drivers/spi/spi-bcmbca-hsspi.c

Source file repositories/reference/linux-study-clean/drivers/spi/spi-bcmbca-hsspi.c

File Facts

System
Linux kernel
Corpus path
drivers/spi/spi-bcmbca-hsspi.c
Extension
.c
Size
17029 bytes
Lines
628
Domain
Driver Families
Bucket
drivers/spi
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct bcmbca_hsspi {
	struct completion done;
	struct mutex bus_mutex;
	struct mutex msg_mutex;
	struct platform_device *pdev;
	struct clk *clk;
	struct clk *pll_clk;
	void __iomem *regs;
	void __iomem *spim_ctrl;
	u8 __iomem *fifo;
	u32 speed_hz;
	u8 cs_polarity;
	u32 wait_mode;
};

static ssize_t wait_mode_show(struct device *dev, struct device_attribute *attr,
			 char *buf)
{
	struct spi_controller *ctrl = dev_get_drvdata(dev);
	struct bcmbca_hsspi *bs = spi_controller_get_devdata(ctrl);

	return sprintf(buf, "%d\n", bs->wait_mode);
}

static ssize_t wait_mode_store(struct device *dev, struct device_attribute *attr,
			  const char *buf, size_t count)
{
	struct spi_controller *ctrl = dev_get_drvdata(dev);
	struct bcmbca_hsspi *bs = spi_controller_get_devdata(ctrl);
	u32 val;

	if (kstrtou32(buf, 10, &val))
		return -EINVAL;

	if (val > HSSPI_WAIT_MODE_MAX) {
		dev_warn(dev, "invalid wait mode %u\n", val);
		return -EINVAL;
	}

	mutex_lock(&bs->msg_mutex);
	bs->wait_mode = val;
	/* clear interrupt status to avoid spurious int on next transfer */
	if (val == HSSPI_WAIT_MODE_INTR)
		__raw_writel(HSSPI_INT_CLEAR_ALL, bs->regs + HSSPI_INT_STATUS_REG);
	mutex_unlock(&bs->msg_mutex);

	return count;
}

static DEVICE_ATTR_RW(wait_mode);

static struct attribute *bcmbca_hsspi_attrs[] = {
	&dev_attr_wait_mode.attr,
	NULL,
};

static const struct attribute_group bcmbca_hsspi_group = {
	.attrs = bcmbca_hsspi_attrs,
};

static void bcmbca_hsspi_set_cs(struct bcmbca_hsspi *bs, unsigned int cs,
				 bool active)
{
	u32 reg;

	/* No cs orerriden needed for SS7 internal cs on pcm based voice dev */
	if (cs == 7)
		return;

	mutex_lock(&bs->bus_mutex);

	reg = __raw_readl(bs->spim_ctrl);
	if (active)
		reg |= BIT(cs + SPIM_CTRL_CS_OVERRIDE_SEL_SHIFT);
	else
		reg &= ~BIT(cs + SPIM_CTRL_CS_OVERRIDE_SEL_SHIFT);

	__raw_writel(reg, bs->spim_ctrl);

	mutex_unlock(&bs->bus_mutex);
}

static void bcmbca_hsspi_set_clk(struct bcmbca_hsspi *bs,
				  struct spi_device *spi, int hz)
{
	unsigned int profile = spi_get_chipselect(spi, 0);
	u32 reg;

	reg = DIV_ROUND_UP(2048, DIV_ROUND_UP(bs->speed_hz, hz));
	__raw_writel(CLK_CTRL_ACCUM_RST_ON_LOOP | reg,

Annotation

Implementation Notes