[PATCH v3 8/9] fpga: m10bmc-sec: Add support for N6000

[Ilpo Järvinen]

Add support for PMCI-based flash access path and N6000 sec update
support. Access to flash staging area is different for N6000 from that
of the SPI interfaced counterparts.

Introduce intel_m10bmc_flash_bulk_ops to allow interface specific
differentiations for the flash access path for sec update and make
m10bmc_sec_read/write() in sec update driver to use the new operations.

Co-developed-by: Tianfei zhang <tianfei.zhang@xxxxxxxxx>
Signed-off-by: Tianfei zhang <tianfei.zhang@xxxxxxxxx>
Co-developed-by: Russ Weight <russell.h.weight@xxxxxxxxx>
Signed-off-by: Russ Weight <russell.h.weight@xxxxxxxxx>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
---
 drivers/fpga/intel-m10-bmc-sec-update.c |  65 ++++++++++-
 drivers/mfd/intel-m10-bmc-pmci-main.c   | 145 ++++++++++++++++++++++++
 include/linux/mfd/intel-m10-bmc.h       |  14 +++
 3 files changed, 223 insertions(+), 1 deletion(-)

diff --git a/drivers/fpga/intel-m10-bmc-sec-update.c b/drivers/fpga/intel-m10-bmc-sec-update.c
index 9922027856a4..885e38f13897 100644
--- a/drivers/fpga/intel-m10-bmc-sec-update.c
+++ b/drivers/fpga/intel-m10-bmc-sec-update.c
@@ -14,6 +14,20 @@
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 
+#define M10BMC_PMCI_FLASH_MUX_CTRL	0x1d0
+#define FLASH_MUX_SELECTION		GENMASK(2, 0)
+#define FLASH_MUX_IDLE			0
+#define FLASH_MUX_NIOS			1
+#define FLASH_MUX_HOST			2
+#define FLASH_MUX_PFL			4
+#define get_flash_mux(mux)		FIELD_GET(FLASH_MUX_SELECTION, mux)
+
+#define FLASH_NIOS_REQUEST		BIT(4)
+#define FLASH_HOST_REQUEST		BIT(5)
+
+#define M10_FLASH_INT_US		1
+#define M10_FLASH_TIMEOUT_US		10000
+
 struct m10bmc_sec {
 	struct device *dev;
 	struct intel_m10bmc *m10bmc;
@@ -21,6 +35,7 @@ struct m10bmc_sec {
 	char *fw_name;
 	u32 fw_name_id;
 	bool cancel_request;
+	struct mutex flash_mutex;
 };
 
 static DEFINE_XARRAY_ALLOC(fw_upload_xa);
@@ -31,6 +46,24 @@ static DEFINE_XARRAY_ALLOC(fw_upload_xa);
 #define REH_MAGIC		GENMASK(15, 0)
 #define REH_SHA_NUM_BYTES	GENMASK(31, 16)
 
+static int m10bmc_sec_set_flash_host_mux(struct intel_m10bmc *m10bmc, bool request)
+{
+	u32 ctrl;
+	int ret;
+
+	ret = regmap_update_bits(m10bmc->regmap, M10BMC_PMCI_FLASH_MUX_CTRL,
+				 FLASH_HOST_REQUEST,
+				 FIELD_PREP(FLASH_HOST_REQUEST, request));
+	if (ret)
+		return ret;
+
+	return regmap_read_poll_timeout(m10bmc->regmap,
+					M10BMC_PMCI_FLASH_MUX_CTRL, ctrl,
+					request ? (get_flash_mux(ctrl) == FLASH_MUX_HOST) :
+						  (get_flash_mux(ctrl) != FLASH_MUX_HOST),
+					M10_FLASH_INT_US, M10_FLASH_TIMEOUT_US);
+}
+
 static int m10bmc_sec_write(struct m10bmc_sec *sec, const u8 *buf, u32 offset, u32 size)
 {
 	struct intel_m10bmc *m10bmc = sec->m10bmc;
@@ -41,6 +74,15 @@ static int m10bmc_sec_write(struct m10bmc_sec *sec, const u8 *buf, u32 offset, u
 	u32 leftover_tmp = 0;
 	int ret;
 
+	if (sec->m10bmc->flash_bulk_ops) {
+		mutex_lock(&sec->flash_mutex);
+		/* On write, firmware manages flash MUX */
+		ret = sec->m10bmc->flash_bulk_ops->write(m10bmc, buf, offset, size);
+		mutex_unlock(&sec->flash_mutex);
+
+		return ret;
+	}
+
 	if (WARN_ON_ONCE(stride > sizeof(leftover_tmp)))
 		return -EINVAL;
 
@@ -69,7 +111,21 @@ static int m10bmc_sec_read(struct m10bmc_sec *sec, u8 *buf, u32 addr, u32 size)
 	u32 leftover_offset = read_count * stride;
 	u32 leftover_size = size - leftover_offset;
 	u32 leftover_tmp;
-	int ret;
+	int ret, ret2;
+
+	if (sec->m10bmc->flash_bulk_ops) {
+		mutex_lock(&sec->flash_mutex);
+		ret = m10bmc_sec_set_flash_host_mux(m10bmc, true);
+		if (ret)
+			goto mux_fail;
+		ret = sec->m10bmc->flash_bulk_ops->read(m10bmc, buf, addr, size);
+mux_fail:
+		ret2 = m10bmc_sec_set_flash_host_mux(m10bmc, false);
+		mutex_unlock(&sec->flash_mutex);
+		if (ret)
+			return ret;
+		return ret2;
+	}
 
 	if (WARN_ON_ONCE(stride > sizeof(leftover_tmp)))
 		return -EINVAL;
@@ -611,6 +667,8 @@ static int m10bmc_sec_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	mutex_init(&sec->flash_mutex);
+
 	len = scnprintf(buf, SEC_UPDATE_LEN_MAX, "secure-update%d",
 			sec->fw_name_id);
 	sec->fw_name = kmemdup_nul(buf, len, GFP_KERNEL);
@@ -633,6 +691,7 @@ static int m10bmc_sec_probe(struct platform_device *pdev)
 fw_uploader_fail:
 	kfree(sec->fw_name);
 fw_name_fail:
+	mutex_destroy(&sec->flash_mutex);
 	xa_erase(&fw_upload_xa, sec->fw_name_id);
 	return ret;
 }
@@ -643,6 +702,7 @@ static int m10bmc_sec_remove(struct platform_device *pdev)
 
 	firmware_upload_unregister(sec->fwl);
 	kfree(sec->fw_name);
+	mutex_destroy(&sec->flash_mutex);
 	xa_erase(&fw_upload_xa, sec->fw_name_id);
 
 	return 0;
@@ -655,6 +715,9 @@ static const struct platform_device_id intel_m10bmc_sec_ids[] = {
 	{
 		.name = "d5005bmc-sec-update",
 	},
+	{
+		.name = "n6000bmc-sec-update",
+	},
 	{ }
 };
 MODULE_DEVICE_TABLE(platform, intel_m10bmc_sec_ids);
diff --git a/drivers/mfd/intel-m10-bmc-pmci-main.c b/drivers/mfd/intel-m10-bmc-pmci-main.c
index 11e528b2f707..ad9f731144b7 100644
--- a/drivers/mfd/intel-m10-bmc-pmci-main.c
+++ b/drivers/mfd/intel-m10-bmc-pmci-main.c
@@ -7,9 +7,11 @@
  *
  */
 
+#include <linux/bitfield.h>
 #include <linux/dfl.h>
 #include <linux/mfd/core.h>
 #include <linux/mfd/intel-m10-bmc.h>
+#include <linux/minmax.h>
 #include <linux/module.h>
 #include <linux/regmap.h>
 
@@ -45,11 +47,151 @@
 
 #define M10BMC_PMCI_STAGING_FLASH_COUNT	0x7ff5000
 
+#define M10BMC_PMCI_FLASH_CTRL			0x40
+#define M10BMC_PMCI_FLASH_WR_MODE		BIT(0)
+#define M10BMC_PMCI_FLASH_RD_MODE		BIT(1)
+#define M10BMC_PMCI_FLASH_BUSY			BIT(2)
+#define M10BMC_PMCI_FLASH_FIFO_SPACE		GENMASK(13, 4)
+#define M10BMC_PMCI_FLASH_READ_COUNT		GENMASK(25, 16)
+
+#define M10BMC_PMCI_FLASH_ADDR			0x44
+#define M10BMC_PMCI_FLASH_FIFO			0x800
+#define M10BMC_PMCI_READ_BLOCK_SIZE		0x800
+#define M10BMC_PMCI_FIFO_MAX_BYTES		0x800
+#define M10BMC_PMCI_FIFO_WORD_SIZE		4
+#define M10BMC_PMCI_FIFO_MAX_WORDS		(M10BMC_PMCI_FIFO_MAX_BYTES / \
+						 M10BMC_PMCI_FIFO_WORD_SIZE)
+
+#define M10BMC_PMCI_FLASH_INT_US		1
+#define M10BMC_PMCI_FLASH_TIMEOUT_US		10000
+
 struct m10bmc_pmci_device {
 	void __iomem *base;
 	struct intel_m10bmc m10bmc;
 };
 
+static void pmci_write_fifo(void __iomem *base, const u32 *buf, size_t count)
+{
+	while (count--)
+		writel(*buf++, base);
+}
+
+static void pmci_read_fifo(void __iomem *base, u32 *buf, size_t count)
+{
+	while (count--)
+		*buf++ = readl(base);
+}
+
+static u32 pmci_get_write_space(struct m10bmc_pmci_device *pmci)
+{
+	u32 val;
+	int ret;
+
+	ret = read_poll_timeout(readl, val,
+				FIELD_GET(M10BMC_PMCI_FLASH_FIFO_SPACE, val) ==
+				M10BMC_PMCI_FIFO_MAX_WORDS,
+				M10BMC_PMCI_FLASH_INT_US, M10BMC_PMCI_FLASH_TIMEOUT_US,
+				false, pmci->base + M10BMC_PMCI_FLASH_CTRL);
+	if (ret == -ETIMEDOUT)
+		return 0;
+
+	return FIELD_GET(M10BMC_PMCI_FLASH_FIFO_SPACE, val) * M10BMC_PMCI_FIFO_WORD_SIZE;
+}
+
+static int pmci_flash_bulk_write(struct intel_m10bmc *m10bmc, const u8 *buf, u32 size)
+{
+	struct m10bmc_pmci_device *pmci = container_of(m10bmc, struct m10bmc_pmci_device, m10bmc);
+	u32 blk_size, offset = 0, write_count;
+
+	while (size) {
+		blk_size = min(pmci_get_write_space(pmci), size);
+		if (blk_size == 0) {
+			dev_err(m10bmc->dev, "get FIFO available size fail\n");
+			return -EIO;
+		}
+
+		if (size < M10BMC_PMCI_FIFO_WORD_SIZE)
+			break;
+
+		write_count = blk_size / M10BMC_PMCI_FIFO_WORD_SIZE;
+		pmci_write_fifo(pmci->base + M10BMC_PMCI_FLASH_FIFO,
+				(u32 *)(buf + offset), write_count);
+
+		size -= blk_size;
+		offset += blk_size;
+	}
+
+	/* Handle remainder (less than M10BMC_PMCI_FIFO_WORD_SIZE bytes) */
+	if (size) {
+		u32 tmp = 0;
+
+		memcpy(&tmp, buf + offset, size);
+		pmci_write_fifo(pmci->base + M10BMC_PMCI_FLASH_FIFO, &tmp, 1);
+	}
+
+	return 0;
+}
+
+static int pmci_flash_bulk_read(struct intel_m10bmc *m10bmc, u8 *buf, u32 addr, u32 size)
+{
+	struct m10bmc_pmci_device *pmci = container_of(m10bmc, struct m10bmc_pmci_device, m10bmc);
+	u32 blk_size, offset = 0, val, full_read_count, read_count;
+	int ret;
+
+	while (size) {
+		blk_size = min_t(u32, size, M10BMC_PMCI_READ_BLOCK_SIZE);
+		full_read_count = blk_size / M10BMC_PMCI_FIFO_WORD_SIZE;
+
+		read_count = full_read_count;
+		if (full_read_count * M10BMC_PMCI_FIFO_WORD_SIZE < blk_size)
+			read_count++;
+
+		writel(addr + offset, pmci->base + M10BMC_PMCI_FLASH_ADDR);
+		writel(FIELD_PREP(M10BMC_PMCI_FLASH_READ_COUNT, read_count) |
+		       M10BMC_PMCI_FLASH_RD_MODE,
+		       pmci->base + M10BMC_PMCI_FLASH_CTRL);
+
+		ret = readl_poll_timeout((pmci->base + M10BMC_PMCI_FLASH_CTRL), val,
+					 !(val & M10BMC_PMCI_FLASH_BUSY),
+					 M10BMC_PMCI_FLASH_INT_US, M10BMC_PMCI_FLASH_TIMEOUT_US);
+		if (ret) {
+			dev_err(m10bmc->dev, "read timed out on reading flash 0x%xn", val);
+			return ret;
+		}
+
+		if (size < M10BMC_PMCI_FIFO_WORD_SIZE)
+			break;
+
+		pmci_read_fifo(pmci->base + M10BMC_PMCI_FLASH_FIFO,
+			       (u32 *)(buf + offset), full_read_count);
+
+		size -= blk_size;
+		offset += blk_size;
+
+		writel(0, pmci->base + M10BMC_PMCI_FLASH_CTRL);
+	}
+
+	/* Handle remainder (less than M10BMC_PMCI_FIFO_WORD_SIZE bytes) */
+	if (size) {
+		u32 tmp;
+
+		pmci_read_fifo(pmci->base + M10BMC_PMCI_FLASH_FIFO, &tmp, 1);
+		memcpy(buf + offset, &tmp, size);
+	}
+
+	return 0;
+}
+
+static int m10bmc_pmci_flash_write(struct intel_m10bmc *m10bmc, const u8 *buf, u32 offset, u32 size)
+{
+	return pmci_flash_bulk_write(m10bmc, buf + offset, size);
+}
+
+static const struct intel_m10bmc_flash_bulk_ops m10bmc_pmci_flash_bulk_ops = {
+	.read = pmci_flash_bulk_read,
+	.write = m10bmc_pmci_flash_write,
+};
+
 static const struct regmap_range m10bmc_pmci_regmap_range[] = {
 	regmap_reg_range(M10BMC_PMCI_SYS_BASE, M10BMC_PMCI_SYS_END),
 };
@@ -70,6 +212,7 @@ static struct regmap_config m10bmc_pmci_regmap_config = {
 
 static struct mfd_cell m10bmc_pmci_n6000_bmc_subdevs[] = {
 	{ .name = "n6000bmc-hwmon" },
+	{ .name = "n6000bmc-sec-update" },
 };
 
 static const struct m10bmc_csr_map m10bmc_pmci_csr_map = {
@@ -107,6 +250,8 @@ static int m10bmc_pmci_probe(struct dfl_device *ddev)
 	if (!pmci)
 		return -ENOMEM;
 
+	pmci->m10bmc.flash_bulk_ops = &m10bmc_pmci_flash_bulk_ops;
+
 	pmci->m10bmc.dev = dev;
 
 	pmci->base = devm_ioremap_resource(dev, &ddev->mmio_res);
diff --git a/include/linux/mfd/intel-m10-bmc.h b/include/linux/mfd/intel-m10-bmc.h
index d0497046de5f..ec4fac6a077a 100644
--- a/include/linux/mfd/intel-m10-bmc.h
+++ b/include/linux/mfd/intel-m10-bmc.h
@@ -107,16 +107,30 @@ struct intel_m10bmc_platform_info {
 	const struct m10bmc_csr_map *csr_map;
 };
 
+struct intel_m10bmc;
+
+/**
+ * struct intel_m10bmc_flash_bulk_ops - device specific operations for flash R/W
+ * @read: read a block of data from flash
+ * @write: write a block of data to flash
+ */
+struct intel_m10bmc_flash_bulk_ops {
+	int (*read)(struct intel_m10bmc *m10bmc, u8 *buf, u32 addr, u32 size);
+	int (*write)(struct intel_m10bmc *m10bmc, const u8 *buf, u32 offset, u32 size);
+};
+
 /**
  * struct intel_m10bmc - Intel MAX 10 BMC parent driver data structure
  * @dev: this device
  * @regmap: the regmap used to access registers by m10bmc itself
  * @info: the platform information for MAX10 BMC
+ * @flash_bulk_ops: optional device specific operations for flash R/W
  */
 struct intel_m10bmc {
 	struct device *dev;
 	struct regmap *regmap;
 	const struct intel_m10bmc_platform_info *info;
+	const struct intel_m10bmc_flash_bulk_ops *flash_bulk_ops;
 };
 
 /*
-- 
2.30.2