[PATCH v6 03/11] mtd: intel-dg: implement region enumeration

Alexander Usyskin
2025-03-02T14:20:56Z

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

CC: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Co-developed-by: Tomas Winkler <tomasw@gmail.com>
Signed-off-by: Tomas Winkler <tomasw@gmail.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
---
drivers/mtd/devices/mtd_intel_dg.c | 198 +++++++++++++++++++++++++++++
1 file changed, 198 insertions(+)

diff --git a/drivers/mtd/devices/mtd_intel_dg.c b/drivers/mtd/devices/mtd_intel_dg.c
index 963a88cacc6c..ba1c720e717b 100644
--- a/drivers/mtd/devices/mtd_intel_dg.c
+++ b/drivers/mtd/devices/mtd_intel_dg.c
@@ -3,6 +3,8 @@
* Copyright(c) 2019-2025, Intel Corporation. All rights reserved.
*/

+#include <linux/bitfield.h>
+#include <linux/bits.h>
#include <linux/device.h>
#include <linux/intel_dg_nvm_aux.h>
#include <linux/io.h>
@@ -22,9 +24,199 @@ struct intel_dg_nvm {
u8 id;
u64 offset;
u64 size;
+ unsigned int is_readable:1;
+ unsigned int is_writable:1;
} regions[] __counted_by(nregions);
};

+#define NVM_TRIGGER_REG 0x00000000
+#define NVM_VALSIG_REG 0x00000010
+#define NVM_ADDRESS_REG 0x00000040
+#define NVM_REGION_ID_REG 0x00000044
+/*
+ * [15:0]-Erase size = 0x0010 4K 0x0080 32K 0x0100 64K
+ * [23:16]-Reserved
+ * [31:24]-Erase MEM RegionID
+ */
+#define NVM_ERASE_REG 0x00000048
+#define NVM_ACCESS_ERROR_REG 0x00000070
+#define NVM_ADDRESS_ERROR_REG 0x00000074
+
+/* Flash Valid Signature */
+#define NVM_FLVALSIG 0x0FF0A55A
+
+#define NVM_MAP_ADDR_MASK GENMASK(7, 0)
+#define NVM_MAP_ADDR_SHIFT 0x00000004
+
+#define NVM_REGION_ID_DESCRIPTOR 0
+/* Flash Region Base Address */
+#define NVM_FRBA 0x40
+/* Flash Region __n - Flash Descriptor Record */
+#define NVM_FLREG(__n) (NVM_FRBA + ((__n) * 4))
+/* Flash Map 1 Register */
+#define NVM_FLMAP1_REG 0x18
+#define NVM_FLMSTR4_OFFSET 0x00C
+
+#define NVM_ACCESS_ERROR_PCIE_MASK 0x7
+
+#define NVM_FREG_BASE_MASK GENMASK(15, 0)
+#define NVM_FREG_ADDR_MASK GENMASK(31, 16)
+#define NVM_FREG_ADDR_SHIFT 12
+#define NVM_FREG_MIN_REGION_SIZE 0xFFF
+
+static inline void idg_nvm_set_region_id(struct intel_dg_nvm *nvm, u8 region)
+{
+ iowrite32((u32)region, nvm->base + NVM_REGION_ID_REG);
+}
+
+static inline u32 idg_nvm_error(struct intel_dg_nvm *nvm)
+{
+ void __iomem *base = nvm->base;
+
+ u32 reg = ioread32(base + NVM_ACCESS_ERROR_REG) & NVM_ACCESS_ERROR_PCIE_MASK;
+
+ /* reset error bits */
+ if (reg)
+ iowrite32(reg, base + NVM_ACCESS_ERROR_REG);
+
+ return reg;
+}
+
+static inline u32 idg_nvm_read32(struct intel_dg_nvm *nvm, u32 address)
+{
+ void __iomem *base = nvm->base;
+
+ iowrite32(address, base + NVM_ADDRESS_REG);
+
+ return ioread32(base + NVM_TRIGGER_REG);
+}
+
+static int idg_nvm_get_access_map(struct intel_dg_nvm *nvm, u32 *access_map)
+{
+ u32 flmap1;
+ u32 fmba;
+ u32 fmstr4;
+ u32 fmstr4_addr;
+
+ idg_nvm_set_region_id(nvm, NVM_REGION_ID_DESCRIPTOR);
+
+ flmap1 = idg_nvm_read32(nvm, NVM_FLMAP1_REG);
+ if (idg_nvm_error(nvm))
+ return -EIO;
+ /* Get Flash Master Baser Address (FMBA) */
+ fmba = (FIELD_GET(NVM_MAP_ADDR_MASK, flmap1) << NVM_MAP_ADDR_SHIFT);
+ fmstr4_addr = fmba + NVM_FLMSTR4_OFFSET;
+
+ fmstr4 = idg_nvm_read32(nvm, fmstr4_addr);
+ if (idg_nvm_error(nvm))
+ return -EIO;
+
+ *access_map = fmstr4;
+ return 0;
+}
+
+static bool idg_nvm_region_readable(u32 access_map, u8 region)
+{
+ if (region < 12)
+ return access_map & BIT(region + 8); /* [19:8] */
+ else
+ return access_map & BIT(region - 12); /* [3:0] */
+}
+
+static bool idg_nvm_region_writable(u32 access_map, u8 region)
+{
+ if (region < 12)
+ return access_map & BIT(region + 20); /* [31:20] */
+ else
+ return access_map & BIT(region - 8); /* [7:4] */
+}
+
+static int idg_nvm_is_valid(struct intel_dg_nvm *nvm)
+{
+ u32 is_valid;
+
+ idg_nvm_set_region_id(nvm, NVM_REGION_ID_DESCRIPTOR);
+
+ is_valid = idg_nvm_read32(nvm, NVM_VALSIG_REG);
+ if (idg_nvm_error(nvm))
+ return -EIO;
+
+ if (is_valid != NVM_FLVALSIG)
+ return -ENODEV;
+
+ return 0;
+}
+
+static int intel_dg_nvm_init(struct intel_dg_nvm *nvm, struct device *device)
+{
+ int ret;
+ unsigned int i, n;
+ u32 access_map = 0;
+
+ /* clean error register, previous errors are ignored */
+ idg_nvm_error(nvm);
+
+ ret = idg_nvm_is_valid(nvm);
+ if (ret) {
+ dev_err(device, "The MEM is not valid %d\n", ret);
+ return ret;
+ }
+
+ if (idg_nvm_get_access_map(nvm, &access_map))
+ return -EIO;
+
+ for (i = 0, n = 0; i < nvm->nregions; i++) {
+ u32 address, base, limit, region;
+ u8 id = nvm->regions[i].id;
+
+ address = NVM_FLREG(id);
+ region = idg_nvm_read32(nvm, address);
+
+ base = FIELD_GET(NVM_FREG_BASE_MASK, region) << NVM_FREG_ADDR_SHIFT;
+ limit = (FIELD_GET(NVM_FREG_ADDR_MASK, region) << NVM_FREG_ADDR_SHIFT) |
+ NVM_FREG_MIN_REGION_SIZE;
+
+ dev_dbg(device, "[%d] %s: region: 0x%08X base: 0x%08x limit: 0x%08x\n",
+ id, nvm->regions[i].name, region, base, limit);
+
+ if (base >= limit || (i > 0 && limit == 0)) {
+ dev_dbg(device, "[%d] %s: disabled\n",
+ id, nvm->regions[i].name);
+ nvm->regions[i].is_readable = 0;
+ continue;
+ }
+
+ if (nvm->size < limit)
+ nvm->size = limit;
+
+ nvm->regions[i].offset = base;
+ nvm->regions[i].size = limit - base + 1;
+ /* No write access to descriptor; mask it out*/
+ nvm->regions[i].is_writable = idg_nvm_region_writable(access_map, id);
+
+ nvm->regions[i].is_readable = idg_nvm_region_readable(access_map, id);
+ dev_dbg(device, "Registered, %s id=%d offset=%lld size=%lld rd=%d wr=%d\n",
+ nvm->regions[i].name,
+ nvm->regions[i].id,
+ nvm->regions[i].offset,
+ nvm->regions[i].size,
+ nvm->regions[i].is_readable,
+ nvm->regions[i].is_writable);
+
+ if (nvm->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
+ */
+ nvm->size += 1;
+
+ return n;
+}
+
static void intel_dg_nvm_release(struct kref *kref)
{
struct intel_dg_nvm *nvm = container_of(kref, struct intel_dg_nvm, refcnt);
@@ -88,6 +280,12 @@ static int intel_dg_mtd_probe(struct auxiliary_device *aux_dev,
goto err;
}

+ ret = intel_dg_nvm_init(nvm, device);
+ if (ret < 0) {
+ dev_err(device, "cannot initialize nvm %d\n", ret);
+ goto err;
+ }
+
dev_set_drvdata(&aux_dev->dev, nvm);

return 0;
--
2.43.0