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Subject[PATCH] spi: spi_amd: Add support for SPI MEM framework
Date
Add support to the SPI controller driver to use SPI MEM framework.
SPI subsystem utilizing the SPI memory operations allows to re-use
SPI controller drivers for both SPI NOR devices, regular SPI devices
as well as SPI NAND devices.

Add below functions of spi_mem_ops to support SPI MEM framework
- exec-op(): to execute the memory operations.
- supports_op(): to check if the memory operation is supported.
- adjust_op_size(): to split data transfers so that they don’t exceed the
max transfer size supported by the controller.

Suggested-by: Sudheesh Mavila <sudheesh.mavila@amd.com>
Co-developed-by: Krishnamoorthi M <krishnamoorthi.m@amd.com>
Signed-off-by: Krishnamoorthi M <krishnamoorthi.m@amd.com>
Co-developed-by: Akshata MukundShetty <akshata.mukundshetty@amd.com>
Signed-off-by: Akshata MukundShetty <akshata.mukundshetty@amd.com>
Signed-off-by: Raju Rangoju <Raju.Rangoju@amd.com>
---
drivers/spi/spi-amd.c | 112 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 112 insertions(+)

diff --git a/drivers/spi/spi-amd.c b/drivers/spi/spi-amd.c
index 5d9b246b6963..2245ad54b03a 100644
--- a/drivers/spi/spi-amd.c
+++ b/drivers/spi/spi-amd.c
@@ -13,6 +13,7 @@
#include <linux/delay.h>
#include <linux/spi/spi.h>
#include <linux/iopoll.h>
+#include <linux/spi/spi-mem.h>

#define AMD_SPI_CTRL0_REG 0x00
#define AMD_SPI_EXEC_CMD BIT(16)
@@ -35,6 +36,7 @@

#define AMD_SPI_FIFO_SIZE 70
#define AMD_SPI_MEM_SIZE 200
+#define AMD_SPI_MAX_DATA 64

#define AMD_SPI_ENA_REG 0x20
#define AMD_SPI_ALT_SPD_SHIFT 20
@@ -358,6 +360,115 @@ static inline int amd_spi_fifo_xfer(struct amd_spi *amd_spi,
return message->status;
}

+static bool amd_spi_supports_op(struct spi_mem *mem,
+ const struct spi_mem_op *op)
+{
+ /* bus width is number of IO lines used to transmit */
+ if (op->cmd.buswidth > 1 || op->addr.buswidth > 1 ||
+ op->data.buswidth > 1 || op->data.nbytes > AMD_SPI_MAX_DATA)
+ return false;
+
+ return spi_mem_default_supports_op(mem, op);
+}
+
+static int amd_spi_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
+{
+ op->data.nbytes = clamp_val(op->data.nbytes, 0, AMD_SPI_MAX_DATA);
+ return 0;
+}
+
+static void amd_spi_set_addr(struct amd_spi *amd_spi,
+ const struct spi_mem_op *op)
+{
+ u8 nbytes = op->addr.nbytes;
+ u64 addr_val = op->addr.val;
+ int base_addr, i;
+
+ base_addr = AMD_SPI_FIFO_BASE + nbytes;
+
+ for (i = 0; i < nbytes; i++) {
+ amd_spi_writereg8(amd_spi, base_addr - i - 1, addr_val &
+ GENMASK(7, 0));
+ addr_val >>= 8;
+ }
+}
+
+static void amd_spi_mem_data_out(struct amd_spi *amd_spi,
+ const struct spi_mem_op *op)
+{
+ int base_addr = AMD_SPI_FIFO_BASE + op->addr.nbytes;
+ u8 *buf = (u8 *)op->data.buf.out;
+ u32 nbytes = op->data.nbytes;
+ int i;
+
+ amd_spi_set_opcode(amd_spi, op->cmd.opcode);
+ amd_spi_set_addr(amd_spi, op);
+
+ for (i = 0; i < nbytes; i++)
+ amd_spi_writereg8(amd_spi, (base_addr + i), buf[i]);
+
+ amd_spi_set_tx_count(amd_spi, op->addr.nbytes + op->data.nbytes);
+ amd_spi_set_rx_count(amd_spi, 0);
+ amd_spi_clear_fifo_ptr(amd_spi);
+ amd_spi_execute_opcode(amd_spi);
+}
+
+static void amd_spi_mem_data_in(struct amd_spi *amd_spi,
+ const struct spi_mem_op *op)
+{
+ int offset = (op->addr.nbytes == 0) ? 0 : 1;
+ u8 *buf = (u8 *)op->data.buf.in;
+ u32 nbytes = op->data.nbytes;
+ int base_addr, i;
+
+ base_addr = AMD_SPI_FIFO_BASE + op->addr.nbytes + offset;
+
+ amd_spi_set_opcode(amd_spi, op->cmd.opcode);
+ amd_spi_set_addr(amd_spi, op);
+ amd_spi_set_tx_count(amd_spi, op->addr.nbytes);
+ amd_spi_set_rx_count(amd_spi, op->data.nbytes + 1);
+ amd_spi_clear_fifo_ptr(amd_spi);
+ amd_spi_execute_opcode(amd_spi);
+ amd_spi_busy_wait(amd_spi);
+
+ for (i = 0; i < nbytes; i++)
+ buf[i] = amd_spi_readreg8(amd_spi, base_addr + i);
+}
+
+static int amd_spi_exec_mem_op(struct spi_mem *mem,
+ const struct spi_mem_op *op)
+{
+ struct amd_spi *amd_spi;
+ int ret;
+
+ amd_spi = spi_controller_get_devdata(mem->spi->controller);
+
+ ret = amd_set_spi_freq(amd_spi, mem->spi->max_speed_hz);
+ if (ret)
+ return ret;
+
+ switch (op->data.dir) {
+ case SPI_MEM_DATA_IN:
+ amd_spi_mem_data_in(amd_spi, op);
+ break;
+ case SPI_MEM_DATA_OUT:
+ fallthrough;
+ case SPI_MEM_NO_DATA:
+ amd_spi_mem_data_out(amd_spi, op);
+ break;
+ default:
+ ret = -EOPNOTSUPP;
+ }
+
+ return ret;
+}
+
+static const struct spi_controller_mem_ops amd_spi_mem_ops = {
+ .exec_op = amd_spi_exec_mem_op,
+ .adjust_op_size = amd_spi_adjust_op_size,
+ .supports_op = amd_spi_supports_op,
+};
+
static int amd_spi_host_transfer(struct spi_controller *host,
struct spi_message *msg)
{
@@ -409,6 +520,7 @@ static int amd_spi_probe(struct platform_device *pdev)
host->min_speed_hz = AMD_SPI_MIN_HZ;
host->setup = amd_spi_host_setup;
host->transfer_one_message = amd_spi_host_transfer;
+ host->mem_ops = &amd_spi_mem_ops;
host->max_transfer_size = amd_spi_max_transfer_size;
host->max_message_size = amd_spi_max_transfer_size;

--
2.34.1

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