diff options
Diffstat (limited to 'drivers/spi/zynq_qspi.c')
| -rw-r--r-- | drivers/spi/zynq_qspi.c | 84 |
1 files changed, 64 insertions, 20 deletions
diff --git a/drivers/spi/zynq_qspi.c b/drivers/spi/zynq_qspi.c index 3f39ef0..f2eddec 100644 --- a/drivers/spi/zynq_qspi.c +++ b/drivers/spi/zynq_qspi.c @@ -6,8 +6,10 @@ * Xilinx Zynq Quad-SPI(QSPI) controller driver (master mode only) */ +#include <clk.h> #include <common.h> #include <dm.h> +#include <dm/device_compat.h> #include <log.h> #include <malloc.h> #include <spi.h> @@ -105,17 +107,29 @@ static int zynq_qspi_ofdata_to_platdata(struct udevice *bus) plat->regs = (struct zynq_qspi_regs *)fdtdec_get_addr(blob, node, "reg"); - /* FIXME: Use 166MHz as a suitable default */ - plat->frequency = fdtdec_get_int(blob, node, "spi-max-frequency", - 166666666); - plat->speed_hz = plat->frequency / 2; - - debug("%s: regs=%p max-frequency=%d\n", __func__, - plat->regs, plat->frequency); - return 0; } +/** + * zynq_qspi_init_hw - Initialize the hardware + * @priv: Pointer to the zynq_qspi_priv structure + * + * The default settings of the QSPI controller's configurable parameters on + * reset are + * - Master mode + * - Baud rate divisor is set to 2 + * - Threshold value for TX FIFO not full interrupt is set to 1 + * - Flash memory interface mode enabled + * - Size of the word to be transferred as 8 bit + * This function performs the following actions + * - Disable and clear all the interrupts + * - Enable manual slave select + * - Enable auto start + * - Deselect all the chip select lines + * - Set the size of the word to be transferred as 32 bit + * - Set the little endian mode of TX FIFO and + * - Enable the QSPI controller + */ static void zynq_qspi_init_hw(struct zynq_qspi_priv *priv) { struct zynq_qspi_regs *regs = priv->regs; @@ -159,19 +173,45 @@ static int zynq_qspi_probe(struct udevice *bus) { struct zynq_qspi_platdata *plat = dev_get_platdata(bus); struct zynq_qspi_priv *priv = dev_get_priv(bus); + struct clk clk; + unsigned long clock; + int ret; priv->regs = plat->regs; priv->fifo_depth = ZYNQ_QSPI_FIFO_DEPTH; + ret = clk_get_by_name(bus, "ref_clk", &clk); + if (ret < 0) { + dev_err(bus, "failed to get clock\n"); + return ret; + } + + clock = clk_get_rate(&clk); + if (IS_ERR_VALUE(clock)) { + dev_err(bus, "failed to get rate\n"); + return clock; + } + + ret = clk_enable(&clk); + if (ret && ret != -ENOSYS) { + dev_err(bus, "failed to enable clock\n"); + return ret; + } + /* init the zynq spi hw */ zynq_qspi_init_hw(priv); + plat->frequency = clock; + plat->speed_hz = plat->frequency / 2; + + debug("%s: max-frequency=%d\n", __func__, plat->speed_hz); + return 0; } -/* +/** * zynq_qspi_read_data - Copy data to RX buffer - * @zqspi: Pointer to the zynq_qspi structure + * @priv: Pointer to the zynq_qspi_priv structure * @data: The 32 bit variable where data is stored * @size: Number of bytes to be copied from data to RX buffer */ @@ -214,9 +254,9 @@ static void zynq_qspi_read_data(struct zynq_qspi_priv *priv, u32 data, u8 size) priv->bytes_to_receive = 0; } -/* +/** * zynq_qspi_write_data - Copy data from TX buffer - * @zqspi: Pointer to the zynq_qspi structure + * @priv: Pointer to the zynq_qspi_priv structure * @data: Pointer to the 32 bit variable where data is to be copied * @size: Number of bytes to be copied from TX buffer to data */ @@ -263,6 +303,11 @@ static void zynq_qspi_write_data(struct zynq_qspi_priv *priv, priv->bytes_to_transfer = 0; } +/** + * zynq_qspi_chipselect - Select or deselect the chip select line + * @priv: Pointer to the zynq_qspi_priv structure + * @is_on: Select(1) or deselect (0) the chip select line + */ static void zynq_qspi_chipselect(struct zynq_qspi_priv *priv, int is_on) { u32 confr; @@ -282,9 +327,10 @@ static void zynq_qspi_chipselect(struct zynq_qspi_priv *priv, int is_on) writel(confr, ®s->cr); } -/* +/** * zynq_qspi_fill_tx_fifo - Fills the TX FIFO with as many bytes as possible - * @zqspi: Pointer to the zynq_qspi structure + * @priv: Pointer to the zynq_qspi_priv structure + * @size: Number of bytes to be copied to fifo */ static void zynq_qspi_fill_tx_fifo(struct zynq_qspi_priv *priv, u32 size) { @@ -322,9 +368,9 @@ static void zynq_qspi_fill_tx_fifo(struct zynq_qspi_priv *priv, u32 size) } } -/* +/** * zynq_qspi_irq_poll - Interrupt service routine of the QSPI controller - * @zqspi: Pointer to the zynq_qspi structure + * @priv: Pointer to the zynq_qspi structure * * This function handles TX empty and Mode Fault interrupts only. * On TX empty interrupt this function reads the received data from RX FIFO and @@ -410,11 +456,9 @@ static int zynq_qspi_irq_poll(struct zynq_qspi_priv *priv) return 0; } -/* +/** * zynq_qspi_start_transfer - Initiates the QSPI transfer - * @qspi: Pointer to the spi_device structure - * @transfer: Pointer to the spi_transfer structure which provide information - * about next transfer parameters + * @priv: Pointer to the zynq_qspi_priv structure * * This function fills the TX FIFO, starts the QSPI transfer, and waits for the * transfer to be completed. |