[PATCH 07/13] spi: intel-dg: implement spi access functions

[Alexander Usyskin <alexander.usyskin@intel.com>]

Implement spi_read(), spi_erase() and spi_write() functions.

CC: Lucas De Marchi <lucas.demarchi@intel.com>
CC: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Vitaly Lubart <vitaly.lubart@intel.com>
---
 drivers/spi/spi-intel-dg.c | 199 +++++++++++++++++++++++++++++++++++++
 1 file changed, 199 insertions(+)

diff --git a/drivers/spi/spi-intel-dg.c b/drivers/spi/spi-intel-dg.c
index 8ef9dccc9062..af65101456a4 100644
--- a/drivers/spi/spi-intel-dg.c
+++ b/drivers/spi/spi-intel-dg.c
@@ -3,13 +3,16 @@
  * Copyright(c) 2019-2024, Intel Corporation. All rights reserved.
  */
 
+#include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/intel_dg_spi_aux.h>
 #include <linux/io.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/string.h>
 #include <linux/slab.h>
+#include <linux/sizes.h>
 #include <linux/types.h>
 
 struct intel_dg_spi {
@@ -84,6 +87,33 @@ static inline u32 spi_read32(struct intel_dg_spi *spi, u32 address)
 	return ioread32(base + SPI_TRIGGER_REG);
 }
 
+static inline u64 spi_read64(struct intel_dg_spi *spi, u32 address)
+{
+	void __iomem *base = spi->base;
+
+	iowrite32(address, base + SPI_ADDRESS_REG);
+
+	return readq(base + SPI_TRIGGER_REG);
+}
+
+static void spi_write32(struct intel_dg_spi *spi, u32 address, u32 data)
+{
+	void __iomem *base = spi->base;
+
+	iowrite32(address, base + SPI_ADDRESS_REG);
+
+	iowrite32(data, base + SPI_TRIGGER_REG);
+}
+
+static void spi_write64(struct intel_dg_spi *spi, u32 address, u64 data)
+{
+	void __iomem *base = spi->base;
+
+	iowrite32(address, base + SPI_ADDRESS_REG);
+
+	writeq(data, base + SPI_TRIGGER_REG);
+}
+
 static int spi_get_access_map(struct intel_dg_spi *spi)
 {
 	u32 flmap1;
@@ -140,6 +170,175 @@ static int intel_dg_spi_is_valid(struct intel_dg_spi *spi)
 	return 0;
 }
 
+__maybe_unused
+static unsigned int spi_get_region(const struct intel_dg_spi *spi, loff_t from)
+{
+	unsigned int i;
+
+	for (i = 0; i < spi->nregions; i++) {
+		if ((spi->regions[i].offset + spi->regions[i].size - 1) > from &&
+		    spi->regions[i].offset <= from &&
+		    spi->regions[i].size != 0)
+			break;
+	}
+
+	return i;
+}
+
+static ssize_t spi_rewrite_partial(struct intel_dg_spi *spi, loff_t to,
+			       loff_t offset, size_t len, const u32 *newdata)
+{
+	u32 data = spi_read32(spi, to);
+
+	if (spi_error(spi))
+		return -EIO;
+
+	memcpy((u8 *)&data + offset, newdata, len);
+
+	spi_write32(spi, to, data);
+	if (spi_error(spi))
+		return -EIO;
+
+	return len;
+}
+
+__maybe_unused
+static ssize_t spi_write(struct intel_dg_spi *spi, u8 region,
+			 loff_t to, size_t len, const unsigned char *buf)
+{
+	size_t i;
+	size_t len8;
+	size_t len4;
+	size_t to4;
+	size_t to_shift;
+	size_t len_s = len;
+	ssize_t ret;
+
+	spi_set_region_id(spi, region);
+
+	to4 = ALIGN_DOWN(to, sizeof(u32));
+	to_shift = min(sizeof(u32) - ((size_t)to - to4), len);
+	if (to - to4) {
+		ret = spi_rewrite_partial(spi, to4, to - to4, to_shift,
+					  (uint32_t *)&buf[0]);
+		if (ret < 0)
+			return ret;
+
+		buf += to_shift;
+		to += to_shift;
+		len_s -= to_shift;
+	}
+
+	len8 = ALIGN_DOWN(len_s, sizeof(u64));
+	for (i = 0; i < len8; i += sizeof(u64)) {
+		u64 data;
+
+		memcpy(&data, &buf[i], sizeof(u64));
+		spi_write64(spi, to + i, data);
+		if (spi_error(spi))
+			return -EIO;
+	}
+
+	len4 = len_s - len8;
+	if (len4 >= sizeof(u32)) {
+		u32 data;
+
+		memcpy(&data, &buf[i], sizeof(u32));
+		spi_write32(spi, to + i, data);
+		if (spi_error(spi))
+			return -EIO;
+		i += sizeof(u32);
+		len4 -= sizeof(u32);
+	}
+
+	if (len4 > 0) {
+		ret = spi_rewrite_partial(spi, to + i, 0, len4,
+					  (uint32_t *)&buf[i]);
+		if (ret < 0)
+			return ret;
+	}
+
+	return len;
+}
+
+__maybe_unused
+static ssize_t spi_read(struct intel_dg_spi *spi, u8 region,
+			loff_t from, size_t len, unsigned char *buf)
+{
+	size_t i;
+	size_t len8;
+	size_t len4;
+	size_t from4;
+	size_t from_shift;
+	size_t len_s = len;
+
+	spi_set_region_id(spi, region);
+
+	from4 = ALIGN_DOWN(from, sizeof(u32));
+	from_shift = min(sizeof(u32) - ((size_t)from - from4), len);
+
+	if (from - from4) {
+		u32 data = spi_read32(spi, from4);
+
+		if (spi_error(spi))
+			return -EIO;
+		memcpy(&buf[0], (u8 *)&data + (from - from4), from_shift);
+		len_s -= from_shift;
+		buf += from_shift;
+		from += from_shift;
+	}
+
+	len8 = ALIGN_DOWN(len_s, sizeof(u64));
+	for (i = 0; i < len8; i += sizeof(u64)) {
+		u64 data = spi_read64(spi, from + i);
+
+		if (spi_error(spi))
+			return -EIO;
+
+		memcpy(&buf[i], &data, sizeof(data));
+	}
+
+	len4 = len_s - len8;
+	if (len4 >= sizeof(u32)) {
+		u32 data = spi_read32(spi, from + i);
+
+		if (spi_error(spi))
+			return -EIO;
+		memcpy(&buf[i], &data, sizeof(data));
+		i += sizeof(u32);
+		len4 -= sizeof(u32);
+	}
+
+	if (len4 > 0) {
+		u32 data = spi_read32(spi, from + i);
+
+		if (spi_error(spi))
+			return -EIO;
+		memcpy(&buf[i], &data, len4);
+	}
+
+	return len;
+}
+
+__maybe_unused
+static ssize_t
+spi_erase(struct intel_dg_spi *spi, u8 region, loff_t from, u64 len, u64 *fail_addr)
+{
+	u64 i;
+	const u32 block = 0x10;
+	void __iomem *base = spi->base;
+
+	for (i = 0; i < len; i += SZ_4K) {
+		iowrite32(from + i, base + SPI_ADDRESS_REG);
+		iowrite32(region << 24 | block, base + SPI_ERASE_REG);
+		/* Since the writes are via sguint
+		 * we cannot do back to back erases.
+		 */
+		msleep(50);
+	}
+	return len;
+}
+
 static int intel_dg_spi_init(struct intel_dg_spi *spi, struct device *device)
 {
 	int ret;
-- 
2.34.1