIG_ATH79_SPI) += ath79_spi.o
>>   obj-$(CONFIG_ATMEL_DATAFLASH_SPI) += atmel_dataflash_spi.o
>>   obj-$(CONFIG_ATMEL_SPI) += atmel_spi.o
>>   obj-$(CONFIG_BFIN_SPI) += bfin_spi.o
>> diff --git a/drivers/spi/ath79_spi.c b/drivers/spi/ath79_spi.c
>> new file mode 100644
>> index 0000000..568548f
>> --- /dev/null
>> +++ b/drivers/spi/ath79_spi.c
>> @@ -0,0 +1,237 @@
>> +/*
>> + * Copyright (C) 2015-2016 Wills Wang <wills.wang at live.com>
>> + *
>> + * SPDX-License-Identifier: GPL-2.0+
>> + */
>> +
>> +#include <common.h>
>> +#include <spi.h>
>> +#include <dm.h>
>> +#include <div64.h>
>> +#include <errno.h>
>> +#include <asm/io.h>
>> +#include <asm/addrspace.h>
>> +#include <asm/types.h>
>> +#include <mach/ar71xx_regs.h>
>> +
>> +/* CLOCK_DIVIDER = 3 (SPI clock = 200 / 8 ~ 25 MHz) */
>> +#define ATH79_SPI_CLK_DIV(x)           (((x) >> 1) - 1)
>> +#define ATH79_SPI_RRW_DELAY_FACTOR     12000
>> +#define ATH79_SPI_MHZ                  (1000 * 1000)
>> +
>> +struct ath79_spi_priv {
>> +	void __iomem *regs;
>> +	u32 rrw_delay;
>> +};
>> +
>> +static inline u32 ath79_spi_read(struct udevice *bus, u32 offset)
>> +{
>> +	struct ath79_spi_priv *priv = dev_get_priv(bus);
>> +	return readl(priv->regs + offset);
>> +}
>> +
>> +static inline void ath79_spi_write(struct udevice *bus,
>> +					u32 val, u32 offset)
>> +{
>> +	struct ath79_spi_priv *priv = dev_get_priv(bus);
>> +	writel(val, priv->regs + offset);
>> +}
> actually you could use the I/O accessors directly, there is no need for
> wrapper functions. The same is true for your serial driver.
Ok.
The relevant line exceed 80 characters because of long register name.
> of
>> +
>> +static void spi_cs_activate(struct udevice *dev)
>> +{
>> +	struct udevice *bus = dev->parent;
> for a consistent use of the DM API, you should use dev_get_parent(dev)
>
Ok.
>> +
>> +	ath79_spi_write(bus, AR71XX_SPI_FS_GPIO, AR71XX_SPI_REG_FS);
>> +	ath79_spi_write(bus, AR71XX_SPI_IOC_CS_ALL,
>> AR71XX_SPI_REG_IOC);
>> +}
>> +
>> +static void spi_cs_deactivate(struct udevice *dev)
>> +{
>> +	struct udevice *bus = dev->parent;
>> +
>> +	ath79_spi_write(bus, AR71XX_SPI_IOC_CS_ALL,
>> AR71XX_SPI_REG_IOC);
>> +	ath79_spi_write(bus, 0, AR71XX_SPI_REG_FS);
>> +}
>> +
>> +static int ath79_spi_claim_bus(struct udevice *dev)
>> +{
>> +	return 0;
>> +}
>> +
>> +static int ath79_spi_release_bus(struct udevice *dev)
>> +{
>> +	return 0;
>> +}
>> +
>> +static int ath79_spi_xfer(struct udevice *dev, unsigned int bitlen,
>> +		const void *dout, void *din, unsigned long flags)
>> +{
>> +	struct udevice *bus = dev->parent;
>> +	struct ath79_spi_priv *priv = dev_get_priv(bus);
>> +	struct dm_spi_slave_platdata *slave =
>> dev_get_parent_platdata(dev);
>> +	u8 *rx = din;
>> +	const u8 *tx = dout;
>> +	u8 curbyte, curbitlen, restbits;
>> +	u32 bytes = bitlen / 8;
>> +	u32 out, in;
>> +	u64 tick;
>> +
>> +	if (flags & SPI_XFER_BEGIN)
>> +		spi_cs_activate(dev);
>> +
>> +	restbits = (bitlen % 8);
>> +	if (restbits)
>> +		bytes++;
>> +
>> +	out = AR71XX_SPI_IOC_CS_ALL & ~(AR71XX_SPI_IOC_CS(slave
>> ->cs));
>> +	while (bytes > 0) {
>> +		bytes--;
>> +		curbyte = 0;
>> +		if (tx)
>> +			curbyte = *tx++;
>> +
>> +		if (restbits && !bytes) {
>> +			curbitlen = restbits;
>> +			curbyte <<= 8 - restbits;
>> +		} else {
>> +			curbitlen = 8;
>> +		}
>> +
>> +		for (curbyte <<= (8 - curbitlen); curbitlen;
>> curbitlen--) {
>> +			if (curbyte & 0x80)
>> +				out |= AR71XX_SPI_IOC_DO;
>> +			else
>> +				out &= ~(AR71XX_SPI_IOC_DO);
>> +
>> +			ath79_spi_write(bus, out,
>> AR71XX_SPI_REG_IOC);
>> +
>> +			/* delay for low level */
>> +			if (priv->rrw_delay) {
>> +				tick = get_ticks() + priv
>> ->rrw_delay;
>> +				while (get_ticks() < tick)
>> +					/*NOP*/;
>> +			}
>> +
>> +			ath79_spi_write(bus, out |
>> AR71XX_SPI_IOC_CLK,
>> +					AR71XX_SPI_REG_IOC);
>> +
>> +			/* delay for high level */
>> +			if (priv->rrw_delay) {
>> +				tick = get_ticks() + priv
>> ->rrw_delay;
>> +				while (get_ticks() < tick)
>> +					/*NOP*/;
>> +			}
>> +
>> +			curbyte <<= 1;
>> +		}
>> +
>> +		if (!bytes)
>> +			ath79_spi_write(bus, out,
>> AR71XX_SPI_REG_IOC);
>> +
>> +		in = ath79_spi_read(bus, AR71XX_SPI_REG_RDS);
>> +		if (rx) {
>> +			if (restbits && !bytes)
>> +				*rx++ = (in << (8 - restbits));
>> +			else
>> +				*rx++ = in;
>> +		}
>> +	}
>> +
>> +	if (flags & SPI_XFER_END)
>> +		spi_cs_deactivate(dev);
>> +
>> +	return 0;
>> +}
>> +
>> +
>> +static int ath79_spi_set_speed(struct udevice *bus, uint speed)
>> +{
>> +	struct ath79_spi_priv *priv = dev_get_priv(bus);
>> +	u32 val, div = 0;
>> +	u64 time;
>> +
>> +	if (speed)
>> +		div = get_bus_freq(0) / speed;
>> +
>> +	if (div > 63)
>> +		div = 63;
>> +
>> +	if (div < 5)
>> +		div = 5;
>> +
>> +	/* calculate delay */
>> +	time = get_tbclk();
>> +	do_div(time, speed / 2);
>> +	val = get_bus_freq(0) / ATH79_SPI_MHZ;
>> +	val = ATH79_SPI_RRW_DELAY_FACTOR / val;
>> +	if (time > val)
>> +		priv->rrw_delay = time - val + 1;
>> +	else
>> +		priv->rrw_delay = 0;
>> +
>> +	ath79_spi_write(bus, AR71XX_SPI_FS_GPIO, AR71XX_SPI_REG_FS);
>> +	clrsetbits_32(priv->regs + AR71XX_SPI_REG_CTRL,
>> +		      AR71XX_SPI_CTRL_DIV_MASK,
>> ATH79_SPI_CLK_DIV(div));
>> +	ath79_spi_write(bus, 0, AR71XX_SPI_REG_FS);
>> +	return 0;
>> +}
>> +
>> +static int ath79_spi_set_mode(struct udevice *bus, uint mode)
>> +{
>> +	return 0;
>> +}
>> +
>> +static int ath79_spi_probe(struct udevice *bus)
>> +{
>> +	struct ath79_spi_priv *priv = dev_get_priv(bus);
>> +	fdt_addr_t addr;
>> +
>> +	addr = dev_get_addr(bus);
>> +	if (addr == FDT_ADDR_T_NONE)
>> +		return -EINVAL;
>> +
>> +	priv->regs = map_physmem(addr,
>> +				 AR71XX_SPI_SIZE,
>> +				 MAP_NOCACHE);
>> +
>> +	/* Init SPI Hardware, disable remap, set clock */
>> +	ath79_spi_write(bus, AR71XX_SPI_FS_GPIO, AR71XX_SPI_REG_FS);
>> +	ath79_spi_write(bus, AR71XX_SPI_CTRL_RD |
>> ATH79_SPI_CLK_DIV(8),
>> +			AR71XX_SPI_REG_CTRL);
>> +	ath79_spi_write(bus, 0, AR71XX_SPI_REG_FS);
>> +
>> +	return 0;
>> +}
>> +
>> +static int ath79_cs_info(struct udevice *bus, uint cs,
>> +			   struct spi_cs_info *info)
>> +{
>> +	/* Always allow activity on CS 0/1/2 */
>> +	if (cs >= 3)
>> +		return -ENODEV;
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct dm_spi_ops ath79_spi_ops = {
>> +	.claim_bus  = ath79_spi_claim_bus,
>> +	.release_bus    = ath79_spi_release_bus,
>> +	.xfer       = ath79_spi_xfer,
>> +	.set_speed  = ath79_spi_set_speed,
>> +	.set_mode   = ath79_spi_set_mode,
>> +	.cs_info    = ath79_cs_info,
>> +};
>> +
>> +static const struct udevice_id ath79_spi_ids[] = {
>> +	{ .compatible = "qca,ar7100-spi" },
>> +	{}
>> +};
>> +
>> +U_BOOT_DRIVER(ath79_spi) = {
>> +	.name   = "ath79_spi",
>> +	.id = UCLASS_SPI,
>> +	.of_match = ath79_spi_ids,
>> +	.ops    = &ath79_spi_ops,
>> +	.priv_auto_alloc_size = sizeof(struct ath79_spi_priv),
>> +	.probe  = ath79_spi_probe,
>> +};

-- 
Best Regards
Wills



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