diff mbox series

[v6,02/12] spi: intel-dg: implement region enumeration

Message ID 20240916134928.3654054-3-alexander.usyskin@intel.com (mailing list archive)
State New
Headers show
Series spi: add driver for Intel discrete graphics | expand

Commit Message

Usyskin, Alexander Sept. 16, 2024, 1:49 p.m. UTC
From: Tomas Winkler <tomas.winkler@intel.com>

In intel-dg spi, there is no access to the spi controller,
the information is extracted from the descriptor region.

CC: Rodrigo Vivi <rodrigo.vivi@intel.com>
CC: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
---
 drivers/spi/spi-intel-dg.c | 190 +++++++++++++++++++++++++++++++++++++
 1 file changed, 190 insertions(+)

Comments

Mark Brown Sept. 18, 2024, 1:35 p.m. UTC | #1
On Mon, Sep 16, 2024 at 04:49:18PM +0300, Alexander Usyskin wrote:

> In intel-dg spi, there is no access to the spi controller,
> the information is extracted from the descriptor region.

Which information?  I can't tell what this patch is supposed to do; as
with the first patch this shouldn't be standalone.

> +static inline u32 spi_error(struct intel_dg_spi *spi)
> +{

> +static inline u32 spi_read32(struct intel_dg_spi *spi, u32 address)
> +{

At least these names are too generic, please use driver specific
prefixes.
Winkler, Tomas Sept. 19, 2024, 9:55 a.m. UTC | #2
> 
> On Mon, Sep 16, 2024 at 04:49:18PM +0300, Alexander Usyskin wrote:
> 
> > In intel-dg spi, there is no access to the spi controller, the
> > information is extracted from the descriptor region.
> 
> Which information?  I can't tell what this patch is supposed to do; as with the
> first patch this shouldn't be standalone.

The patch series was built for review, it adds functionality on top of each other. 

> 
> > +static inline u32 spi_error(struct intel_dg_spi *spi) {
> 
> > +static inline u32 spi_read32(struct intel_dg_spi *spi, u32 address) {
> 
> At least these names are too generic, please use driver specific prefixes.

Can be done but those functions are local to the driver not part of the API.
Mark Brown Sept. 19, 2024, 10:34 a.m. UTC | #3
On Thu, Sep 19, 2024 at 09:55:54AM +0000, Winkler, Tomas wrote:
> > On Mon, Sep 16, 2024 at 04:49:18PM +0300, Alexander Usyskin wrote:

> > > In intel-dg spi, there is no access to the spi controller, the
> > > information is extracted from the descriptor region.

> > Which information?  I can't tell what this patch is supposed to do; as with the
> > first patch this shouldn't be standalone.

> The patch series was built for review, it adds functionality on top of each other. 

That's not worked out well here - like I say I can't tell what the patch
is supposed to be doing.  What information is supposed to be read here,
why?

> > > +static inline u32 spi_error(struct intel_dg_spi *spi) {

> > > +static inline u32 spi_read32(struct intel_dg_spi *spi, u32 address) {

> > At least these names are too generic, please use driver specific prefixes.

> Can be done but those functions are local to the driver not part of the API.

Sure, the issue is that a core API with the same name could reasonably
be added at which point it'll collide with the driver internals.
diff mbox series

Patch

diff --git a/drivers/spi/spi-intel-dg.c b/drivers/spi/spi-intel-dg.c
index 4e302957f077..661e5189fa58 100644
--- a/drivers/spi/spi-intel-dg.c
+++ b/drivers/spi/spi-intel-dg.c
@@ -17,14 +17,197 @@  struct intel_dg_spi {
 	void __iomem *base;
 	size_t size;
 	unsigned int nregions;
+	u32 access_map;
 	struct {
 		const char *name;
 		u8 id;
 		u64 offset;
 		u64 size;
+		unsigned int is_readable:1;
+		unsigned int is_writable:1;
 	} regions[];
 };
 
+#define SPI_TRIGGER_REG       0x00000000
+#define SPI_VALSIG_REG        0x00000010
+#define SPI_ADDRESS_REG       0x00000040
+#define SPI_REGION_ID_REG     0x00000044
+/*
+ * [15:0]-Erase size = 0x0010 4K 0x0080 32K 0x0100 64K
+ * [23:16]-Reserved
+ * [31:24]-Erase SPI RegionID
+ */
+#define SPI_ERASE_REG         0x00000048
+#define SPI_ACCESS_ERROR_REG  0x00000070
+#define SPI_ADDRESS_ERROR_REG 0x00000074
+
+/* Flash Valid Signature */
+#define SPI_FLVALSIG          0x0FF0A55A
+
+#define SPI_MAP_ADDR_MASK     0x000000FF
+#define SPI_MAP_ADDR_SHIFT    0x00000004
+
+#define REGION_ID_DESCRIPTOR  0
+/* Flash Region Base Address */
+#define FRBA      0x40
+/* Flash Region __n - Flash Descriptor Record */
+#define FLREG(__n)  (FRBA + ((__n) * 4))
+/*  Flash Map 1 Register */
+#define FLMAP1_REG  0x18
+#define FLMSTR4_OFFSET 0x00C
+
+#define SPI_ACCESS_ERROR_PCIE_MASK 0x7
+
+static inline void spi_set_region_id(struct intel_dg_spi *spi, u8 region)
+{
+	iowrite32((u32)region, spi->base + SPI_REGION_ID_REG);
+}
+
+static inline u32 spi_error(struct intel_dg_spi *spi)
+{
+	u32 reg = ioread32(spi->base + SPI_ACCESS_ERROR_REG) &
+		  SPI_ACCESS_ERROR_PCIE_MASK;
+
+	/* reset error bits */
+	if (reg)
+		iowrite32(reg, spi->base + SPI_ACCESS_ERROR_REG);
+
+	return reg;
+}
+
+static inline u32 spi_read32(struct intel_dg_spi *spi, u32 address)
+{
+	void __iomem *base = spi->base;
+
+	iowrite32(address, base + SPI_ADDRESS_REG);
+
+	return ioread32(base + SPI_TRIGGER_REG);
+}
+
+static int spi_get_access_map(struct intel_dg_spi *spi)
+{
+	u32 flmap1;
+	u32 fmba;
+	u32 fmstr4;
+	u32 fmstr4_addr;
+
+	spi_set_region_id(spi, REGION_ID_DESCRIPTOR);
+
+	flmap1 = spi_read32(spi, FLMAP1_REG);
+	if (spi_error(spi))
+		return -EIO;
+	/* Get Flash Master Baser Address (FMBA) */
+	fmba = ((flmap1 & SPI_MAP_ADDR_MASK) << SPI_MAP_ADDR_SHIFT);
+	fmstr4_addr = fmba + FLMSTR4_OFFSET;
+
+	fmstr4 = spi_read32(spi, fmstr4_addr);
+	if (spi_error(spi))
+		return -EIO;
+
+	spi->access_map = fmstr4;
+	return 0;
+}
+
+static bool spi_region_readable(struct intel_dg_spi *spi, u8 region)
+{
+	if (region < 12)
+		return spi->access_map & (1 << (region + 8)); /* [19:8] */
+	else
+		return spi->access_map & (1 << (region - 12)); /* [3:0] */
+}
+
+static bool spi_region_writeable(struct intel_dg_spi *spi, u8 region)
+{
+	if (region < 12)
+		return spi->access_map & (1 << (region + 20)); /* [31:20] */
+	else
+		return spi->access_map & (1 << (region - 8)); /* [7:4] */
+}
+
+static int intel_dg_spi_is_valid(struct intel_dg_spi *spi)
+{
+	u32 is_valid;
+
+	spi_set_region_id(spi, REGION_ID_DESCRIPTOR);
+
+	is_valid = spi_read32(spi, SPI_VALSIG_REG);
+	if (spi_error(spi))
+		return -EIO;
+
+	if (is_valid != SPI_FLVALSIG)
+		return -ENODEV;
+
+	return 0;
+}
+
+static int intel_dg_spi_init(struct intel_dg_spi *spi, struct device *device)
+{
+	int ret;
+	unsigned int i, n;
+
+	/* clean error register, previous errors are ignored */
+	spi_error(spi);
+
+	ret = intel_dg_spi_is_valid(spi);
+	if (ret) {
+		dev_err(device, "The SPI is not valid %d\n", ret);
+		return ret;
+	}
+
+	if (spi_get_access_map(spi))
+		return -EIO;
+
+	for (i = 0, n = 0; i < spi->nregions; i++) {
+		u32 address, base, limit, region;
+		u8 id = spi->regions[i].id;
+
+		address = FLREG(id);
+		region = spi_read32(spi, address);
+
+		base = (region & 0x0000FFFF) << 12;
+		limit = (((region & 0xFFFF0000) >> 16) << 12) | 0xFFF;
+
+		dev_dbg(device, "[%d] %s: region: 0x%08X base: 0x%08x limit: 0x%08x\n",
+			id, spi->regions[i].name, region, base, limit);
+
+		if (base >= limit || (i > 0 && limit == 0)) {
+			dev_dbg(device, "[%d] %s: disabled\n",
+				id, spi->regions[i].name);
+			spi->regions[i].is_readable = 0;
+			continue;
+		}
+
+		if (spi->size < limit)
+			spi->size = limit;
+
+		spi->regions[i].offset = base;
+		spi->regions[i].size = limit - base + 1;
+		/* No write access to descriptor; mask it out*/
+		spi->regions[i].is_writable = spi_region_writeable(spi, id);
+
+		spi->regions[i].is_readable = spi_region_readable(spi, id);
+		dev_dbg(device, "Registered, %s id=%d offset=%lld size=%lld rd=%d wr=%d\n",
+			spi->regions[i].name,
+			spi->regions[i].id,
+			spi->regions[i].offset,
+			spi->regions[i].size,
+			spi->regions[i].is_readable,
+			spi->regions[i].is_writable);
+
+		if (spi->regions[i].is_readable)
+			n++;
+	}
+
+	dev_dbg(device, "Registered %d regions\n", n);
+
+	/* Need to add 1 to the amount of memory
+	 * so it is reported as an even block
+	 */
+	spi->size += 1;
+
+	return n;
+}
+
 static void intel_dg_spi_release(struct kref *kref)
 {
 	struct intel_dg_spi *spi = container_of(kref, struct intel_dg_spi, refcnt);
@@ -92,6 +275,13 @@  static int intel_dg_spi_probe(struct auxiliary_device *aux_dev,
 		goto err;
 	}
 
+	ret = intel_dg_spi_init(spi, device);
+	if (ret < 0) {
+		dev_err(device, "cannot initialize spi\n");
+		ret = -ENODEV;
+		goto err;
+	}
+
 	dev_set_drvdata(&aux_dev->dev, spi);
 
 	return 0;