diff options
Diffstat (limited to 'drivers/spi/spi-zynq-qspi.c')
| -rw-r--r-- | drivers/spi/spi-zynq-qspi.c | 84 |
1 files changed, 50 insertions, 34 deletions
diff --git a/drivers/spi/spi-zynq-qspi.c b/drivers/spi/spi-zynq-qspi.c index 5cf6993ddce5..17641157354d 100644 --- a/drivers/spi/spi-zynq-qspi.c +++ b/drivers/spi/spi-zynq-qspi.c @@ -7,7 +7,6 @@ #include <linux/clk.h> #include <linux/delay.h> -#include <linux/gpio.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/module.h> @@ -51,7 +50,6 @@ #define ZYNQ_QSPI_CONFIG_BDRATE_MASK GENMASK(5, 3) /* Baud Rate Mask */ #define ZYNQ_QSPI_CONFIG_CPHA_MASK BIT(2) /* Clock Phase Control */ #define ZYNQ_QSPI_CONFIG_CPOL_MASK BIT(1) /* Clock Polarity Control */ -#define ZYNQ_QSPI_CONFIG_SSCTRL_MASK BIT(10) /* Slave Select Mask */ #define ZYNQ_QSPI_CONFIG_FWIDTH_MASK GENMASK(7, 6) /* FIFO width */ #define ZYNQ_QSPI_CONFIG_MSTREN_MASK BIT(0) /* Master Mode */ @@ -61,9 +59,9 @@ * These are the values used in the calculation of baud rate divisor and * setting the slave select. */ -#define ZYNQ_QSPI_BAUD_DIV_MAX GENMASK(2, 0) /* Baud rate maximum */ -#define ZYNQ_QSPI_BAUD_DIV_SHIFT 3 /* Baud rate divisor shift in CR */ -#define ZYNQ_QSPI_SS_SHIFT 10 /* Slave Select field shift in CR */ +#define ZYNQ_QSPI_CONFIG_BAUD_DIV_MAX GENMASK(2, 0) /* Baud rate maximum */ +#define ZYNQ_QSPI_CONFIG_BAUD_DIV_SHIFT 3 /* Baud rate divisor shift */ +#define ZYNQ_QSPI_CONFIG_PCS BIT(10) /* Peripheral Chip Select */ /* * QSPI Interrupt Registers bit Masks @@ -99,9 +97,9 @@ * It is named Linear Configuration but it controls other modes when not in * linear mode also. */ -#define ZYNQ_QSPI_LCFG_TWO_MEM_MASK BIT(30) /* LQSPI Two memories Mask */ -#define ZYNQ_QSPI_LCFG_SEP_BUS_MASK BIT(29) /* LQSPI Separate bus Mask */ -#define ZYNQ_QSPI_LCFG_U_PAGE_MASK BIT(28) /* LQSPI Upper Page Mask */ +#define ZYNQ_QSPI_LCFG_TWO_MEM BIT(30) /* LQSPI Two memories */ +#define ZYNQ_QSPI_LCFG_SEP_BUS BIT(29) /* LQSPI Separate bus */ +#define ZYNQ_QSPI_LCFG_U_PAGE BIT(28) /* LQSPI Upper Page */ #define ZYNQ_QSPI_LCFG_DUMMY_SHIFT 8 @@ -116,8 +114,8 @@ */ #define ZYNQ_QSPI_MODEBITS (SPI_CPOL | SPI_CPHA) -/* Default number of chip selects */ -#define ZYNQ_QSPI_DEFAULT_NUM_CS 1 +/* Maximum number of chip selects */ +#define ZYNQ_QSPI_MAX_NUM_CS 2 /** * struct zynq_qspi - Defines qspi driver instance @@ -161,6 +159,7 @@ static inline void zynq_qspi_write(struct zynq_qspi *xqspi, u32 offset, /** * zynq_qspi_init_hw - Initialize the hardware * @xqspi: Pointer to the zynq_qspi structure + * @num_cs: Number of connected CS (to enable dual memories if needed) * * The default settings of the QSPI controller's configurable parameters on * reset are @@ -178,7 +177,7 @@ static inline void zynq_qspi_write(struct zynq_qspi *xqspi, u32 offset, * - Set the little endian mode of TX FIFO and * - Enable the QSPI controller */ -static void zynq_qspi_init_hw(struct zynq_qspi *xqspi) +static void zynq_qspi_init_hw(struct zynq_qspi *xqspi, unsigned int num_cs) { u32 config_reg; @@ -186,7 +185,12 @@ static void zynq_qspi_init_hw(struct zynq_qspi *xqspi) zynq_qspi_write(xqspi, ZYNQ_QSPI_IDIS_OFFSET, ZYNQ_QSPI_IXR_ALL_MASK); /* Disable linear mode as the boot loader may have used it */ - zynq_qspi_write(xqspi, ZYNQ_QSPI_LINEAR_CFG_OFFSET, 0); + config_reg = 0; + /* At the same time, enable dual mode if more than 1 CS is available */ + if (num_cs > 1) + config_reg |= ZYNQ_QSPI_LCFG_TWO_MEM; + + zynq_qspi_write(xqspi, ZYNQ_QSPI_LINEAR_CFG_OFFSET, config_reg); /* Clear the RX FIFO */ while (zynq_qspi_read(xqspi, ZYNQ_QSPI_STATUS_OFFSET) & @@ -284,21 +288,28 @@ static void zynq_qspi_txfifo_op(struct zynq_qspi *xqspi, unsigned int size) */ static void zynq_qspi_chipselect(struct spi_device *spi, bool assert) { - struct spi_controller *ctrl = spi->master; - struct zynq_qspi *xqspi = spi_controller_get_devdata(ctrl); + struct spi_controller *ctlr = spi->master; + struct zynq_qspi *xqspi = spi_controller_get_devdata(ctlr); u32 config_reg; - config_reg = zynq_qspi_read(xqspi, ZYNQ_QSPI_CONFIG_OFFSET); - if (assert) { - /* Select the slave */ - config_reg &= ~ZYNQ_QSPI_CONFIG_SSCTRL_MASK; - config_reg |= (((~(BIT(spi->chip_select))) << - ZYNQ_QSPI_SS_SHIFT) & - ZYNQ_QSPI_CONFIG_SSCTRL_MASK); - } else { - config_reg |= ZYNQ_QSPI_CONFIG_SSCTRL_MASK; + /* Select the lower (CS0) or upper (CS1) memory */ + if (ctlr->num_chipselect > 1) { + config_reg = zynq_qspi_read(xqspi, ZYNQ_QSPI_LINEAR_CFG_OFFSET); + if (!spi->chip_select) + config_reg &= ~ZYNQ_QSPI_LCFG_U_PAGE; + else + config_reg |= ZYNQ_QSPI_LCFG_U_PAGE; + + zynq_qspi_write(xqspi, ZYNQ_QSPI_LINEAR_CFG_OFFSET, config_reg); } + /* Ground the line to assert the CS */ + config_reg = zynq_qspi_read(xqspi, ZYNQ_QSPI_CONFIG_OFFSET); + if (assert) + config_reg &= ~ZYNQ_QSPI_CONFIG_PCS; + else + config_reg |= ZYNQ_QSPI_CONFIG_PCS; + zynq_qspi_write(xqspi, ZYNQ_QSPI_CONFIG_OFFSET, config_reg); } @@ -332,7 +343,7 @@ static int zynq_qspi_config_op(struct zynq_qspi *xqspi, struct spi_device *spi) * ---------------- * 111 - divide by 256 */ - while ((baud_rate_val < ZYNQ_QSPI_BAUD_DIV_MAX) && + while ((baud_rate_val < ZYNQ_QSPI_CONFIG_BAUD_DIV_MAX) && (clk_get_rate(xqspi->refclk) / (2 << baud_rate_val)) > spi->max_speed_hz) baud_rate_val++; @@ -348,7 +359,7 @@ static int zynq_qspi_config_op(struct zynq_qspi *xqspi, struct spi_device *spi) config_reg |= ZYNQ_QSPI_CONFIG_CPOL_MASK; config_reg &= ~ZYNQ_QSPI_CONFIG_BDRATE_MASK; - config_reg |= (baud_rate_val << ZYNQ_QSPI_BAUD_DIV_SHIFT); + config_reg |= (baud_rate_val << ZYNQ_QSPI_CONFIG_BAUD_DIV_SHIFT); zynq_qspi_write(xqspi, ZYNQ_QSPI_CONFIG_OFFSET, config_reg); return 0; @@ -365,10 +376,10 @@ static int zynq_qspi_config_op(struct zynq_qspi *xqspi, struct spi_device *spi) */ static int zynq_qspi_setup_op(struct spi_device *spi) { - struct spi_controller *ctrl = spi->master; - struct zynq_qspi *qspi = spi_controller_get_devdata(ctrl); + struct spi_controller *ctlr = spi->master; + struct zynq_qspi *qspi = spi_controller_get_devdata(ctlr); - if (ctrl->busy) + if (ctlr->busy) return -EBUSY; clk_enable(qspi->refclk); @@ -663,9 +674,6 @@ static int zynq_qspi_probe(struct platform_device *pdev) goto clk_dis_pclk; } - /* QSPI controller initializations */ - zynq_qspi_init_hw(xqspi); - xqspi->irq = platform_get_irq(pdev, 0); if (xqspi->irq <= 0) { ret = -ENXIO; @@ -681,10 +689,14 @@ static int zynq_qspi_probe(struct platform_device *pdev) ret = of_property_read_u32(np, "num-cs", &num_cs); - if (ret < 0) - ctlr->num_chipselect = ZYNQ_QSPI_DEFAULT_NUM_CS; - else + if (ret < 0) { + ctlr->num_chipselect = 1; + } else if (num_cs > ZYNQ_QSPI_MAX_NUM_CS) { + dev_err(&pdev->dev, "only 2 chip selects are available\n"); + goto remove_master; + } else { ctlr->num_chipselect = num_cs; + } ctlr->mode_bits = SPI_RX_DUAL | SPI_RX_QUAD | SPI_TX_DUAL | SPI_TX_QUAD; @@ -692,6 +704,10 @@ static int zynq_qspi_probe(struct platform_device *pdev) ctlr->setup = zynq_qspi_setup_op; ctlr->max_speed_hz = clk_get_rate(xqspi->refclk) / 2; ctlr->dev.of_node = np; + + /* QSPI controller initializations */ + zynq_qspi_init_hw(xqspi, ctlr->num_chipselect); + ret = devm_spi_register_controller(&pdev->dev, ctlr); if (ret) { dev_err(&pdev->dev, "spi_register_master failed\n"); |