[PATCH 04/10] drm/i915/spi: implement region enumeration

Alexander Usyskin
2023-09-10T12:44:46Z

From: Tomas Winkler <tomas.winkler@intel.com>

In i915-spi, there is no access to the spi controller,
the information is extracted form 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/gpu/drm/i915/spi/intel_spi_drv.c | 193 ++++++++++++++++++++++-
1 file changed, 192 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/spi/intel_spi_drv.c b/drivers/gpu/drm/i915/spi/intel_spi_drv.c
index 15c77b4b38bb..f32ea05f4f64 100644
--- a/drivers/gpu/drm/i915/spi/intel_spi_drv.c
+++ b/drivers/gpu/drm/i915/spi/intel_spi_drv.c
@@ -2,11 +2,12 @@
/*
* Copyright(c) 2019-2022, Intel Corporation. All rights reserved.
*/
+
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
-#include <linux/ioport.h>
+#include <linux/io.h>
#include <linux/device.h>
#include <linux/slab.h>
#include "spi/intel_spi.h"
@@ -16,14 +17,197 @@ struct i915_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 i915_spi *spi, u8 region)
+{
+ iowrite32((u32)region, spi->base + SPI_REGION_ID_REG);
+}
+
+static inline u32 spi_error(struct i915_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 i915_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 i915_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 i915_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 i915_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 i915_spi_is_valid(struct i915_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 i915_spi_init(struct i915_spi *spi, struct device *device)
+{
+ int ret;
+ unsigned int i, n;
+
+ /* clean error register, previous errors are ignored */
+ spi_error(spi);
+
+ ret = i915_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 i915_spi_release(struct kref *kref)
{
struct i915_spi *spi = container_of(kref, struct i915_spi, refcnt);
@@ -91,6 +275,13 @@ static int i915_spi_probe(struct auxiliary_device *aux_dev,
goto err;
}

+ ret = i915_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);

dev_dbg(device, "i915-spi is bound\n");
--
2.34.1