diff options
Diffstat (limited to 'drivers/spi/spi-cadence.c')
| -rw-r--r-- | drivers/spi/spi-cadence.c | 798 |
1 files changed, 798 insertions, 0 deletions
diff --git a/drivers/spi/spi-cadence.c b/drivers/spi/spi-cadence.c new file mode 100644 index 000000000..91f83683c --- /dev/null +++ b/drivers/spi/spi-cadence.c @@ -0,0 +1,798 @@ +/* + * Cadence SPI controller driver (master mode only) + * + * Copyright (C) 2008 - 2014 Xilinx, Inc. + * + * based on Blackfin On-Chip SPI Driver (spi_bfin5xx.c) + * + * This program is free software; you can redistribute it and/or modify it under + * the terms of the GNU General Public License version 2 as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + */ + +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/gpio.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of_irq.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/spi/spi.h> + +/* Name of this driver */ +#define CDNS_SPI_NAME "cdns-spi" + +/* Register offset definitions */ +#define CDNS_SPI_CR 0x00 /* Configuration Register, RW */ +#define CDNS_SPI_ISR 0x04 /* Interrupt Status Register, RO */ +#define CDNS_SPI_IER 0x08 /* Interrupt Enable Register, WO */ +#define CDNS_SPI_IDR 0x0c /* Interrupt Disable Register, WO */ +#define CDNS_SPI_IMR 0x10 /* Interrupt Enabled Mask Register, RO */ +#define CDNS_SPI_ER 0x14 /* Enable/Disable Register, RW */ +#define CDNS_SPI_DR 0x18 /* Delay Register, RW */ +#define CDNS_SPI_TXD 0x1C /* Data Transmit Register, WO */ +#define CDNS_SPI_RXD 0x20 /* Data Receive Register, RO */ +#define CDNS_SPI_SICR 0x24 /* Slave Idle Count Register, RW */ +#define CDNS_SPI_THLD 0x28 /* Transmit FIFO Watermark Register,RW */ + +#define SPI_AUTOSUSPEND_TIMEOUT 3000 +/* + * SPI Configuration Register bit Masks + * + * This register contains various control bits that affect the operation + * of the SPI controller + */ +#define CDNS_SPI_CR_MANSTRT 0x00010000 /* Manual TX Start */ +#define CDNS_SPI_CR_CPHA 0x00000004 /* Clock Phase Control */ +#define CDNS_SPI_CR_CPOL 0x00000002 /* Clock Polarity Control */ +#define CDNS_SPI_CR_SSCTRL 0x00003C00 /* Slave Select Mask */ +#define CDNS_SPI_CR_PERI_SEL 0x00000200 /* Peripheral Select Decode */ +#define CDNS_SPI_CR_BAUD_DIV 0x00000038 /* Baud Rate Divisor Mask */ +#define CDNS_SPI_CR_MSTREN 0x00000001 /* Master Enable Mask */ +#define CDNS_SPI_CR_MANSTRTEN 0x00008000 /* Manual TX Enable Mask */ +#define CDNS_SPI_CR_SSFORCE 0x00004000 /* Manual SS Enable Mask */ +#define CDNS_SPI_CR_BAUD_DIV_4 0x00000008 /* Default Baud Div Mask */ +#define CDNS_SPI_CR_DEFAULT (CDNS_SPI_CR_MSTREN | \ + CDNS_SPI_CR_SSCTRL | \ + CDNS_SPI_CR_SSFORCE | \ + CDNS_SPI_CR_BAUD_DIV_4) + +/* + * SPI Configuration Register - Baud rate and slave select + * + * These are the values used in the calculation of baud rate divisor and + * setting the slave select. + */ + +#define CDNS_SPI_BAUD_DIV_MAX 7 /* Baud rate divisor maximum */ +#define CDNS_SPI_BAUD_DIV_MIN 1 /* Baud rate divisor minimum */ +#define CDNS_SPI_BAUD_DIV_SHIFT 3 /* Baud rate divisor shift in CR */ +#define CDNS_SPI_SS_SHIFT 10 /* Slave Select field shift in CR */ +#define CDNS_SPI_SS0 0x1 /* Slave Select zero */ + +/* + * SPI Interrupt Registers bit Masks + * + * All the four interrupt registers (Status/Mask/Enable/Disable) have the same + * bit definitions. + */ +#define CDNS_SPI_IXR_TXOW 0x00000004 /* SPI TX FIFO Overwater */ +#define CDNS_SPI_IXR_MODF 0x00000002 /* SPI Mode Fault */ +#define CDNS_SPI_IXR_RXNEMTY 0x00000010 /* SPI RX FIFO Not Empty */ +#define CDNS_SPI_IXR_DEFAULT (CDNS_SPI_IXR_TXOW | \ + CDNS_SPI_IXR_MODF) +#define CDNS_SPI_IXR_TXFULL 0x00000008 /* SPI TX Full */ +#define CDNS_SPI_IXR_ALL 0x0000007F /* SPI all interrupts */ + +/* + * SPI Enable Register bit Masks + * + * This register is used to enable or disable the SPI controller + */ +#define CDNS_SPI_ER_ENABLE 0x00000001 /* SPI Enable Bit Mask */ +#define CDNS_SPI_ER_DISABLE 0x0 /* SPI Disable Bit Mask */ + +/* SPI FIFO depth in bytes */ +#define CDNS_SPI_FIFO_DEPTH 128 + +/* Default number of chip select lines */ +#define CDNS_SPI_DEFAULT_NUM_CS 4 + +/** + * struct cdns_spi - This definition defines spi driver instance + * @regs: Virtual address of the SPI controller registers + * @ref_clk: Pointer to the peripheral clock + * @pclk: Pointer to the APB clock + * @speed_hz: Current SPI bus clock speed in Hz + * @txbuf: Pointer to the TX buffer + * @rxbuf: Pointer to the RX buffer + * @tx_bytes: Number of bytes left to transfer + * @rx_bytes: Number of bytes requested + * @dev_busy: Device busy flag + * @is_decoded_cs: Flag for decoder property set or not + */ +struct cdns_spi { + void __iomem *regs; + struct clk *ref_clk; + struct clk *pclk; + unsigned int clk_rate; + u32 speed_hz; + const u8 *txbuf; + u8 *rxbuf; + int tx_bytes; + int rx_bytes; + u8 dev_busy; + u32 is_decoded_cs; +}; + +struct cdns_spi_device_data { + bool gpio_requested; +}; + +/* Macros for the SPI controller read/write */ +static inline u32 cdns_spi_read(struct cdns_spi *xspi, u32 offset) +{ + return readl_relaxed(xspi->regs + offset); +} + +static inline void cdns_spi_write(struct cdns_spi *xspi, u32 offset, u32 val) +{ + writel_relaxed(val, xspi->regs + offset); +} + +/** + * cdns_spi_init_hw - Initialize the hardware and configure the SPI controller + * @xspi: Pointer to the cdns_spi structure + * + * On reset the SPI controller is configured to be in master mode, baud rate + * divisor is set to 4, threshold value for TX FIFO not full interrupt is set + * to 1 and size of the word to be transferred as 8 bit. + * This function initializes the SPI controller to disable and clear all the + * interrupts, enable manual slave select and manual start, deselect all the + * chip select lines, and enable the SPI controller. + */ +static void cdns_spi_init_hw(struct cdns_spi *xspi) +{ + u32 ctrl_reg = CDNS_SPI_CR_DEFAULT; + + if (xspi->is_decoded_cs) + ctrl_reg |= CDNS_SPI_CR_PERI_SEL; + + cdns_spi_write(xspi, CDNS_SPI_ER, CDNS_SPI_ER_DISABLE); + cdns_spi_write(xspi, CDNS_SPI_IDR, CDNS_SPI_IXR_ALL); + + /* Clear the RX FIFO */ + while (cdns_spi_read(xspi, CDNS_SPI_ISR) & CDNS_SPI_IXR_RXNEMTY) + cdns_spi_read(xspi, CDNS_SPI_RXD); + + cdns_spi_write(xspi, CDNS_SPI_ISR, CDNS_SPI_IXR_ALL); + cdns_spi_write(xspi, CDNS_SPI_CR, ctrl_reg); + cdns_spi_write(xspi, CDNS_SPI_ER, CDNS_SPI_ER_ENABLE); +} + +/** + * cdns_spi_chipselect - Select or deselect the chip select line + * @spi: Pointer to the spi_device structure + * @is_high: Select(0) or deselect (1) the chip select line + */ +static void cdns_spi_chipselect(struct spi_device *spi, bool is_high) +{ + struct cdns_spi *xspi = spi_master_get_devdata(spi->master); + u32 ctrl_reg; + + ctrl_reg = cdns_spi_read(xspi, CDNS_SPI_CR); + + if (is_high) { + /* Deselect the slave */ + ctrl_reg |= CDNS_SPI_CR_SSCTRL; + } else { + /* Select the slave */ + ctrl_reg &= ~CDNS_SPI_CR_SSCTRL; + if (!(xspi->is_decoded_cs)) + ctrl_reg |= ((~(CDNS_SPI_SS0 << spi->chip_select)) << + CDNS_SPI_SS_SHIFT) & + CDNS_SPI_CR_SSCTRL; + else + ctrl_reg |= (spi->chip_select << CDNS_SPI_SS_SHIFT) & + CDNS_SPI_CR_SSCTRL; + } + + cdns_spi_write(xspi, CDNS_SPI_CR, ctrl_reg); +} + +/** + * cdns_spi_config_clock_mode - Sets clock polarity and phase + * @spi: Pointer to the spi_device structure + * + * Sets the requested clock polarity and phase. + */ +static void cdns_spi_config_clock_mode(struct spi_device *spi) +{ + struct cdns_spi *xspi = spi_master_get_devdata(spi->master); + u32 ctrl_reg, new_ctrl_reg; + + new_ctrl_reg = cdns_spi_read(xspi, CDNS_SPI_CR); + ctrl_reg = new_ctrl_reg; + + /* Set the SPI clock phase and clock polarity */ + new_ctrl_reg &= ~(CDNS_SPI_CR_CPHA | CDNS_SPI_CR_CPOL); + if (spi->mode & SPI_CPHA) + new_ctrl_reg |= CDNS_SPI_CR_CPHA; + if (spi->mode & SPI_CPOL) + new_ctrl_reg |= CDNS_SPI_CR_CPOL; + + if (new_ctrl_reg != ctrl_reg) { + /* + * Just writing the CR register does not seem to apply the clock + * setting changes. This is problematic when changing the clock + * polarity as it will cause the SPI slave to see spurious clock + * transitions. To workaround the issue toggle the ER register. + */ + cdns_spi_write(xspi, CDNS_SPI_ER, CDNS_SPI_ER_DISABLE); + cdns_spi_write(xspi, CDNS_SPI_CR, new_ctrl_reg); + cdns_spi_write(xspi, CDNS_SPI_ER, CDNS_SPI_ER_ENABLE); + } +} + +/** + * cdns_spi_config_clock_freq - Sets clock frequency + * @spi: Pointer to the spi_device structure + * @transfer: Pointer to the spi_transfer structure which provides + * information about next transfer setup parameters + * + * Sets the requested clock frequency. + * Note: If the requested frequency is not an exact match with what can be + * obtained using the prescalar value the driver sets the clock frequency which + * is lower than the requested frequency (maximum lower) for the transfer. If + * the requested frequency is higher or lower than that is supported by the SPI + * controller the driver will set the highest or lowest frequency supported by + * controller. + */ +static void cdns_spi_config_clock_freq(struct spi_device *spi, + struct spi_transfer *transfer) +{ + struct cdns_spi *xspi = spi_master_get_devdata(spi->master); + u32 ctrl_reg, baud_rate_val; + unsigned long frequency; + + frequency = xspi->clk_rate; + + ctrl_reg = cdns_spi_read(xspi, CDNS_SPI_CR); + + /* Set the clock frequency */ + if (xspi->speed_hz != transfer->speed_hz) { + /* first valid value is 1 */ + baud_rate_val = CDNS_SPI_BAUD_DIV_MIN; + while ((baud_rate_val < CDNS_SPI_BAUD_DIV_MAX) && + (frequency / (2 << baud_rate_val)) > transfer->speed_hz) + baud_rate_val++; + + ctrl_reg &= ~CDNS_SPI_CR_BAUD_DIV; + ctrl_reg |= baud_rate_val << CDNS_SPI_BAUD_DIV_SHIFT; + + xspi->speed_hz = frequency / (2 << baud_rate_val); + } + cdns_spi_write(xspi, CDNS_SPI_CR, ctrl_reg); +} + +/** + * cdns_spi_setup_transfer - Configure SPI controller for specified transfer + * @spi: Pointer to the spi_device structure + * @transfer: Pointer to the spi_transfer structure which provides + * information about next transfer setup parameters + * + * Sets the operational mode of SPI controller for the next SPI transfer and + * sets the requested clock frequency. + * + * Return: Always 0 + */ +static int cdns_spi_setup_transfer(struct spi_device *spi, + struct spi_transfer *transfer) +{ + struct cdns_spi *xspi = spi_master_get_devdata(spi->master); + + cdns_spi_config_clock_freq(spi, transfer); + + dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u clock speed\n", + __func__, spi->mode, spi->bits_per_word, + xspi->speed_hz); + + return 0; +} + +/** + * cdns_spi_fill_tx_fifo - Fills the TX FIFO with as many bytes as possible + * @xspi: Pointer to the cdns_spi structure + */ +static void cdns_spi_fill_tx_fifo(struct cdns_spi *xspi) +{ + unsigned long trans_cnt = 0; + + while ((trans_cnt < CDNS_SPI_FIFO_DEPTH) && + (xspi->tx_bytes > 0)) { + + /* When xspi in busy condition, bytes may send failed, + * then spi control did't work thoroughly, add one byte delay + */ + if (cdns_spi_read(xspi, CDNS_SPI_ISR) & + CDNS_SPI_IXR_TXFULL) + udelay(10); + + if (xspi->txbuf) + cdns_spi_write(xspi, CDNS_SPI_TXD, *xspi->txbuf++); + else + cdns_spi_write(xspi, CDNS_SPI_TXD, 0); + + xspi->tx_bytes--; + trans_cnt++; + } +} + +/** + * cdns_spi_irq - Interrupt service routine of the SPI controller + * @irq: IRQ number + * @dev_id: Pointer to the xspi 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 + * fills the TX FIFO if there is any data remaining to be transferred. + * On Mode Fault interrupt this function indicates that transfer is completed, + * the SPI subsystem will identify the error as the remaining bytes to be + * transferred is non-zero. + * + * Return: IRQ_HANDLED when handled; IRQ_NONE otherwise. + */ +static irqreturn_t cdns_spi_irq(int irq, void *dev_id) +{ + struct spi_master *master = dev_id; + struct cdns_spi *xspi = spi_master_get_devdata(master); + u32 intr_status, status; + + status = IRQ_NONE; + intr_status = cdns_spi_read(xspi, CDNS_SPI_ISR); + cdns_spi_write(xspi, CDNS_SPI_ISR, intr_status); + + if (intr_status & CDNS_SPI_IXR_MODF) { + /* Indicate that transfer is completed, the SPI subsystem will + * identify the error as the remaining bytes to be + * transferred is non-zero + */ + cdns_spi_write(xspi, CDNS_SPI_IDR, CDNS_SPI_IXR_DEFAULT); + spi_finalize_current_transfer(master); + status = IRQ_HANDLED; + } else if (intr_status & CDNS_SPI_IXR_TXOW) { + unsigned long trans_cnt; + + trans_cnt = xspi->rx_bytes - xspi->tx_bytes; + + /* Read out the data from the RX FIFO */ + while (trans_cnt) { + u8 data; + + data = cdns_spi_read(xspi, CDNS_SPI_RXD); + if (xspi->rxbuf) + *xspi->rxbuf++ = data; + + xspi->rx_bytes--; + trans_cnt--; + } + + if (xspi->tx_bytes) { + /* There is more data to send */ + cdns_spi_fill_tx_fifo(xspi); + } else { + /* Transfer is completed */ + cdns_spi_write(xspi, CDNS_SPI_IDR, + CDNS_SPI_IXR_DEFAULT); + spi_finalize_current_transfer(master); + } + status = IRQ_HANDLED; + } + + return status; +} + +static int cdns_prepare_message(struct spi_master *master, + struct spi_message *msg) +{ + cdns_spi_config_clock_mode(msg->spi); + return 0; +} + +/** + * cdns_transfer_one - Initiates the SPI transfer + * @master: Pointer to spi_master structure + * @spi: Pointer to the spi_device structure + * @transfer: Pointer to the spi_transfer structure which provides + * information about next transfer parameters + * + * This function fills the TX FIFO, starts the SPI transfer and + * returns a positive transfer count so that core will wait for completion. + * + * Return: Number of bytes transferred in the last transfer + */ +static int cdns_transfer_one(struct spi_master *master, + struct spi_device *spi, + struct spi_transfer *transfer) +{ + struct cdns_spi *xspi = spi_master_get_devdata(master); + + xspi->txbuf = transfer->tx_buf; + xspi->rxbuf = transfer->rx_buf; + xspi->tx_bytes = transfer->len; + xspi->rx_bytes = transfer->len; + + cdns_spi_setup_transfer(spi, transfer); + + cdns_spi_fill_tx_fifo(xspi); + + cdns_spi_write(xspi, CDNS_SPI_IER, CDNS_SPI_IXR_DEFAULT); + return transfer->len; +} + +/** + * cdns_prepare_transfer_hardware - Prepares hardware for transfer. + * @master: Pointer to the spi_master structure which provides + * information about the controller. + * + * This function enables SPI master controller. + * + * Return: 0 always + */ +static int cdns_prepare_transfer_hardware(struct spi_master *master) +{ + struct cdns_spi *xspi = spi_master_get_devdata(master); + + cdns_spi_write(xspi, CDNS_SPI_ER, CDNS_SPI_ER_ENABLE); + + return 0; +} + +/** + * cdns_unprepare_transfer_hardware - Relaxes hardware after transfer + * @master: Pointer to the spi_master structure which provides + * information about the controller. + * + * This function disables the SPI master controller. + * + * Return: 0 always + */ +static int cdns_unprepare_transfer_hardware(struct spi_master *master) +{ + struct cdns_spi *xspi = spi_master_get_devdata(master); + + cdns_spi_write(xspi, CDNS_SPI_ER, CDNS_SPI_ER_DISABLE); + + return 0; +} + +static int cdns_spi_setup(struct spi_device *spi) +{ + + int ret = -EINVAL; + struct cdns_spi_device_data *cdns_spi_data = spi_get_ctldata(spi); + + /* this is a pin managed by the controller, leave it alone */ + if (spi->cs_gpio == -ENOENT) + return 0; + + /* this seems to be the first time we're here */ + if (!cdns_spi_data) { + cdns_spi_data = kzalloc(sizeof(*cdns_spi_data), GFP_KERNEL); + if (!cdns_spi_data) + return -ENOMEM; + cdns_spi_data->gpio_requested = false; + spi_set_ctldata(spi, cdns_spi_data); + } + + /* if we haven't done so, grab the gpio */ + if (!cdns_spi_data->gpio_requested && gpio_is_valid(spi->cs_gpio)) { + ret = gpio_request_one(spi->cs_gpio, + (spi->mode & SPI_CS_HIGH) ? + GPIOF_OUT_INIT_LOW : GPIOF_OUT_INIT_HIGH, + dev_name(&spi->dev)); + if (ret) + dev_err(&spi->dev, "can't request chipselect gpio %d\n", + spi->cs_gpio); + else + cdns_spi_data->gpio_requested = true; + } else { + if (gpio_is_valid(spi->cs_gpio)) { + int mode = ((spi->mode & SPI_CS_HIGH) ? + GPIOF_OUT_INIT_LOW : GPIOF_OUT_INIT_HIGH); + + ret = gpio_direction_output(spi->cs_gpio, mode); + if (ret) + dev_err(&spi->dev, "chipselect gpio %d setup failed (%d)\n", + spi->cs_gpio, ret); + } + } + + return ret; +} + +static void cdns_spi_cleanup(struct spi_device *spi) +{ + struct cdns_spi_device_data *cdns_spi_data = spi_get_ctldata(spi); + + if (cdns_spi_data) { + if (cdns_spi_data->gpio_requested) + gpio_free(spi->cs_gpio); + kfree(cdns_spi_data); + spi_set_ctldata(spi, NULL); + } + +} + +/** + * cdns_spi_probe - Probe method for the SPI driver + * @pdev: Pointer to the platform_device structure + * + * This function initializes the driver data structures and the hardware. + * + * Return: 0 on success and error value on error + */ +static int cdns_spi_probe(struct platform_device *pdev) +{ + int ret = 0, irq; + struct spi_master *master; + struct cdns_spi *xspi; + struct resource *res; + u32 num_cs; + + master = spi_alloc_master(&pdev->dev, sizeof(*xspi)); + if (!master) + return -ENOMEM; + + xspi = spi_master_get_devdata(master); + master->dev.of_node = pdev->dev.of_node; + platform_set_drvdata(pdev, master); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + xspi->regs = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(xspi->regs)) { + ret = PTR_ERR(xspi->regs); + goto remove_master; + } + + xspi->pclk = devm_clk_get(&pdev->dev, "pclk"); + if (IS_ERR(xspi->pclk)) { + dev_err(&pdev->dev, "pclk clock not found.\n"); + ret = PTR_ERR(xspi->pclk); + goto remove_master; + } + + xspi->ref_clk = devm_clk_get(&pdev->dev, "ref_clk"); + if (IS_ERR(xspi->ref_clk)) { + dev_err(&pdev->dev, "ref_clk clock not found.\n"); + ret = PTR_ERR(xspi->ref_clk); + goto remove_master; + } + + ret = clk_prepare_enable(xspi->pclk); + if (ret) { + dev_err(&pdev->dev, "Unable to enable APB clock.\n"); + goto remove_master; + } + + ret = clk_prepare_enable(xspi->ref_clk); + if (ret) { + dev_err(&pdev->dev, "Unable to enable device clock.\n"); + goto clk_dis_apb; + } + + pm_runtime_use_autosuspend(&pdev->dev); + pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT); + pm_runtime_get_noresume(&pdev->dev); + pm_runtime_set_active(&pdev->dev); + pm_runtime_enable(&pdev->dev); + + ret = of_property_read_u32(pdev->dev.of_node, "num-cs", &num_cs); + if (ret < 0) + master->num_chipselect = CDNS_SPI_DEFAULT_NUM_CS; + else + master->num_chipselect = num_cs; + + ret = of_property_read_u32(pdev->dev.of_node, "is-decoded-cs", + &xspi->is_decoded_cs); + if (ret < 0) + xspi->is_decoded_cs = 0; + + /* SPI controller initializations */ + cdns_spi_init_hw(xspi); + + irq = platform_get_irq(pdev, 0); + if (irq <= 0) { + ret = -ENXIO; + dev_err(&pdev->dev, "irq number is invalid\n"); + goto clk_dis_all; + } + + ret = devm_request_irq(&pdev->dev, irq, cdns_spi_irq, + 0, pdev->name, master); + if (ret != 0) { + ret = -ENXIO; + dev_err(&pdev->dev, "request_irq failed\n"); + goto clk_dis_all; + } + + master->prepare_transfer_hardware = cdns_prepare_transfer_hardware; + master->prepare_message = cdns_prepare_message; + master->transfer_one = cdns_transfer_one; + master->unprepare_transfer_hardware = cdns_unprepare_transfer_hardware; + master->set_cs = cdns_spi_chipselect; + master->setup = cdns_spi_setup; + master->cleanup = cdns_spi_cleanup; + master->auto_runtime_pm = true; + master->mode_bits = SPI_CPOL | SPI_CPHA; + + xspi->clk_rate = clk_get_rate(xspi->ref_clk); + /* Set to default valid value */ + master->max_speed_hz = xspi->clk_rate / 4; + xspi->speed_hz = master->max_speed_hz; + + master->bits_per_word_mask = SPI_BPW_MASK(8); + + pm_runtime_mark_last_busy(&pdev->dev); + pm_runtime_put_autosuspend(&pdev->dev); + + ret = spi_register_master(master); + if (ret) { + dev_err(&pdev->dev, "spi_register_master failed\n"); + goto clk_dis_all; + } + + return ret; + +clk_dis_all: + pm_runtime_set_suspended(&pdev->dev); + pm_runtime_disable(&pdev->dev); + clk_disable_unprepare(xspi->ref_clk); +clk_dis_apb: + clk_disable_unprepare(xspi->pclk); +remove_master: + spi_master_put(master); + return ret; +} + +/** + * cdns_spi_remove - Remove method for the SPI driver + * @pdev: Pointer to the platform_device structure + * + * This function is called if a device is physically removed from the system or + * if the driver module is being unloaded. It frees all resources allocated to + * the device. + * + * Return: 0 on success and error value on error + */ +static int cdns_spi_remove(struct platform_device *pdev) +{ + struct spi_master *master = platform_get_drvdata(pdev); + struct cdns_spi *xspi = spi_master_get_devdata(master); + + cdns_spi_write(xspi, CDNS_SPI_ER, CDNS_SPI_ER_DISABLE); + + clk_disable_unprepare(xspi->ref_clk); + clk_disable_unprepare(xspi->pclk); + pm_runtime_set_suspended(&pdev->dev); + pm_runtime_disable(&pdev->dev); + + spi_unregister_master(master); + + return 0; +} + +/** + * cdns_spi_suspend - Suspend method for the SPI driver + * @dev: Address of the platform_device structure + * + * This function disables the SPI controller and + * changes the driver state to "suspend" + * + * Return: 0 on success and error value on error + */ +static int __maybe_unused cdns_spi_suspend(struct device *dev) +{ + struct spi_master *master = dev_get_drvdata(dev); + + return spi_master_suspend(master); +} + +/** + * cdns_spi_resume - Resume method for the SPI driver + * @dev: Address of the platform_device structure + * + * This function changes the driver state to "ready" + * + * Return: 0 on success and error value on error + */ +static int __maybe_unused cdns_spi_resume(struct device *dev) +{ + struct spi_master *master = dev_get_drvdata(dev); + struct cdns_spi *xspi = spi_master_get_devdata(master); + + cdns_spi_init_hw(xspi); + return spi_master_resume(master); +} + +/** + * cdns_spi_runtime_resume - Runtime resume method for the SPI driver + * @dev: Address of the platform_device structure + * + * This function enables the clocks + * + * Return: 0 on success and error value on error + */ +static int __maybe_unused cnds_runtime_resume(struct device *dev) +{ + struct spi_master *master = dev_get_drvdata(dev); + struct cdns_spi *xspi = spi_master_get_devdata(master); + int ret; + + ret = clk_prepare_enable(xspi->pclk); + if (ret) { + dev_err(dev, "Cannot enable APB clock.\n"); + return ret; + } + + ret = clk_prepare_enable(xspi->ref_clk); + if (ret) { + dev_err(dev, "Cannot enable device clock.\n"); + clk_disable_unprepare(xspi->pclk); + return ret; + } + return 0; +} + +/** + * cdns_spi_runtime_suspend - Runtime suspend method for the SPI driver + * @dev: Address of the platform_device structure + * + * This function disables the clocks + * + * Return: Always 0 + */ +static int __maybe_unused cnds_runtime_suspend(struct device *dev) +{ + struct spi_master *master = dev_get_drvdata(dev); + struct cdns_spi *xspi = spi_master_get_devdata(master); + + clk_disable_unprepare(xspi->ref_clk); + clk_disable_unprepare(xspi->pclk); + + return 0; +} + +static const struct dev_pm_ops cdns_spi_dev_pm_ops = { + SET_RUNTIME_PM_OPS(cnds_runtime_suspend, + cnds_runtime_resume, NULL) + SET_SYSTEM_SLEEP_PM_OPS(cdns_spi_suspend, cdns_spi_resume) +}; + +static const struct of_device_id cdns_spi_of_match[] = { + { .compatible = "xlnx,zynq-spi-r1p6" }, + { .compatible = "cdns,spi-r1p6" }, + { /* end of table */ } +}; +MODULE_DEVICE_TABLE(of, cdns_spi_of_match); + +/* cdns_spi_driver - This structure defines the SPI subsystem platform driver */ +static struct platform_driver cdns_spi_driver = { + .probe = cdns_spi_probe, + .remove = cdns_spi_remove, + .driver = { + .name = CDNS_SPI_NAME, + .of_match_table = cdns_spi_of_match, + .pm = &cdns_spi_dev_pm_ops, + }, +}; + +module_platform_driver(cdns_spi_driver); + +MODULE_AUTHOR("Xilinx, Inc."); +MODULE_DESCRIPTION("Cadence SPI driver"); +MODULE_LICENSE("GPL"); |