Add support for configuring the speed of the bus per
device as the fastest clock that is less or equal to
the device max_speed_hz
Signed-off-by: Lucas Tanure <[email protected]>
---
drivers/spi/spi-amd.c | 105 +++++++++++++++++++++++++++++++++++++++++-
1 file changed, 104 insertions(+), 1 deletion(-)
diff --git a/drivers/spi/spi-amd.c b/drivers/spi/spi-amd.c
index 788a5c42d811..0dde1ce757f2 100644
--- a/drivers/spi/spi-amd.c
+++ b/drivers/spi/spi-amd.c
@@ -19,7 +19,11 @@
#define AMD_SPI_EXEC_CMD BIT(16)
#define AMD_SPI_FIFO_CLEAR BIT(20)
#define AMD_SPI_BUSY BIT(31)
-#define AMD_SPI_ENABLE_REG 0x20
+#define AMD_SPI_ENA_REG 0x20
+#define AMD_SPI_ALT_SPD_SHIFT 20
+#define AMD_SPI_ALT_SPD_MASK GENMASK(23, AMD_SPI_ALT_SPD_SHIFT)
+#define AMD_SPI_SPI100_SHIFT 0
+#define AMD_SPI_SPI100_MASK GENMASK(AMD_SPI_SPI100_SHIFT, AMD_SPI_SPI100_SHIFT)
#define AMD_SPI_DUMMY_CYCL_REG 0x32
#define AMD_SPI_OPCODE_REG 0x45
@@ -34,6 +38,11 @@
#define AMD_SPI_TX_COUNT_REG 0x48
#define AMD_SPI_RX_COUNT_REG 0x4B
#define AMD_SPI_STATUS_REG 0x4C
+#define AMD_SPI_SPEED_REG 0x6C
+#define AMD_SPI_SPD7_SHIFT 8
+#define AMD_SPI_SPD7_MASK GENMASK(13, AMD_SPI_SPD7_SHIFT)
+#define AMD_SPI_SPD6_SHIFT 0
+#define AMD_SPI_SPD6_MASK GENMASK(5, AMD_SPI_SPD6_SHIFT)
#define AMD_SPI_FIFO_SIZE 70
#define AMD_SPI_MEM_SIZE 200
@@ -42,6 +51,33 @@
#define AMD_SPI_XFER_TX 1
#define AMD_SPI_XFER_RX 2
+#define AMD_SPI_MAX_HZ 100000000
+#define AMD_SPI_MIN_HZ 800000
+
+static bool speed_dev;
+module_param(speed_dev, bool, 0644);
+
+enum amd_spi_speed {
+ F_66_66MHz,
+ F_33_33MHz,
+ F_22_22MHz,
+ F_16_66MHz,
+ F_100MHz,
+ F_800KHz,
+ SPI_SPD6,
+ SPI_SPD7,
+ F_50MHz = 0x4,
+ F_4MHz = 0x32,
+ F_3_17MHz = 0x3F
+};
+
+struct amd_spi_freq {
+ u32 speed_hz;
+ u32 ena;
+ u32 spd7;
+ bool use_spi100_eng;
+};
+
struct amd_spi {
void __iomem *io_remap_addr;
unsigned long io_base_addr;
@@ -50,6 +86,7 @@ struct amd_spi {
const struct amd_spi_devtype_data *devtype_data;
struct spi_device *spi_dev;
struct spi_master *master;
+ u32 speed_hz;
};
struct amd_spi_devtype_data {
@@ -191,11 +228,63 @@ static int amd_spi_execute_opcode_v2(struct amd_spi *amd_spi)
return 0;
}
+static const struct amd_spi_freq amd_spi_freq[] = {
+ { AMD_SPI_MAX_HZ, F_100MHz, 0, true},
+ { 66660000, F_66_66MHz, 0, false},
+ { 50000000, SPI_SPD7, F_50MHz, false},
+ { 33330000, F_33_33MHz, 0, false},
+ { 22220000, F_22_22MHz, 0, false},
+ { 16660000, F_16_66MHz, 0, false},
+ { 4000000, SPI_SPD7, F_4MHz, false},
+ { 3170000, SPI_SPD7, F_3_17MHz, false},
+ { AMD_SPI_MIN_HZ, F_800KHz, 0, false},
+};
+
+static int amd_set_spi_freq(struct amd_spi *amd_spi, u32 speed_hz)
+{
+ int i;
+ bool use_spi100_eng = false;
+ u32 spd7 = 0, ena;
+
+ if (speed_hz == amd_spi->speed_hz)
+ return 0;
+
+ if (speed_hz < AMD_SPI_MIN_HZ)
+ return -EINVAL;
+
+ for (i = 0; i < ARRAY_SIZE(amd_spi_freq); i++) {
+ if (speed_hz >= amd_spi_freq[i].speed_hz) {
+ if (amd_spi->speed_hz == amd_spi_freq[i].speed_hz)
+ return 0;
+ amd_spi->speed_hz = amd_spi_freq[i].speed_hz;
+
+ use_spi100_eng = amd_spi_freq[i].use_spi100_eng;
+ spd7 = (amd_spi_freq[i].spd7 << AMD_SPI_SPD7_SHIFT) & AMD_SPI_SPD7_MASK;
+ ena = (amd_spi_freq[i].ena << AMD_SPI_ALT_SPD_SHIFT) & AMD_SPI_ALT_SPD_MASK;
+
+ amd_spi_setclear_reg32(amd_spi, AMD_SPI_ENA_REG, ena, AMD_SPI_ALT_SPD_MASK);
+ break;
+ }
+ }
+
+ if (spd7)
+ amd_spi_setclear_reg32(amd_spi, AMD_SPI_SPEED_REG, spd7, AMD_SPI_SPD7_MASK);
+
+ if (use_spi100_eng)
+ amd_spi_setclear_reg32(amd_spi, AMD_SPI_ENA_REG,
+ AMD_SPI_SPI100_MASK < AMD_SPI_SPI100_SHIFT,
+ AMD_SPI_SPI100_MASK);
+
+ return 0;
+}
+
static int amd_spi_master_setup(struct spi_device *spi)
{
struct amd_spi *amd_spi = spi_master_get_devdata(spi->master);
amd_spi_clear_fifo_ptr(amd_spi);
+ if (speed_dev)
+ amd_set_spi_freq(amd_spi, spi->max_speed_hz);
return 0;
}
@@ -322,6 +411,17 @@ static int amd_spi_transfer_one_message(struct spi_controller *ctrl, struct spi_
return ret;
}
+static int amd_spi_prepare_message(struct spi_controller *ctlr, struct spi_message *msg)
+{
+ struct amd_spi *amd_spi = spi_controller_get_devdata(ctlr);
+ struct spi_device *spi = msg->spi;
+
+ if (speed_dev)
+ amd_set_spi_freq(amd_spi, spi->max_speed_hz);
+
+ return 0;
+}
+
static size_t amd_spi_max_transfer_size(struct spi_device *spi)
{
return AMD_SPI_FIFO_SIZE;
@@ -360,10 +460,13 @@ static int amd_spi_probe(struct platform_device *pdev)
master->bus_num = 0;
master->num_chipselect = 4;
master->mode_bits = 0;
+ master->max_speed_hz = AMD_SPI_MAX_HZ;
+ master->min_speed_hz = AMD_SPI_MIN_HZ;
master->flags = SPI_CONTROLLER_HALF_DUPLEX | SPI_CONTROLLER_NO_TX_RX_CS;
master->setup = amd_spi_master_setup;
master->max_transfer_size = amd_spi_max_transfer_size;
master->max_message_size = amd_spi_max_transfer_size;
+ master->prepare_message = amd_spi_prepare_message;
master->transfer_one_message = amd_spi_transfer_one_message;
INIT_LIST_HEAD(&amd_spi->rbuf_head);
--
2.33.0