spi: spi_amd: Add support for SPI MEM framework

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>
Link: https://msgid.link/r/20240229134544.3461757-1-Raju.Rangoju@amd.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-amd.c b/drivers/spi/spi-amd.c
index 5d9b246b69634006601f81a72489e637a25f1071..2245ad54b03aa3747bde07e04f6d178f815a913d 100644 (file)
--- 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 @@ fin_msg:
        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;