--- /dev/null
+/*
+ * A driver for the ARM PL022 PrimeCell SSP/SPI bus master.
+ *
+ * Copyright (C) 2008-2012 ST-Ericsson AB
+ * Copyright (C) 2006 STMicroelectronics Pvt. Ltd.
+ *
+ * Author: Linus Walleij <linus.walleij@stericsson.com>
+ *
+ * Initial version inspired by:
+ * linux-2.6.17-rc3-mm1/drivers/spi/pxa2xx_spi.c
+ * Initial adoption to PL022 by:
+ * Sachin Verma <sachin.verma@st.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/ioport.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/spi/spi.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/amba/bus.h>
+#include <linux/amba/pl022.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/scatterlist.h>
+#include <linux/pm_runtime.h>
+#include <linux/gpio.h>
+#include <linux/of_gpio.h>
+#include <linux/pinctrl/consumer.h>
+
+/*
+ * This macro is used to define some register default values.
+ * reg is masked with mask, the OR:ed with an (again masked)
+ * val shifted sb steps to the left.
+ */
+#define SSP_WRITE_BITS(reg, val, mask, sb) \
+ ((reg) = (((reg) & ~(mask)) | (((val)<<(sb)) & (mask))))
+
+/*
+ * This macro is also used to define some default values.
+ * It will just shift val by sb steps to the left and mask
+ * the result with mask.
+ */
+#define GEN_MASK_BITS(val, mask, sb) \
+ (((val)<<(sb)) & (mask))
+
+#define DRIVE_TX 0
+#define DO_NOT_DRIVE_TX 1
+
+#define DO_NOT_QUEUE_DMA 0
+#define QUEUE_DMA 1
+
+#define RX_TRANSFER 1
+#define TX_TRANSFER 2
+
+/*
+ * Macros to access SSP Registers with their offsets
+ */
+#define SSP_CR0(r) (r + 0x000)
+#define SSP_CR1(r) (r + 0x004)
+#define SSP_DR(r) (r + 0x008)
+#define SSP_SR(r) (r + 0x00C)
+#define SSP_CPSR(r) (r + 0x010)
+#define SSP_IMSC(r) (r + 0x014)
+#define SSP_RIS(r) (r + 0x018)
+#define SSP_MIS(r) (r + 0x01C)
+#define SSP_ICR(r) (r + 0x020)
+#define SSP_DMACR(r) (r + 0x024)
+#define SSP_CSR(r) (r + 0x030) /* vendor extension */
+#define SSP_ITCR(r) (r + 0x080)
+#define SSP_ITIP(r) (r + 0x084)
+#define SSP_ITOP(r) (r + 0x088)
+#define SSP_TDR(r) (r + 0x08C)
+
+#define SSP_PID0(r) (r + 0xFE0)
+#define SSP_PID1(r) (r + 0xFE4)
+#define SSP_PID2(r) (r + 0xFE8)
+#define SSP_PID3(r) (r + 0xFEC)
+
+#define SSP_CID0(r) (r + 0xFF0)
+#define SSP_CID1(r) (r + 0xFF4)
+#define SSP_CID2(r) (r + 0xFF8)
+#define SSP_CID3(r) (r + 0xFFC)
+
+/*
+ * SSP Control Register 0 - SSP_CR0
+ */
+#define SSP_CR0_MASK_DSS (0x0FUL << 0)
+#define SSP_CR0_MASK_FRF (0x3UL << 4)
+#define SSP_CR0_MASK_SPO (0x1UL << 6)
+#define SSP_CR0_MASK_SPH (0x1UL << 7)
+#define SSP_CR0_MASK_SCR (0xFFUL << 8)
+
+/*
+ * The ST version of this block moves som bits
+ * in SSP_CR0 and extends it to 32 bits
+ */
+#define SSP_CR0_MASK_DSS_ST (0x1FUL << 0)
+#define SSP_CR0_MASK_HALFDUP_ST (0x1UL << 5)
+#define SSP_CR0_MASK_CSS_ST (0x1FUL << 16)
+#define SSP_CR0_MASK_FRF_ST (0x3UL << 21)
+
+/*
+ * SSP Control Register 0 - SSP_CR1
+ */
+#define SSP_CR1_MASK_LBM (0x1UL << 0)
+#define SSP_CR1_MASK_SSE (0x1UL << 1)
+#define SSP_CR1_MASK_MS (0x1UL << 2)
+#define SSP_CR1_MASK_SOD (0x1UL << 3)
+
+/*
+ * The ST version of this block adds some bits
+ * in SSP_CR1
+ */
+#define SSP_CR1_MASK_RENDN_ST (0x1UL << 4)
+#define SSP_CR1_MASK_TENDN_ST (0x1UL << 5)
+#define SSP_CR1_MASK_MWAIT_ST (0x1UL << 6)
+#define SSP_CR1_MASK_RXIFLSEL_ST (0x7UL << 7)
+#define SSP_CR1_MASK_TXIFLSEL_ST (0x7UL << 10)
+/* This one is only in the PL023 variant */
+#define SSP_CR1_MASK_FBCLKDEL_ST (0x7UL << 13)
+
+/*
+ * SSP Status Register - SSP_SR
+ */
+#define SSP_SR_MASK_TFE (0x1UL << 0) /* Transmit FIFO empty */
+#define SSP_SR_MASK_TNF (0x1UL << 1) /* Transmit FIFO not full */
+#define SSP_SR_MASK_RNE (0x1UL << 2) /* Receive FIFO not empty */
+#define SSP_SR_MASK_RFF (0x1UL << 3) /* Receive FIFO full */
+#define SSP_SR_MASK_BSY (0x1UL << 4) /* Busy Flag */
+
+/*
+ * SSP Clock Prescale Register - SSP_CPSR
+ */
+#define SSP_CPSR_MASK_CPSDVSR (0xFFUL << 0)
+
+/*
+ * SSP Interrupt Mask Set/Clear Register - SSP_IMSC
+ */
+#define SSP_IMSC_MASK_RORIM (0x1UL << 0) /* Receive Overrun Interrupt mask */
+#define SSP_IMSC_MASK_RTIM (0x1UL << 1) /* Receive timeout Interrupt mask */
+#define SSP_IMSC_MASK_RXIM (0x1UL << 2) /* Receive FIFO Interrupt mask */
+#define SSP_IMSC_MASK_TXIM (0x1UL << 3) /* Transmit FIFO Interrupt mask */
+
+/*
+ * SSP Raw Interrupt Status Register - SSP_RIS
+ */
+/* Receive Overrun Raw Interrupt status */
+#define SSP_RIS_MASK_RORRIS (0x1UL << 0)
+/* Receive Timeout Raw Interrupt status */
+#define SSP_RIS_MASK_RTRIS (0x1UL << 1)
+/* Receive FIFO Raw Interrupt status */
+#define SSP_RIS_MASK_RXRIS (0x1UL << 2)
+/* Transmit FIFO Raw Interrupt status */
+#define SSP_RIS_MASK_TXRIS (0x1UL << 3)
+
+/*
+ * SSP Masked Interrupt Status Register - SSP_MIS
+ */
+/* Receive Overrun Masked Interrupt status */
+#define SSP_MIS_MASK_RORMIS (0x1UL << 0)
+/* Receive Timeout Masked Interrupt status */
+#define SSP_MIS_MASK_RTMIS (0x1UL << 1)
+/* Receive FIFO Masked Interrupt status */
+#define SSP_MIS_MASK_RXMIS (0x1UL << 2)
+/* Transmit FIFO Masked Interrupt status */
+#define SSP_MIS_MASK_TXMIS (0x1UL << 3)
+
+/*
+ * SSP Interrupt Clear Register - SSP_ICR
+ */
+/* Receive Overrun Raw Clear Interrupt bit */
+#define SSP_ICR_MASK_RORIC (0x1UL << 0)
+/* Receive Timeout Clear Interrupt bit */
+#define SSP_ICR_MASK_RTIC (0x1UL << 1)
+
+/*
+ * SSP DMA Control Register - SSP_DMACR
+ */
+/* Receive DMA Enable bit */
+#define SSP_DMACR_MASK_RXDMAE (0x1UL << 0)
+/* Transmit DMA Enable bit */
+#define SSP_DMACR_MASK_TXDMAE (0x1UL << 1)
+
+/*
+ * SSP Chip Select Control Register - SSP_CSR
+ * (vendor extension)
+ */
+#define SSP_CSR_CSVALUE_MASK (0x1FUL << 0)
+
+/*
+ * SSP Integration Test control Register - SSP_ITCR
+ */
+#define SSP_ITCR_MASK_ITEN (0x1UL << 0)
+#define SSP_ITCR_MASK_TESTFIFO (0x1UL << 1)
+
+/*
+ * SSP Integration Test Input Register - SSP_ITIP
+ */
+#define ITIP_MASK_SSPRXD (0x1UL << 0)
+#define ITIP_MASK_SSPFSSIN (0x1UL << 1)
+#define ITIP_MASK_SSPCLKIN (0x1UL << 2)
+#define ITIP_MASK_RXDMAC (0x1UL << 3)
+#define ITIP_MASK_TXDMAC (0x1UL << 4)
+#define ITIP_MASK_SSPTXDIN (0x1UL << 5)
+
+/*
+ * SSP Integration Test output Register - SSP_ITOP
+ */
+#define ITOP_MASK_SSPTXD (0x1UL << 0)
+#define ITOP_MASK_SSPFSSOUT (0x1UL << 1)
+#define ITOP_MASK_SSPCLKOUT (0x1UL << 2)
+#define ITOP_MASK_SSPOEn (0x1UL << 3)
+#define ITOP_MASK_SSPCTLOEn (0x1UL << 4)
+#define ITOP_MASK_RORINTR (0x1UL << 5)
+#define ITOP_MASK_RTINTR (0x1UL << 6)
+#define ITOP_MASK_RXINTR (0x1UL << 7)
+#define ITOP_MASK_TXINTR (0x1UL << 8)
+#define ITOP_MASK_INTR (0x1UL << 9)
+#define ITOP_MASK_RXDMABREQ (0x1UL << 10)
+#define ITOP_MASK_RXDMASREQ (0x1UL << 11)
+#define ITOP_MASK_TXDMABREQ (0x1UL << 12)
+#define ITOP_MASK_TXDMASREQ (0x1UL << 13)
+
+/*
+ * SSP Test Data Register - SSP_TDR
+ */
+#define TDR_MASK_TESTDATA (0xFFFFFFFF)
+
+/*
+ * Message State
+ * we use the spi_message.state (void *) pointer to
+ * hold a single state value, that's why all this
+ * (void *) casting is done here.
+ */
+#define STATE_START ((void *) 0)
+#define STATE_RUNNING ((void *) 1)
+#define STATE_DONE ((void *) 2)
+#define STATE_ERROR ((void *) -1)
+
+/*
+ * SSP State - Whether Enabled or Disabled
+ */
+#define SSP_DISABLED (0)
+#define SSP_ENABLED (1)
+
+/*
+ * SSP DMA State - Whether DMA Enabled or Disabled
+ */
+#define SSP_DMA_DISABLED (0)
+#define SSP_DMA_ENABLED (1)
+
+/*
+ * SSP Clock Defaults
+ */
+#define SSP_DEFAULT_CLKRATE 0x2
+#define SSP_DEFAULT_PRESCALE 0x40
+
+/*
+ * SSP Clock Parameter ranges
+ */
+#define CPSDVR_MIN 0x02
+#define CPSDVR_MAX 0xFE
+#define SCR_MIN 0x00
+#define SCR_MAX 0xFF
+
+/*
+ * SSP Interrupt related Macros
+ */
+#define DEFAULT_SSP_REG_IMSC 0x0UL
+#define DISABLE_ALL_INTERRUPTS DEFAULT_SSP_REG_IMSC
+#define ENABLE_ALL_INTERRUPTS ( \
+ SSP_IMSC_MASK_RORIM | \
+ SSP_IMSC_MASK_RTIM | \
+ SSP_IMSC_MASK_RXIM | \
+ SSP_IMSC_MASK_TXIM \
+)
+
+#define CLEAR_ALL_INTERRUPTS 0x3
+
+#define SPI_POLLING_TIMEOUT 1000
+
+/*
+ * The type of reading going on on this chip
+ */
+enum ssp_reading {
+ READING_NULL,
+ READING_U8,
+ READING_U16,
+ READING_U32
+};
+
+/**
+ * The type of writing going on on this chip
+ */
+enum ssp_writing {
+ WRITING_NULL,
+ WRITING_U8,
+ WRITING_U16,
+ WRITING_U32
+};
+
+/**
+ * struct vendor_data - vendor-specific config parameters
+ * for PL022 derivates
+ * @fifodepth: depth of FIFOs (both)
+ * @max_bpw: maximum number of bits per word
+ * @unidir: supports unidirection transfers
+ * @extended_cr: 32 bit wide control register 0 with extra
+ * features and extra features in CR1 as found in the ST variants
+ * @pl023: supports a subset of the ST extensions called "PL023"
+ * @internal_cs_ctrl: supports chip select control register
+ */
+struct vendor_data {
+ int fifodepth;
+ int max_bpw;
+ bool unidir;
+ bool extended_cr;
+ bool pl023;
+ bool loopback;
+ bool internal_cs_ctrl;
+};
+
+/**
+ * struct pl022 - This is the private SSP driver data structure
+ * @adev: AMBA device model hookup
+ * @vendor: vendor data for the IP block
+ * @phybase: the physical memory where the SSP device resides
+ * @virtbase: the virtual memory where the SSP is mapped
+ * @clk: outgoing clock "SPICLK" for the SPI bus
+ * @master: SPI framework hookup
+ * @master_info: controller-specific data from machine setup
+ * @kworker: thread struct for message pump
+ * @kworker_task: pointer to task for message pump kworker thread
+ * @pump_messages: work struct for scheduling work to the message pump
+ * @queue_lock: spinlock to syncronise access to message queue
+ * @queue: message queue
+ * @busy: message pump is busy
+ * @running: message pump is running
+ * @pump_transfers: Tasklet used in Interrupt Transfer mode
+ * @cur_msg: Pointer to current spi_message being processed
+ * @cur_transfer: Pointer to current spi_transfer
+ * @cur_chip: pointer to current clients chip(assigned from controller_state)
+ * @next_msg_cs_active: the next message in the queue has been examined
+ * and it was found that it uses the same chip select as the previous
+ * message, so we left it active after the previous transfer, and it's
+ * active already.
+ * @tx: current position in TX buffer to be read
+ * @tx_end: end position in TX buffer to be read
+ * @rx: current position in RX buffer to be written
+ * @rx_end: end position in RX buffer to be written
+ * @read: the type of read currently going on
+ * @write: the type of write currently going on
+ * @exp_fifo_level: expected FIFO level
+ * @dma_rx_channel: optional channel for RX DMA
+ * @dma_tx_channel: optional channel for TX DMA
+ * @sgt_rx: scattertable for the RX transfer
+ * @sgt_tx: scattertable for the TX transfer
+ * @dummypage: a dummy page used for driving data on the bus with DMA
+ * @cur_cs: current chip select (gpio)
+ * @chipselects: list of chipselects (gpios)
+ */
+struct pl022 {
+ struct amba_device *adev;
+ struct vendor_data *vendor;
+ resource_size_t phybase;
+ void __iomem *virtbase;
+ struct clk *clk;
+ struct spi_master *master;
+ struct pl022_ssp_controller *master_info;
+ /* Message per-transfer pump */
+ struct tasklet_struct pump_transfers;
+ struct spi_message *cur_msg;
+ struct spi_transfer *cur_transfer;
+ struct chip_data *cur_chip;
+ bool next_msg_cs_active;
+ void *tx;
+ void *tx_end;
+ void *rx;
+ void *rx_end;
+ enum ssp_reading read;
+ enum ssp_writing write;
+ u32 exp_fifo_level;
+ enum ssp_rx_level_trig rx_lev_trig;
+ enum ssp_tx_level_trig tx_lev_trig;
+ /* DMA settings */
+#ifdef CONFIG_DMA_ENGINE
+ struct dma_chan *dma_rx_channel;
+ struct dma_chan *dma_tx_channel;
+ struct sg_table sgt_rx;
+ struct sg_table sgt_tx;
+ char *dummypage;
+ bool dma_running;
+#endif
+ int cur_cs;
+ int *chipselects;
+};
+
+/**
+ * struct chip_data - To maintain runtime state of SSP for each client chip
+ * @cr0: Value of control register CR0 of SSP - on later ST variants this
+ * register is 32 bits wide rather than just 16
+ * @cr1: Value of control register CR1 of SSP
+ * @dmacr: Value of DMA control Register of SSP
+ * @cpsr: Value of Clock prescale register
+ * @n_bytes: how many bytes(power of 2) reqd for a given data width of client
+ * @enable_dma: Whether to enable DMA or not
+ * @read: function ptr to be used to read when doing xfer for this chip
+ * @write: function ptr to be used to write when doing xfer for this chip
+ * @cs_control: chip select callback provided by chip
+ * @xfer_type: polling/interrupt/DMA
+ *
+ * Runtime state of the SSP controller, maintained per chip,
+ * This would be set according to the current message that would be served
+ */
+struct chip_data {
+ u32 cr0;
+ u16 cr1;
+ u16 dmacr;
+ u16 cpsr;
+ u8 n_bytes;
+ bool enable_dma;
+ enum ssp_reading read;
+ enum ssp_writing write;
+ void (*cs_control) (u32 command);
+ int xfer_type;
+};
+
+/**
+ * null_cs_control - Dummy chip select function
+ * @command: select/delect the chip
+ *
+ * If no chip select function is provided by client this is used as dummy
+ * chip select
+ */
+static void null_cs_control(u32 command)
+{
+ pr_debug("pl022: dummy chip select control, CS=0x%x\n", command);
+}
+
+/**
+ * internal_cs_control - Control chip select signals via SSP_CSR.
+ * @pl022: SSP driver private data structure
+ * @command: select/delect the chip
+ *
+ * Used on controller with internal chip select control via SSP_CSR register
+ * (vendor extension). Each of the 5 LSB in the register controls one chip
+ * select signal.
+ */
+static void internal_cs_control(struct pl022 *pl022, u32 command)
+{
+ u32 tmp;
+
+ tmp = readw(SSP_CSR(pl022->virtbase));
+ if (command == SSP_CHIP_SELECT)
+ tmp &= ~BIT(pl022->cur_cs);
+ else
+ tmp |= BIT(pl022->cur_cs);
+ writew(tmp, SSP_CSR(pl022->virtbase));
+}
+
+static void pl022_cs_control(struct pl022 *pl022, u32 command)
+{
+ if (pl022->vendor->internal_cs_ctrl)
+ internal_cs_control(pl022, command);
+ else if (gpio_is_valid(pl022->cur_cs))
+ gpio_set_value(pl022->cur_cs, command);
+ else
+ pl022->cur_chip->cs_control(command);
+}
+
+/**
+ * giveback - current spi_message is over, schedule next message and call
+ * callback of this message. Assumes that caller already
+ * set message->status; dma and pio irqs are blocked
+ * @pl022: SSP driver private data structure
+ */
+static void giveback(struct pl022 *pl022)
+{
+ struct spi_transfer *last_transfer;
+ pl022->next_msg_cs_active = false;
+
+ last_transfer = list_last_entry(&pl022->cur_msg->transfers,
+ struct spi_transfer, transfer_list);
+
+ /* Delay if requested before any change in chip select */
+ if (last_transfer->delay_usecs)
+ /*
+ * FIXME: This runs in interrupt context.
+ * Is this really smart?
+ */
+ udelay(last_transfer->delay_usecs);
+
+ if (!last_transfer->cs_change) {
+ struct spi_message *next_msg;
+
+ /*
+ * cs_change was not set. We can keep the chip select
+ * enabled if there is message in the queue and it is
+ * for the same spi device.
+ *
+ * We cannot postpone this until pump_messages, because
+ * after calling msg->complete (below) the driver that
+ * sent the current message could be unloaded, which
+ * could invalidate the cs_control() callback...
+ */
+ /* get a pointer to the next message, if any */
+ next_msg = spi_get_next_queued_message(pl022->master);
+
+ /*
+ * see if the next and current messages point
+ * to the same spi device.
+ */
+ if (next_msg && next_msg->spi != pl022->cur_msg->spi)
+ next_msg = NULL;
+ if (!next_msg || pl022->cur_msg->state == STATE_ERROR)
+ pl022_cs_control(pl022, SSP_CHIP_DESELECT);
+ else
+ pl022->next_msg_cs_active = true;
+
+ }
+
+ pl022->cur_msg = NULL;
+ pl022->cur_transfer = NULL;
+ pl022->cur_chip = NULL;
+
+ /* disable the SPI/SSP operation */
+ writew((readw(SSP_CR1(pl022->virtbase)) &
+ (~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
+
+ spi_finalize_current_message(pl022->master);
+}
+
+/**
+ * flush - flush the FIFO to reach a clean state
+ * @pl022: SSP driver private data structure
+ */
+static int flush(struct pl022 *pl022)
+{
+ unsigned long limit = loops_per_jiffy << 1;
+
+ dev_dbg(&pl022->adev->dev, "flush\n");
+ do {
+ while (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
+ readw(SSP_DR(pl022->virtbase));
+ } while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_BSY) && limit--);
+
+ pl022->exp_fifo_level = 0;
+
+ return limit;
+}
+
+/**
+ * restore_state - Load configuration of current chip
+ * @pl022: SSP driver private data structure
+ */
+static void restore_state(struct pl022 *pl022)
+{
+ struct chip_data *chip = pl022->cur_chip;
+
+ if (pl022->vendor->extended_cr)
+ writel(chip->cr0, SSP_CR0(pl022->virtbase));
+ else
+ writew(chip->cr0, SSP_CR0(pl022->virtbase));
+ writew(chip->cr1, SSP_CR1(pl022->virtbase));
+ writew(chip->dmacr, SSP_DMACR(pl022->virtbase));
+ writew(chip->cpsr, SSP_CPSR(pl022->virtbase));
+ writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
+ writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
+}
+
+/*
+ * Default SSP Register Values
+ */
+#define DEFAULT_SSP_REG_CR0 ( \
+ GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS, 0) | \
+ GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF, 4) | \
+ GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
+ GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
+ GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \
+)
+
+/* ST versions have slightly different bit layout */
+#define DEFAULT_SSP_REG_CR0_ST ( \
+ GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0) | \
+ GEN_MASK_BITS(SSP_MICROWIRE_CHANNEL_FULL_DUPLEX, SSP_CR0_MASK_HALFDUP_ST, 5) | \
+ GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
+ GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
+ GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) | \
+ GEN_MASK_BITS(SSP_BITS_8, SSP_CR0_MASK_CSS_ST, 16) | \
+ GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF_ST, 21) \
+)
+
+/* The PL023 version is slightly different again */
+#define DEFAULT_SSP_REG_CR0_ST_PL023 ( \
+ GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0) | \
+ GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
+ GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
+ GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \
+)
+
+#define DEFAULT_SSP_REG_CR1 ( \
+ GEN_MASK_BITS(LOOPBACK_DISABLED, SSP_CR1_MASK_LBM, 0) | \
+ GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
+ GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
+ GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) \
+)
+
+/* ST versions extend this register to use all 16 bits */
+#define DEFAULT_SSP_REG_CR1_ST ( \
+ DEFAULT_SSP_REG_CR1 | \
+ GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
+ GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
+ GEN_MASK_BITS(SSP_MWIRE_WAIT_ZERO, SSP_CR1_MASK_MWAIT_ST, 6) |\
+ GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
+ GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) \
+)
+
+/*
+ * The PL023 variant has further differences: no loopback mode, no microwire
+ * support, and a new clock feedback delay setting.
+ */
+#define DEFAULT_SSP_REG_CR1_ST_PL023 ( \
+ GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
+ GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
+ GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) | \
+ GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
+ GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
+ GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
+ GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) | \
+ GEN_MASK_BITS(SSP_FEEDBACK_CLK_DELAY_NONE, SSP_CR1_MASK_FBCLKDEL_ST, 13) \
+)
+
+#define DEFAULT_SSP_REG_CPSR ( \
+ GEN_MASK_BITS(SSP_DEFAULT_PRESCALE, SSP_CPSR_MASK_CPSDVSR, 0) \
+)
+
+#define DEFAULT_SSP_REG_DMACR (\
+ GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_RXDMAE, 0) | \
+ GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_TXDMAE, 1) \
+)
+
+/**
+ * load_ssp_default_config - Load default configuration for SSP
+ * @pl022: SSP driver private data structure
+ */
+static void load_ssp_default_config(struct pl022 *pl022)
+{
+ if (pl022->vendor->pl023) {
+ writel(DEFAULT_SSP_REG_CR0_ST_PL023, SSP_CR0(pl022->virtbase));
+ writew(DEFAULT_SSP_REG_CR1_ST_PL023, SSP_CR1(pl022->virtbase));
+ } else if (pl022->vendor->extended_cr) {
+ writel(DEFAULT_SSP_REG_CR0_ST, SSP_CR0(pl022->virtbase));
+ writew(DEFAULT_SSP_REG_CR1_ST, SSP_CR1(pl022->virtbase));
+ } else {
+ writew(DEFAULT_SSP_REG_CR0, SSP_CR0(pl022->virtbase));
+ writew(DEFAULT_SSP_REG_CR1, SSP_CR1(pl022->virtbase));
+ }
+ writew(DEFAULT_SSP_REG_DMACR, SSP_DMACR(pl022->virtbase));
+ writew(DEFAULT_SSP_REG_CPSR, SSP_CPSR(pl022->virtbase));
+ writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
+ writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
+}
+
+/**
+ * This will write to TX and read from RX according to the parameters
+ * set in pl022.
+ */
+static void readwriter(struct pl022 *pl022)
+{
+
+ /*
+ * The FIFO depth is different between primecell variants.
+ * I believe filling in too much in the FIFO might cause
+ * errons in 8bit wide transfers on ARM variants (just 8 words
+ * FIFO, means only 8x8 = 64 bits in FIFO) at least.
+ *
+ * To prevent this issue, the TX FIFO is only filled to the
+ * unused RX FIFO fill length, regardless of what the TX
+ * FIFO status flag indicates.
+ */
+ dev_dbg(&pl022->adev->dev,
+ "%s, rx: %p, rxend: %p, tx: %p, txend: %p\n",
+ __func__, pl022->rx, pl022->rx_end, pl022->tx, pl022->tx_end);
+
+ /* Read as much as you can */
+ while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
+ && (pl022->rx < pl022->rx_end)) {
+ switch (pl022->read) {
+ case READING_NULL:
+ readw(SSP_DR(pl022->virtbase));
+ break;
+ case READING_U8:
+ *(u8 *) (pl022->rx) =
+ readw(SSP_DR(pl022->virtbase)) & 0xFFU;
+ break;
+ case READING_U16:
+ *(u16 *) (pl022->rx) =
+ (u16) readw(SSP_DR(pl022->virtbase));
+ break;
+ case READING_U32:
+ *(u32 *) (pl022->rx) =
+ readl(SSP_DR(pl022->virtbase));
+ break;
+ }
+ pl022->rx += (pl022->cur_chip->n_bytes);
+ pl022->exp_fifo_level--;
+ }
+ /*
+ * Write as much as possible up to the RX FIFO size
+ */
+ while ((pl022->exp_fifo_level < pl022->vendor->fifodepth)
+ && (pl022->tx < pl022->tx_end)) {
+ switch (pl022->write) {
+ case WRITING_NULL:
+ writew(0x0, SSP_DR(pl022->virtbase));
+ break;
+ case WRITING_U8:
+ writew(*(u8 *) (pl022->tx), SSP_DR(pl022->virtbase));
+ break;
+ case WRITING_U16:
+ writew((*(u16 *) (pl022->tx)), SSP_DR(pl022->virtbase));
+ break;
+ case WRITING_U32:
+ writel(*(u32 *) (pl022->tx), SSP_DR(pl022->virtbase));
+ break;
+ }
+ pl022->tx += (pl022->cur_chip->n_bytes);
+ pl022->exp_fifo_level++;
+ /*
+ * This inner reader takes care of things appearing in the RX
+ * FIFO as we're transmitting. This will happen a lot since the
+ * clock starts running when you put things into the TX FIFO,
+ * and then things are continuously clocked into the RX FIFO.
+ */
+ while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
+ && (pl022->rx < pl022->rx_end)) {
+ switch (pl022->read) {
+ case READING_NULL:
+ readw(SSP_DR(pl022->virtbase));
+ break;
+ case READING_U8:
+ *(u8 *) (pl022->rx) =
+ readw(SSP_DR(pl022->virtbase)) & 0xFFU;
+ break;
+ case READING_U16:
+ *(u16 *) (pl022->rx) =
+ (u16) readw(SSP_DR(pl022->virtbase));
+ break;
+ case READING_U32:
+ *(u32 *) (pl022->rx) =
+ readl(SSP_DR(pl022->virtbase));
+ break;
+ }
+ pl022->rx += (pl022->cur_chip->n_bytes);
+ pl022->exp_fifo_level--;
+ }
+ }
+ /*
+ * When we exit here the TX FIFO should be full and the RX FIFO
+ * should be empty
+ */
+}
+
+/**
+ * next_transfer - Move to the Next transfer in the current spi message
+ * @pl022: SSP driver private data structure
+ *
+ * This function moves though the linked list of spi transfers in the
+ * current spi message and returns with the state of current spi
+ * message i.e whether its last transfer is done(STATE_DONE) or
+ * Next transfer is ready(STATE_RUNNING)
+ */
+static void *next_transfer(struct pl022 *pl022)
+{
+ struct spi_message *msg = pl022->cur_msg;
+ struct spi_transfer *trans = pl022->cur_transfer;
+
+ /* Move to next transfer */
+ if (trans->transfer_list.next != &msg->transfers) {
+ pl022->cur_transfer =
+ list_entry(trans->transfer_list.next,
+ struct spi_transfer, transfer_list);
+ return STATE_RUNNING;
+ }
+ return STATE_DONE;
+}
+
+/*
+ * This DMA functionality is only compiled in if we have
+ * access to the generic DMA devices/DMA engine.
+ */
+#ifdef CONFIG_DMA_ENGINE
+static void unmap_free_dma_scatter(struct pl022 *pl022)
+{
+ /* Unmap and free the SG tables */
+ dma_unmap_sg(pl022->dma_tx_channel->device->dev, pl022->sgt_tx.sgl,
+ pl022->sgt_tx.nents, DMA_TO_DEVICE);
+ dma_unmap_sg(pl022->dma_rx_channel->device->dev, pl022->sgt_rx.sgl,
+ pl022->sgt_rx.nents, DMA_FROM_DEVICE);
+ sg_free_table(&pl022->sgt_rx);
+ sg_free_table(&pl022->sgt_tx);
+}
+
+static void dma_callback(void *data)
+{
+ struct pl022 *pl022 = data;
+ struct spi_message *msg = pl022->cur_msg;
+
+ BUG_ON(!pl022->sgt_rx.sgl);
+
+#ifdef VERBOSE_DEBUG
+ /*
+ * Optionally dump out buffers to inspect contents, this is
+ * good if you want to convince yourself that the loopback
+ * read/write contents are the same, when adopting to a new
+ * DMA engine.
+ */
+ {
+ struct scatterlist *sg;
+ unsigned int i;
+
+ dma_sync_sg_for_cpu(&pl022->adev->dev,
+ pl022->sgt_rx.sgl,
+ pl022->sgt_rx.nents,
+ DMA_FROM_DEVICE);
+
+ for_each_sg(pl022->sgt_rx.sgl, sg, pl022->sgt_rx.nents, i) {
+ dev_dbg(&pl022->adev->dev, "SPI RX SG ENTRY: %d", i);
+ print_hex_dump(KERN_ERR, "SPI RX: ",
+ DUMP_PREFIX_OFFSET,
+ 16,
+ 1,
+ sg_virt(sg),
+ sg_dma_len(sg),
+ 1);
+ }
+ for_each_sg(pl022->sgt_tx.sgl, sg, pl022->sgt_tx.nents, i) {
+ dev_dbg(&pl022->adev->dev, "SPI TX SG ENTRY: %d", i);
+ print_hex_dump(KERN_ERR, "SPI TX: ",
+ DUMP_PREFIX_OFFSET,
+ 16,
+ 1,
+ sg_virt(sg),
+ sg_dma_len(sg),
+ 1);
+ }
+ }
+#endif
+
+ unmap_free_dma_scatter(pl022);
+
+ /* Update total bytes transferred */
+ msg->actual_length += pl022->cur_transfer->len;
+ if (pl022->cur_transfer->cs_change)
+ pl022_cs_control(pl022, SSP_CHIP_DESELECT);
+
+ /* Move to next transfer */
+ msg->state = next_transfer(pl022);
+ tasklet_schedule(&pl022->pump_transfers);
+}
+
+static void setup_dma_scatter(struct pl022 *pl022,
+ void *buffer,
+ unsigned int length,
+ struct sg_table *sgtab)
+{
+ struct scatterlist *sg;
+ int bytesleft = length;
+ void *bufp = buffer;
+ int mapbytes;
+ int i;
+
+ if (buffer) {
+ for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
+ /*
+ * If there are less bytes left than what fits
+ * in the current page (plus page alignment offset)
+ * we just feed in this, else we stuff in as much
+ * as we can.
+ */
+ if (bytesleft < (PAGE_SIZE - offset_in_page(bufp)))
+ mapbytes = bytesleft;
+ else
+ mapbytes = PAGE_SIZE - offset_in_page(bufp);
+ sg_set_page(sg, virt_to_page(bufp),
+ mapbytes, offset_in_page(bufp));
+ bufp += mapbytes;
+ bytesleft -= mapbytes;
+ dev_dbg(&pl022->adev->dev,
+ "set RX/TX target page @ %p, %d bytes, %d left\n",
+ bufp, mapbytes, bytesleft);
+ }
+ } else {
+ /* Map the dummy buffer on every page */
+ for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
+ if (bytesleft < PAGE_SIZE)
+ mapbytes = bytesleft;
+ else
+ mapbytes = PAGE_SIZE;
+ sg_set_page(sg, virt_to_page(pl022->dummypage),
+ mapbytes, 0);
+ bytesleft -= mapbytes;
+ dev_dbg(&pl022->adev->dev,
+ "set RX/TX to dummy page %d bytes, %d left\n",
+ mapbytes, bytesleft);
+
+ }
+ }
+ BUG_ON(bytesleft);
+}
+
+/**
+ * configure_dma - configures the channels for the next transfer
+ * @pl022: SSP driver's private data structure
+ */
+static int configure_dma(struct pl022 *pl022)
+{
+ struct dma_slave_config rx_conf = {
+ .src_addr = SSP_DR(pl022->phybase),
+ .direction = DMA_DEV_TO_MEM,
+ .device_fc = false,
+ };
+ struct dma_slave_config tx_conf = {
+ .dst_addr = SSP_DR(pl022->phybase),
+ .direction = DMA_MEM_TO_DEV,
+ .device_fc = false,
+ };
+ unsigned int pages;
+ int ret;
+ int rx_sglen, tx_sglen;
+ struct dma_chan *rxchan = pl022->dma_rx_channel;
+ struct dma_chan *txchan = pl022->dma_tx_channel;
+ struct dma_async_tx_descriptor *rxdesc;
+ struct dma_async_tx_descriptor *txdesc;
+
+ /* Check that the channels are available */
+ if (!rxchan || !txchan)
+ return -ENODEV;
+
+ /*
+ * If supplied, the DMA burstsize should equal the FIFO trigger level.
+ * Notice that the DMA engine uses one-to-one mapping. Since we can
+ * not trigger on 2 elements this needs explicit mapping rather than
+ * calculation.
+ */
+ switch (pl022->rx_lev_trig) {
+ case SSP_RX_1_OR_MORE_ELEM:
+ rx_conf.src_maxburst = 1;
+ break;
+ case SSP_RX_4_OR_MORE_ELEM:
+ rx_conf.src_maxburst = 4;
+ break;
+ case SSP_RX_8_OR_MORE_ELEM:
+ rx_conf.src_maxburst = 8;
+ break;
+ case SSP_RX_16_OR_MORE_ELEM:
+ rx_conf.src_maxburst = 16;
+ break;
+ case SSP_RX_32_OR_MORE_ELEM:
+ rx_conf.src_maxburst = 32;
+ break;
+ default:
+ rx_conf.src_maxburst = pl022->vendor->fifodepth >> 1;
+ break;
+ }
+
+ switch (pl022->tx_lev_trig) {
+ case SSP_TX_1_OR_MORE_EMPTY_LOC:
+ tx_conf.dst_maxburst = 1;
+ break;
+ case SSP_TX_4_OR_MORE_EMPTY_LOC:
+ tx_conf.dst_maxburst = 4;
+ break;
+ case SSP_TX_8_OR_MORE_EMPTY_LOC:
+ tx_conf.dst_maxburst = 8;
+ break;
+ case SSP_TX_16_OR_MORE_EMPTY_LOC:
+ tx_conf.dst_maxburst = 16;
+ break;
+ case SSP_TX_32_OR_MORE_EMPTY_LOC:
+ tx_conf.dst_maxburst = 32;
+ break;
+ default:
+ tx_conf.dst_maxburst = pl022->vendor->fifodepth >> 1;
+ break;
+ }
+
+ switch (pl022->read) {
+ case READING_NULL:
+ /* Use the same as for writing */
+ rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
+ break;
+ case READING_U8:
+ rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ break;
+ case READING_U16:
+ rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
+ break;
+ case READING_U32:
+ rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+ break;
+ }
+
+ switch (pl022->write) {
+ case WRITING_NULL:
+ /* Use the same as for reading */
+ tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
+ break;
+ case WRITING_U8:
+ tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ break;
+ case WRITING_U16:
+ tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
+ break;
+ case WRITING_U32:
+ tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+ break;
+ }
+
+ /* SPI pecularity: we need to read and write the same width */
+ if (rx_conf.src_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
+ rx_conf.src_addr_width = tx_conf.dst_addr_width;
+ if (tx_conf.dst_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
+ tx_conf.dst_addr_width = rx_conf.src_addr_width;
+ BUG_ON(rx_conf.src_addr_width != tx_conf.dst_addr_width);
+
+ dmaengine_slave_config(rxchan, &rx_conf);
+ dmaengine_slave_config(txchan, &tx_conf);
+
+ /* Create sglists for the transfers */
+ pages = DIV_ROUND_UP(pl022->cur_transfer->len, PAGE_SIZE);
+ dev_dbg(&pl022->adev->dev, "using %d pages for transfer\n", pages);
+
+ ret = sg_alloc_table(&pl022->sgt_rx, pages, GFP_ATOMIC);
+ if (ret)
+ goto err_alloc_rx_sg;
+
+ ret = sg_alloc_table(&pl022->sgt_tx, pages, GFP_ATOMIC);
+ if (ret)
+ goto err_alloc_tx_sg;
+
+ /* Fill in the scatterlists for the RX+TX buffers */
+ setup_dma_scatter(pl022, pl022->rx,
+ pl022->cur_transfer->len, &pl022->sgt_rx);
+ setup_dma_scatter(pl022, pl022->tx,
+ pl022->cur_transfer->len, &pl022->sgt_tx);
+
+ /* Map DMA buffers */
+ rx_sglen = dma_map_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
+ pl022->sgt_rx.nents, DMA_FROM_DEVICE);
+ if (!rx_sglen)
+ goto err_rx_sgmap;
+
+ tx_sglen = dma_map_sg(txchan->device->dev, pl022->sgt_tx.sgl,
+ pl022->sgt_tx.nents, DMA_TO_DEVICE);
+ if (!tx_sglen)
+ goto err_tx_sgmap;
+
+ /* Send both scatterlists */
+ rxdesc = dmaengine_prep_slave_sg(rxchan,
+ pl022->sgt_rx.sgl,
+ rx_sglen,
+ DMA_DEV_TO_MEM,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!rxdesc)
+ goto err_rxdesc;
+
+ txdesc = dmaengine_prep_slave_sg(txchan,
+ pl022->sgt_tx.sgl,
+ tx_sglen,
+ DMA_MEM_TO_DEV,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!txdesc)
+ goto err_txdesc;
+
+ /* Put the callback on the RX transfer only, that should finish last */
+ rxdesc->callback = dma_callback;
+ rxdesc->callback_param = pl022;
+
+ /* Submit and fire RX and TX with TX last so we're ready to read! */
+ dmaengine_submit(rxdesc);
+ dmaengine_submit(txdesc);
+ dma_async_issue_pending(rxchan);
+ dma_async_issue_pending(txchan);
+ pl022->dma_running = true;
+
+ return 0;
+
+err_txdesc:
+ dmaengine_terminate_all(txchan);
+err_rxdesc:
+ dmaengine_terminate_all(rxchan);
+ dma_unmap_sg(txchan->device->dev, pl022->sgt_tx.sgl,
+ pl022->sgt_tx.nents, DMA_TO_DEVICE);
+err_tx_sgmap:
+ dma_unmap_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
+ pl022->sgt_rx.nents, DMA_FROM_DEVICE);
+err_rx_sgmap:
+ sg_free_table(&pl022->sgt_tx);
+err_alloc_tx_sg:
+ sg_free_table(&pl022->sgt_rx);
+err_alloc_rx_sg:
+ return -ENOMEM;
+}
+
+static int pl022_dma_probe(struct pl022 *pl022)
+{
+ dma_cap_mask_t mask;
+
+ /* Try to acquire a generic DMA engine slave channel */
+ dma_cap_zero(mask);
+ dma_cap_set(DMA_SLAVE, mask);
+ /*
+ * We need both RX and TX channels to do DMA, else do none
+ * of them.
+ */
+ pl022->dma_rx_channel = dma_request_channel(mask,
+ pl022->master_info->dma_filter,
+ pl022->master_info->dma_rx_param);
+ if (!pl022->dma_rx_channel) {
+ dev_dbg(&pl022->adev->dev, "no RX DMA channel!\n");
+ goto err_no_rxchan;
+ }
+
+ pl022->dma_tx_channel = dma_request_channel(mask,
+ pl022->master_info->dma_filter,
+ pl022->master_info->dma_tx_param);
+ if (!pl022->dma_tx_channel) {
+ dev_dbg(&pl022->adev->dev, "no TX DMA channel!\n");
+ goto err_no_txchan;
+ }
+
+ pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!pl022->dummypage)
+ goto err_no_dummypage;
+
+ dev_info(&pl022->adev->dev, "setup for DMA on RX %s, TX %s\n",
+ dma_chan_name(pl022->dma_rx_channel),
+ dma_chan_name(pl022->dma_tx_channel));
+
+ return 0;
+
+err_no_dummypage:
+ dma_release_channel(pl022->dma_tx_channel);
+err_no_txchan:
+ dma_release_channel(pl022->dma_rx_channel);
+ pl022->dma_rx_channel = NULL;
+err_no_rxchan:
+ dev_err(&pl022->adev->dev,
+ "Failed to work in dma mode, work without dma!\n");
+ return -ENODEV;
+}
+
+static int pl022_dma_autoprobe(struct pl022 *pl022)
+{
+ struct device *dev = &pl022->adev->dev;
+
+ /* automatically configure DMA channels from platform, normally using DT */
+ pl022->dma_rx_channel = dma_request_slave_channel(dev, "rx");
+ if (!pl022->dma_rx_channel)
+ goto err_no_rxchan;
+
+ pl022->dma_tx_channel = dma_request_slave_channel(dev, "tx");
+ if (!pl022->dma_tx_channel)
+ goto err_no_txchan;
+
+ pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!pl022->dummypage)
+ goto err_no_dummypage;
+
+ return 0;
+
+err_no_dummypage:
+ dma_release_channel(pl022->dma_tx_channel);
+ pl022->dma_tx_channel = NULL;
+err_no_txchan:
+ dma_release_channel(pl022->dma_rx_channel);
+ pl022->dma_rx_channel = NULL;
+err_no_rxchan:
+ return -ENODEV;
+}
+
+static void terminate_dma(struct pl022 *pl022)
+{
+ struct dma_chan *rxchan = pl022->dma_rx_channel;
+ struct dma_chan *txchan = pl022->dma_tx_channel;
+
+ dmaengine_terminate_all(rxchan);
+ dmaengine_terminate_all(txchan);
+ unmap_free_dma_scatter(pl022);
+ pl022->dma_running = false;
+}
+
+static void pl022_dma_remove(struct pl022 *pl022)
+{
+ if (pl022->dma_running)
+ terminate_dma(pl022);
+ if (pl022->dma_tx_channel)
+ dma_release_channel(pl022->dma_tx_channel);
+ if (pl022->dma_rx_channel)
+ dma_release_channel(pl022->dma_rx_channel);
+ kfree(pl022->dummypage);
+}
+
+#else
+static inline int configure_dma(struct pl022 *pl022)
+{
+ return -ENODEV;
+}
+
+static inline int pl022_dma_autoprobe(struct pl022 *pl022)
+{
+ return 0;
+}
+
+static inline int pl022_dma_probe(struct pl022 *pl022)
+{
+ return 0;
+}
+
+static inline void pl022_dma_remove(struct pl022 *pl022)
+{
+}
+#endif
+
+/**
+ * pl022_interrupt_handler - Interrupt handler for SSP controller
+ *
+ * This function handles interrupts generated for an interrupt based transfer.
+ * If a receive overrun (ROR) interrupt is there then we disable SSP, flag the
+ * current message's state as STATE_ERROR and schedule the tasklet
+ * pump_transfers which will do the postprocessing of the current message by
+ * calling giveback(). Otherwise it reads data from RX FIFO till there is no
+ * more data, and writes data in TX FIFO till it is not full. If we complete
+ * the transfer we move to the next transfer and schedule the tasklet.
+ */
+static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id)
+{
+ struct pl022 *pl022 = dev_id;
+ struct spi_message *msg = pl022->cur_msg;
+ u16 irq_status = 0;
+
+ if (unlikely(!msg)) {
+ dev_err(&pl022->adev->dev,
+ "bad message state in interrupt handler");
+ /* Never fail */
+ return IRQ_HANDLED;
+ }
+
+ /* Read the Interrupt Status Register */
+ irq_status = readw(SSP_MIS(pl022->virtbase));
+
+ if (unlikely(!irq_status))
+ return IRQ_NONE;
+
+ /*
+ * This handles the FIFO interrupts, the timeout
+ * interrupts are flatly ignored, they cannot be
+ * trusted.
+ */
+ if (unlikely(irq_status & SSP_MIS_MASK_RORMIS)) {
+ /*
+ * Overrun interrupt - bail out since our Data has been
+ * corrupted
+ */
+ dev_err(&pl022->adev->dev, "FIFO overrun\n");
+ if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RFF)
+ dev_err(&pl022->adev->dev,
+ "RXFIFO is full\n");
+
+ /*
+ * Disable and clear interrupts, disable SSP,
+ * mark message with bad status so it can be
+ * retried.
+ */
+ writew(DISABLE_ALL_INTERRUPTS,
+ SSP_IMSC(pl022->virtbase));
+ writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
+ writew((readw(SSP_CR1(pl022->virtbase)) &
+ (~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
+ msg->state = STATE_ERROR;
+
+ /* Schedule message queue handler */
+ tasklet_schedule(&pl022->pump_transfers);
+ return IRQ_HANDLED;
+ }
+
+ readwriter(pl022);
+
+ if (pl022->tx == pl022->tx_end) {
+ /* Disable Transmit interrupt, enable receive interrupt */
+ writew((readw(SSP_IMSC(pl022->virtbase)) &
+ ~SSP_IMSC_MASK_TXIM) | SSP_IMSC_MASK_RXIM,
+ SSP_IMSC(pl022->virtbase));
+ }
+
+ /*
+ * Since all transactions must write as much as shall be read,
+ * we can conclude the entire transaction once RX is complete.
+ * At this point, all TX will always be finished.
+ */
+ if (pl022->rx >= pl022->rx_end) {
+ writew(DISABLE_ALL_INTERRUPTS,
+ SSP_IMSC(pl022->virtbase));
+ writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
+ if (unlikely(pl022->rx > pl022->rx_end)) {
+ dev_warn(&pl022->adev->dev, "read %u surplus "
+ "bytes (did you request an odd "
+ "number of bytes on a 16bit bus?)\n",
+ (u32) (pl022->rx - pl022->rx_end));
+ }
+ /* Update total bytes transferred */
+ msg->actual_length += pl022->cur_transfer->len;
+ if (pl022->cur_transfer->cs_change)
+ pl022_cs_control(pl022, SSP_CHIP_DESELECT);
+ /* Move to next transfer */
+ msg->state = next_transfer(pl022);
+ tasklet_schedule(&pl022->pump_transfers);
+ return IRQ_HANDLED;
+ }
+
+ return IRQ_HANDLED;
+}
+
+/**
+ * This sets up the pointers to memory for the next message to
+ * send out on the SPI bus.
+ */
+static int set_up_next_transfer(struct pl022 *pl022,
+ struct spi_transfer *transfer)
+{
+ int residue;
+
+ /* Sanity check the message for this bus width */
+ residue = pl022->cur_transfer->len % pl022->cur_chip->n_bytes;
+ if (unlikely(residue != 0)) {
+ dev_err(&pl022->adev->dev,
+ "message of %u bytes to transmit but the current "
+ "chip bus has a data width of %u bytes!\n",
+ pl022->cur_transfer->len,
+ pl022->cur_chip->n_bytes);
+ dev_err(&pl022->adev->dev, "skipping this message\n");
+ return -EIO;
+ }
+ pl022->tx = (void *)transfer->tx_buf;
+ pl022->tx_end = pl022->tx + pl022->cur_transfer->len;
+ pl022->rx = (void *)transfer->rx_buf;
+ pl022->rx_end = pl022->rx + pl022->cur_transfer->len;
+ pl022->write =
+ pl022->tx ? pl022->cur_chip->write : WRITING_NULL;
+ pl022->read = pl022->rx ? pl022->cur_chip->read : READING_NULL;
+ return 0;
+}
+
+/**
+ * pump_transfers - Tasklet function which schedules next transfer
+ * when running in interrupt or DMA transfer mode.
+ * @data: SSP driver private data structure
+ *
+ */
+static void pump_transfers(unsigned long data)
+{
+ struct pl022 *pl022 = (struct pl022 *) data;
+ struct spi_message *message = NULL;
+ struct spi_transfer *transfer = NULL;
+ struct spi_transfer *previous = NULL;
+
+ /* Get current state information */
+ message = pl022->cur_msg;
+ transfer = pl022->cur_transfer;
+
+ /* Handle for abort */
+ if (message->state == STATE_ERROR) {
+ message->status = -EIO;
+ giveback(pl022);
+ return;
+ }
+
+ /* Handle end of message */
+ if (message->state == STATE_DONE) {
+ message->status = 0;
+ giveback(pl022);
+ return;
+ }
+
+ /* Delay if requested at end of transfer before CS change */
+ if (message->state == STATE_RUNNING) {
+ previous = list_entry(transfer->transfer_list.prev,
+ struct spi_transfer,
+ transfer_list);
+ if (previous->delay_usecs)
+ /*
+ * FIXME: This runs in interrupt context.
+ * Is this really smart?
+ */
+ udelay(previous->delay_usecs);
+
+ /* Reselect chip select only if cs_change was requested */
+ if (previous->cs_change)
+ pl022_cs_control(pl022, SSP_CHIP_SELECT);
+ } else {
+ /* STATE_START */
+ message->state = STATE_RUNNING;
+ }
+
+ if (set_up_next_transfer(pl022, transfer)) {
+ message->state = STATE_ERROR;
+ message->status = -EIO;
+ giveback(pl022);
+ return;
+ }
+ /* Flush the FIFOs and let's go! */
+ flush(pl022);
+
+ if (pl022->cur_chip->enable_dma) {
+ if (configure_dma(pl022)) {
+ dev_dbg(&pl022->adev->dev,
+ "configuration of DMA failed, fall back to interrupt mode\n");
+ goto err_config_dma;
+ }
+ return;
+ }
+
+err_config_dma:
+ /* enable all interrupts except RX */
+ writew(ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM, SSP_IMSC(pl022->virtbase));
+}
+
+static void do_interrupt_dma_transfer(struct pl022 *pl022)
+{
+ /*
+ * Default is to enable all interrupts except RX -
+ * this will be enabled once TX is complete
+ */
+ u32 irqflags = (u32)(ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM);
+
+ /* Enable target chip, if not already active */
+ if (!pl022->next_msg_cs_active)
+ pl022_cs_control(pl022, SSP_CHIP_SELECT);
+
+ if (set_up_next_transfer(pl022, pl022->cur_transfer)) {
+ /* Error path */
+ pl022->cur_msg->state = STATE_ERROR;
+ pl022->cur_msg->status = -EIO;
+ giveback(pl022);
+ return;
+ }
+ /* If we're using DMA, set up DMA here */
+ if (pl022->cur_chip->enable_dma) {
+ /* Configure DMA transfer */
+ if (configure_dma(pl022)) {
+ dev_dbg(&pl022->adev->dev,
+ "configuration of DMA failed, fall back to interrupt mode\n");
+ goto err_config_dma;
+ }
+ /* Disable interrupts in DMA mode, IRQ from DMA controller */
+ irqflags = DISABLE_ALL_INTERRUPTS;
+ }
+err_config_dma:
+ /* Enable SSP, turn on interrupts */
+ writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
+ SSP_CR1(pl022->virtbase));
+ writew(irqflags, SSP_IMSC(pl022->virtbase));
+}
+
+static void do_polling_transfer(struct pl022 *pl022)
+{
+ struct spi_message *message = NULL;
+ struct spi_transfer *transfer = NULL;
+ struct spi_transfer *previous = NULL;
+ struct chip_data *chip;
+ unsigned long time, timeout;
+
+ chip = pl022->cur_chip;
+ message = pl022->cur_msg;
+
+ while (message->state != STATE_DONE) {
+ /* Handle for abort */
+ if (message->state == STATE_ERROR)
+ break;
+ transfer = pl022->cur_transfer;
+
+ /* Delay if requested at end of transfer */
+ if (message->state == STATE_RUNNING) {
+ previous =
+ list_entry(transfer->transfer_list.prev,
+ struct spi_transfer, transfer_list);
+ if (previous->delay_usecs)
+ udelay(previous->delay_usecs);
+ if (previous->cs_change)
+ pl022_cs_control(pl022, SSP_CHIP_SELECT);
+ } else {
+ /* STATE_START */
+ message->state = STATE_RUNNING;
+ if (!pl022->next_msg_cs_active)
+ pl022_cs_control(pl022, SSP_CHIP_SELECT);
+ }
+
+ /* Configuration Changing Per Transfer */
+ if (set_up_next_transfer(pl022, transfer)) {
+ /* Error path */
+ message->state = STATE_ERROR;
+ break;
+ }
+ /* Flush FIFOs and enable SSP */
+ flush(pl022);
+ writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
+ SSP_CR1(pl022->virtbase));
+
+ dev_dbg(&pl022->adev->dev, "polling transfer ongoing ...\n");
+
+ timeout = jiffies + msecs_to_jiffies(SPI_POLLING_TIMEOUT);
+ while (pl022->tx < pl022->tx_end || pl022->rx < pl022->rx_end) {
+ time = jiffies;
+ readwriter(pl022);
+ if (time_after(time, timeout)) {
+ dev_warn(&pl022->adev->dev,
+ "%s: timeout!\n", __func__);
+ message->state = STATE_ERROR;
+ goto out;
+ }
+ cpu_relax();
+ }
+
+ /* Update total byte transferred */
+ message->actual_length += pl022->cur_transfer->len;
+ if (pl022->cur_transfer->cs_change)
+ pl022_cs_control(pl022, SSP_CHIP_DESELECT);
+ /* Move to next transfer */
+ message->state = next_transfer(pl022);
+ }
+out:
+ /* Handle end of message */
+ if (message->state == STATE_DONE)
+ message->status = 0;
+ else
+ message->status = -EIO;
+
+ giveback(pl022);
+ return;
+}
+
+static int pl022_transfer_one_message(struct spi_master *master,
+ struct spi_message *msg)
+{
+ struct pl022 *pl022 = spi_master_get_devdata(master);
+
+ /* Initial message state */
+ pl022->cur_msg = msg;
+ msg->state = STATE_START;
+
+ pl022->cur_transfer = list_entry(msg->transfers.next,
+ struct spi_transfer, transfer_list);
+
+ /* Setup the SPI using the per chip configuration */
+ pl022->cur_chip = spi_get_ctldata(msg->spi);
+ pl022->cur_cs = pl022->chipselects[msg->spi->chip_select];
+
+ restore_state(pl022);
+ flush(pl022);
+
+ if (pl022->cur_chip->xfer_type == POLLING_TRANSFER)
+ do_polling_transfer(pl022);
+ else
+ do_interrupt_dma_transfer(pl022);
+
+ return 0;
+}
+
+static int pl022_unprepare_transfer_hardware(struct spi_master *master)
+{
+ struct pl022 *pl022 = spi_master_get_devdata(master);
+
+ /* nothing more to do - disable spi/ssp and power off */
+ writew((readw(SSP_CR1(pl022->virtbase)) &
+ (~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
+
+ return 0;
+}
+
+static int verify_controller_parameters(struct pl022 *pl022,
+ struct pl022_config_chip const *chip_info)
+{
+ if ((chip_info->iface < SSP_INTERFACE_MOTOROLA_SPI)
+ || (chip_info->iface > SSP_INTERFACE_UNIDIRECTIONAL)) {
+ dev_err(&pl022->adev->dev,
+ "interface is configured incorrectly\n");
+ return -EINVAL;
+ }
+ if ((chip_info->iface == SSP_INTERFACE_UNIDIRECTIONAL) &&
+ (!pl022->vendor->unidir)) {
+ dev_err(&pl022->adev->dev,
+ "unidirectional mode not supported in this "
+ "hardware version\n");
+ return -EINVAL;
+ }
+ if ((chip_info->hierarchy != SSP_MASTER)
+ && (chip_info->hierarchy != SSP_SLAVE)) {
+ dev_err(&pl022->adev->dev,
+ "hierarchy is configured incorrectly\n");
+ return -EINVAL;
+ }
+ if ((chip_info->com_mode != INTERRUPT_TRANSFER)
+ && (chip_info->com_mode != DMA_TRANSFER)
+ && (chip_info->com_mode != POLLING_TRANSFER)) {
+ dev_err(&pl022->adev->dev,
+ "Communication mode is configured incorrectly\n");
+ return -EINVAL;
+ }
+ switch (chip_info->rx_lev_trig) {
+ case SSP_RX_1_OR_MORE_ELEM:
+ case SSP_RX_4_OR_MORE_ELEM:
+ case SSP_RX_8_OR_MORE_ELEM:
+ /* These are always OK, all variants can handle this */
+ break;
+ case SSP_RX_16_OR_MORE_ELEM:
+ if (pl022->vendor->fifodepth < 16) {
+ dev_err(&pl022->adev->dev,
+ "RX FIFO Trigger Level is configured incorrectly\n");
+ return -EINVAL;
+ }
+ break;
+ case SSP_RX_32_OR_MORE_ELEM:
+ if (pl022->vendor->fifodepth < 32) {
+ dev_err(&pl022->adev->dev,
+ "RX FIFO Trigger Level is configured incorrectly\n");
+ return -EINVAL;
+ }
+ break;
+ default:
+ dev_err(&pl022->adev->dev,
+ "RX FIFO Trigger Level is configured incorrectly\n");
+ return -EINVAL;
+ }
+ switch (chip_info->tx_lev_trig) {
+ case SSP_TX_1_OR_MORE_EMPTY_LOC:
+ case SSP_TX_4_OR_MORE_EMPTY_LOC:
+ case SSP_TX_8_OR_MORE_EMPTY_LOC:
+ /* These are always OK, all variants can handle this */
+ break;
+ case SSP_TX_16_OR_MORE_EMPTY_LOC:
+ if (pl022->vendor->fifodepth < 16) {
+ dev_err(&pl022->adev->dev,
+ "TX FIFO Trigger Level is configured incorrectly\n");
+ return -EINVAL;
+ }
+ break;
+ case SSP_TX_32_OR_MORE_EMPTY_LOC:
+ if (pl022->vendor->fifodepth < 32) {
+ dev_err(&pl022->adev->dev,
+ "TX FIFO Trigger Level is configured incorrectly\n");
+ return -EINVAL;
+ }
+ break;
+ default:
+ dev_err(&pl022->adev->dev,
+ "TX FIFO Trigger Level is configured incorrectly\n");
+ return -EINVAL;
+ }
+ if (chip_info->iface == SSP_INTERFACE_NATIONAL_MICROWIRE) {
+ if ((chip_info->ctrl_len < SSP_BITS_4)
+ || (chip_info->ctrl_len > SSP_BITS_32)) {
+ dev_err(&pl022->adev->dev,
+ "CTRL LEN is configured incorrectly\n");
+ return -EINVAL;
+ }
+ if ((chip_info->wait_state != SSP_MWIRE_WAIT_ZERO)
+ && (chip_info->wait_state != SSP_MWIRE_WAIT_ONE)) {
+ dev_err(&pl022->adev->dev,
+ "Wait State is configured incorrectly\n");
+ return -EINVAL;
+ }
+ /* Half duplex is only available in the ST Micro version */
+ if (pl022->vendor->extended_cr) {
+ if ((chip_info->duplex !=
+ SSP_MICROWIRE_CHANNEL_FULL_DUPLEX)
+ && (chip_info->duplex !=
+ SSP_MICROWIRE_CHANNEL_HALF_DUPLEX)) {
+ dev_err(&pl022->adev->dev,
+ "Microwire duplex mode is configured incorrectly\n");
+ return -EINVAL;
+ }
+ } else {
+ if (chip_info->duplex != SSP_MICROWIRE_CHANNEL_FULL_DUPLEX)
+ dev_err(&pl022->adev->dev,
+ "Microwire half duplex mode requested,"
+ " but this is only available in the"
+ " ST version of PL022\n");
+ return -EINVAL;
+ }
+ }
+ return 0;
+}
+
+static inline u32 spi_rate(u32 rate, u16 cpsdvsr, u16 scr)
+{
+ return rate / (cpsdvsr * (1 + scr));
+}
+
+static int calculate_effective_freq(struct pl022 *pl022, int freq, struct
+ ssp_clock_params * clk_freq)
+{
+ /* Lets calculate the frequency parameters */
+ u16 cpsdvsr = CPSDVR_MIN, scr = SCR_MIN;
+ u32 rate, max_tclk, min_tclk, best_freq = 0, best_cpsdvsr = 0,
+ best_scr = 0, tmp, found = 0;
+
+ rate = clk_get_rate(pl022->clk);
+ /* cpsdvscr = 2 & scr 0 */
+ max_tclk = spi_rate(rate, CPSDVR_MIN, SCR_MIN);
+ /* cpsdvsr = 254 & scr = 255 */
+ min_tclk = spi_rate(rate, CPSDVR_MAX, SCR_MAX);
+
+ if (freq > max_tclk)
+ dev_warn(&pl022->adev->dev,
+ "Max speed that can be programmed is %d Hz, you requested %d\n",
+ max_tclk, freq);
+
+ if (freq < min_tclk) {
+ dev_err(&pl022->adev->dev,
+ "Requested frequency: %d Hz is less than minimum possible %d Hz\n",
+ freq, min_tclk);
+ return -EINVAL;
+ }
+
+ /*
+ * best_freq will give closest possible available rate (<= requested
+ * freq) for all values of scr & cpsdvsr.
+ */
+ while ((cpsdvsr <= CPSDVR_MAX) && !found) {
+ while (scr <= SCR_MAX) {
+ tmp = spi_rate(rate, cpsdvsr, scr);
+
+ if (tmp > freq) {
+ /* we need lower freq */
+ scr++;
+ continue;
+ }
+
+ /*
+ * If found exact value, mark found and break.
+ * If found more closer value, update and break.
+ */
+ if (tmp > best_freq) {
+ best_freq = tmp;
+ best_cpsdvsr = cpsdvsr;
+ best_scr = scr;
+
+ if (tmp == freq)
+ found = 1;
+ }
+ /*
+ * increased scr will give lower rates, which are not
+ * required
+ */
+ break;
+ }
+ cpsdvsr += 2;
+ scr = SCR_MIN;
+ }
+
+ WARN(!best_freq, "pl022: Matching cpsdvsr and scr not found for %d Hz rate \n",
+ freq);
+
+ clk_freq->cpsdvsr = (u8) (best_cpsdvsr & 0xFF);
+ clk_freq->scr = (u8) (best_scr & 0xFF);
+ dev_dbg(&pl022->adev->dev,
+ "SSP Target Frequency is: %u, Effective Frequency is %u\n",
+ freq, best_freq);
+ dev_dbg(&pl022->adev->dev, "SSP cpsdvsr = %d, scr = %d\n",
+ clk_freq->cpsdvsr, clk_freq->scr);
+
+ return 0;
+}
+
+/*
+ * A piece of default chip info unless the platform
+ * supplies it.
+ */
+static const struct pl022_config_chip pl022_default_chip_info = {
+ .com_mode = POLLING_TRANSFER,
+ .iface = SSP_INTERFACE_MOTOROLA_SPI,
+ .hierarchy = SSP_SLAVE,
+ .slave_tx_disable = DO_NOT_DRIVE_TX,
+ .rx_lev_trig = SSP_RX_1_OR_MORE_ELEM,
+ .tx_lev_trig = SSP_TX_1_OR_MORE_EMPTY_LOC,
+ .ctrl_len = SSP_BITS_8,
+ .wait_state = SSP_MWIRE_WAIT_ZERO,
+ .duplex = SSP_MICROWIRE_CHANNEL_FULL_DUPLEX,
+ .cs_control = null_cs_control,
+};
+
+/**
+ * pl022_setup - setup function registered to SPI master framework
+ * @spi: spi device which is requesting setup
+ *
+ * This function is registered to the SPI framework for this SPI master
+ * controller. If it is the first time when setup is called by this device,
+ * this function will initialize the runtime state for this chip and save
+ * the same in the device structure. Else it will update the runtime info
+ * with the updated chip info. Nothing is really being written to the
+ * controller hardware here, that is not done until the actual transfer
+ * commence.
+ */
+static int pl022_setup(struct spi_device *spi)
+{
+ struct pl022_config_chip const *chip_info;
+ struct pl022_config_chip chip_info_dt;
+ struct chip_data *chip;
+ struct ssp_clock_params clk_freq = { .cpsdvsr = 0, .scr = 0};
+ int status = 0;
+ struct pl022 *pl022 = spi_master_get_devdata(spi->master);
+ unsigned int bits = spi->bits_per_word;
+ u32 tmp;
+ struct device_node *np = spi->dev.of_node;
+
+ if (!spi->max_speed_hz)
+ return -EINVAL;
+
+ /* Get controller_state if one is supplied */
+ chip = spi_get_ctldata(spi);
+
+ if (chip == NULL) {
+ chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
+ if (!chip)
+ return -ENOMEM;
+ dev_dbg(&spi->dev,
+ "allocated memory for controller's runtime state\n");
+ }
+
+ /* Get controller data if one is supplied */
+ chip_info = spi->controller_data;
+
+ if (chip_info == NULL) {
+ if (np) {
+ chip_info_dt = pl022_default_chip_info;
+
+ chip_info_dt.hierarchy = SSP_MASTER;
+ of_property_read_u32(np, "pl022,interface",
+ &chip_info_dt.iface);
+ of_property_read_u32(np, "pl022,com-mode",
+ &chip_info_dt.com_mode);
+ of_property_read_u32(np, "pl022,rx-level-trig",
+ &chip_info_dt.rx_lev_trig);
+ of_property_read_u32(np, "pl022,tx-level-trig",
+ &chip_info_dt.tx_lev_trig);
+ of_property_read_u32(np, "pl022,ctrl-len",
+ &chip_info_dt.ctrl_len);
+ of_property_read_u32(np, "pl022,wait-state",
+ &chip_info_dt.wait_state);
+ of_property_read_u32(np, "pl022,duplex",
+ &chip_info_dt.duplex);
+
+ chip_info = &chip_info_dt;
+ } else {
+ chip_info = &pl022_default_chip_info;
+ /* spi_board_info.controller_data not is supplied */
+ dev_dbg(&spi->dev,
+ "using default controller_data settings\n");
+ }
+ } else
+ dev_dbg(&spi->dev,
+ "using user supplied controller_data settings\n");
+
+ /*
+ * We can override with custom divisors, else we use the board
+ * frequency setting
+ */
+ if ((0 == chip_info->clk_freq.cpsdvsr)
+ && (0 == chip_info->clk_freq.scr)) {
+ status = calculate_effective_freq(pl022,
+ spi->max_speed_hz,
+ &clk_freq);
+ if (status < 0)
+ goto err_config_params;
+ } else {
+ memcpy(&clk_freq, &chip_info->clk_freq, sizeof(clk_freq));
+ if ((clk_freq.cpsdvsr % 2) != 0)
+ clk_freq.cpsdvsr =
+ clk_freq.cpsdvsr - 1;
+ }
+ if ((clk_freq.cpsdvsr < CPSDVR_MIN)
+ || (clk_freq.cpsdvsr > CPSDVR_MAX)) {
+ status = -EINVAL;
+ dev_err(&spi->dev,
+ "cpsdvsr is configured incorrectly\n");
+ goto err_config_params;
+ }
+
+ status = verify_controller_parameters(pl022, chip_info);
+ if (status) {
+ dev_err(&spi->dev, "controller data is incorrect");
+ goto err_config_params;
+ }
+
+ pl022->rx_lev_trig = chip_info->rx_lev_trig;
+ pl022->tx_lev_trig = chip_info->tx_lev_trig;
+
+ /* Now set controller state based on controller data */
+ chip->xfer_type = chip_info->com_mode;
+ if (!chip_info->cs_control) {
+ chip->cs_control = null_cs_control;
+ if (!gpio_is_valid(pl022->chipselects[spi->chip_select]))
+ dev_warn(&spi->dev,
+ "invalid chip select\n");
+ } else
+ chip->cs_control = chip_info->cs_control;
+
+ /* Check bits per word with vendor specific range */
+ if ((bits <= 3) || (bits > pl022->vendor->max_bpw)) {
+ status = -ENOTSUPP;
+ dev_err(&spi->dev, "illegal data size for this controller!\n");
+ dev_err(&spi->dev, "This controller can only handle 4 <= n <= %d bit words\n",
+ pl022->vendor->max_bpw);
+ goto err_config_params;
+ } else if (bits <= 8) {
+ dev_dbg(&spi->dev, "4 <= n <=8 bits per word\n");
+ chip->n_bytes = 1;
+ chip->read = READING_U8;
+ chip->write = WRITING_U8;
+ } else if (bits <= 16) {
+ dev_dbg(&spi->dev, "9 <= n <= 16 bits per word\n");
+ chip->n_bytes = 2;
+ chip->read = READING_U16;
+ chip->write = WRITING_U16;
+ } else {
+ dev_dbg(&spi->dev, "17 <= n <= 32 bits per word\n");
+ chip->n_bytes = 4;
+ chip->read = READING_U32;
+ chip->write = WRITING_U32;
+ }
+
+ /* Now Initialize all register settings required for this chip */
+ chip->cr0 = 0;
+ chip->cr1 = 0;
+ chip->dmacr = 0;
+ chip->cpsr = 0;
+ if ((chip_info->com_mode == DMA_TRANSFER)
+ && ((pl022->master_info)->enable_dma)) {
+ chip->enable_dma = true;
+ dev_dbg(&spi->dev, "DMA mode set in controller state\n");
+ SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
+ SSP_DMACR_MASK_RXDMAE, 0);
+ SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
+ SSP_DMACR_MASK_TXDMAE, 1);
+ } else {
+ chip->enable_dma = false;
+ dev_dbg(&spi->dev, "DMA mode NOT set in controller state\n");
+ SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
+ SSP_DMACR_MASK_RXDMAE, 0);
+ SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
+ SSP_DMACR_MASK_TXDMAE, 1);
+ }
+
+ chip->cpsr = clk_freq.cpsdvsr;
+
+ /* Special setup for the ST micro extended control registers */
+ if (pl022->vendor->extended_cr) {
+ u32 etx;
+
+ if (pl022->vendor->pl023) {
+ /* These bits are only in the PL023 */
+ SSP_WRITE_BITS(chip->cr1, chip_info->clkdelay,
+ SSP_CR1_MASK_FBCLKDEL_ST, 13);
+ } else {
+ /* These bits are in the PL022 but not PL023 */
+ SSP_WRITE_BITS(chip->cr0, chip_info->duplex,
+ SSP_CR0_MASK_HALFDUP_ST, 5);
+ SSP_WRITE_BITS(chip->cr0, chip_info->ctrl_len,
+ SSP_CR0_MASK_CSS_ST, 16);
+ SSP_WRITE_BITS(chip->cr0, chip_info->iface,
+ SSP_CR0_MASK_FRF_ST, 21);
+ SSP_WRITE_BITS(chip->cr1, chip_info->wait_state,
+ SSP_CR1_MASK_MWAIT_ST, 6);
+ }
+ SSP_WRITE_BITS(chip->cr0, bits - 1,
+ SSP_CR0_MASK_DSS_ST, 0);
+
+ if (spi->mode & SPI_LSB_FIRST) {
+ tmp = SSP_RX_LSB;
+ etx = SSP_TX_LSB;
+ } else {
+ tmp = SSP_RX_MSB;
+ etx = SSP_TX_MSB;
+ }
+ SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_RENDN_ST, 4);
+ SSP_WRITE_BITS(chip->cr1, etx, SSP_CR1_MASK_TENDN_ST, 5);
+ SSP_WRITE_BITS(chip->cr1, chip_info->rx_lev_trig,
+ SSP_CR1_MASK_RXIFLSEL_ST, 7);
+ SSP_WRITE_BITS(chip->cr1, chip_info->tx_lev_trig,
+ SSP_CR1_MASK_TXIFLSEL_ST, 10);
+ } else {
+ SSP_WRITE_BITS(chip->cr0, bits - 1,
+ SSP_CR0_MASK_DSS, 0);
+ SSP_WRITE_BITS(chip->cr0, chip_info->iface,
+ SSP_CR0_MASK_FRF, 4);
+ }
+
+ /* Stuff that is common for all versions */
+ if (spi->mode & SPI_CPOL)
+ tmp = SSP_CLK_POL_IDLE_HIGH;
+ else
+ tmp = SSP_CLK_POL_IDLE_LOW;
+ SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPO, 6);
+
+ if (spi->mode & SPI_CPHA)
+ tmp = SSP_CLK_SECOND_EDGE;
+ else
+ tmp = SSP_CLK_FIRST_EDGE;
+ SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPH, 7);
+
+ SSP_WRITE_BITS(chip->cr0, clk_freq.scr, SSP_CR0_MASK_SCR, 8);
+ /* Loopback is available on all versions except PL023 */
+ if (pl022->vendor->loopback) {
+ if (spi->mode & SPI_LOOP)
+ tmp = LOOPBACK_ENABLED;
+ else
+ tmp = LOOPBACK_DISABLED;
+ SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_LBM, 0);
+ }
+ SSP_WRITE_BITS(chip->cr1, SSP_DISABLED, SSP_CR1_MASK_SSE, 1);
+ SSP_WRITE_BITS(chip->cr1, chip_info->hierarchy, SSP_CR1_MASK_MS, 2);
+ SSP_WRITE_BITS(chip->cr1, chip_info->slave_tx_disable, SSP_CR1_MASK_SOD,
+ 3);
+
+ /* Save controller_state */
+ spi_set_ctldata(spi, chip);
+ return status;
+ err_config_params:
+ spi_set_ctldata(spi, NULL);
+ kfree(chip);
+ return status;
+}
+
+/**
+ * pl022_cleanup - cleanup function registered to SPI master framework
+ * @spi: spi device which is requesting cleanup
+ *
+ * This function is registered to the SPI framework for this SPI master
+ * controller. It will free the runtime state of chip.
+ */
+static void pl022_cleanup(struct spi_device *spi)
+{
+ struct chip_data *chip = spi_get_ctldata(spi);
+
+ spi_set_ctldata(spi, NULL);
+ kfree(chip);
+}
+
+static struct pl022_ssp_controller *
+pl022_platform_data_dt_get(struct device *dev)
+{
+ struct device_node *np = dev->of_node;
+ struct pl022_ssp_controller *pd;
+ u32 tmp;
+
+ if (!np) {
+ dev_err(dev, "no dt node defined\n");
+ return NULL;
+ }
+
+ pd = devm_kzalloc(dev, sizeof(struct pl022_ssp_controller), GFP_KERNEL);
+ if (!pd)
+ return NULL;
+
+ pd->bus_id = -1;
+ pd->enable_dma = 1;
+ of_property_read_u32(np, "num-cs", &tmp);
+ pd->num_chipselect = tmp;
+ of_property_read_u32(np, "pl022,autosuspend-delay",
+ &pd->autosuspend_delay);
+ pd->rt = of_property_read_bool(np, "pl022,rt");
+
+ return pd;
+}
+
+static int pl022_probe(struct amba_device *adev, const struct amba_id *id)
+{
+ struct device *dev = &adev->dev;
+ struct pl022_ssp_controller *platform_info =
+ dev_get_platdata(&adev->dev);
+ struct spi_master *master;
+ struct pl022 *pl022 = NULL; /*Data for this driver */
+ struct device_node *np = adev->dev.of_node;
+ int status = 0, i, num_cs;
+
+ dev_info(&adev->dev,
+ "ARM PL022 driver, device ID: 0x%08x\n", adev->periphid);
+ if (!platform_info && IS_ENABLED(CONFIG_OF))
+ platform_info = pl022_platform_data_dt_get(dev);
+
+ if (!platform_info) {
+ dev_err(dev, "probe: no platform data defined\n");
+ return -ENODEV;
+ }
+
+ if (platform_info->num_chipselect) {
+ num_cs = platform_info->num_chipselect;
+ } else {
+ dev_err(dev, "probe: no chip select defined\n");
+ return -ENODEV;
+ }
+
+ /* Allocate master with space for data */
+ master = spi_alloc_master(dev, sizeof(struct pl022));
+ if (master == NULL) {
+ dev_err(&adev->dev, "probe - cannot alloc SPI master\n");
+ return -ENOMEM;
+ }
+
+ pl022 = spi_master_get_devdata(master);
+ pl022->master = master;
+ pl022->master_info = platform_info;
+ pl022->adev = adev;
+ pl022->vendor = id->data;
+ pl022->chipselects = devm_kzalloc(dev, num_cs * sizeof(int),
+ GFP_KERNEL);
+ if (!pl022->chipselects) {
+ status = -ENOMEM;
+ goto err_no_mem;
+ }
+
+ /*
+ * Bus Number Which has been Assigned to this SSP controller
+ * on this board
+ */
+ master->bus_num = platform_info->bus_id;
+ master->num_chipselect = num_cs;
+ master->cleanup = pl022_cleanup;
+ master->setup = pl022_setup;
+ master->auto_runtime_pm = true;
+ master->transfer_one_message = pl022_transfer_one_message;
+ master->unprepare_transfer_hardware = pl022_unprepare_transfer_hardware;
+ master->rt = platform_info->rt;
+ master->dev.of_node = dev->of_node;
+
+ if (platform_info->num_chipselect && platform_info->chipselects) {
+ for (i = 0; i < num_cs; i++)
+ pl022->chipselects[i] = platform_info->chipselects[i];
+ } else if (pl022->vendor->internal_cs_ctrl) {
+ for (i = 0; i < num_cs; i++)
+ pl022->chipselects[i] = i;
+ } else if (IS_ENABLED(CONFIG_OF)) {
+ for (i = 0; i < num_cs; i++) {
+ int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
+
+ if (cs_gpio == -EPROBE_DEFER) {
+ status = -EPROBE_DEFER;
+ goto err_no_gpio;
+ }
+
+ pl022->chipselects[i] = cs_gpio;
+
+ if (gpio_is_valid(cs_gpio)) {
+ if (devm_gpio_request(dev, cs_gpio, "ssp-pl022"))
+ dev_err(&adev->dev,
+ "could not request %d gpio\n",
+ cs_gpio);
+ else if (gpio_direction_output(cs_gpio, 1))
+ dev_err(&adev->dev,
+ "could not set gpio %d as output\n",
+ cs_gpio);
+ }
+ }
+ }
+
+ /*
+ * Supports mode 0-3, loopback, and active low CS. Transfers are
+ * always MS bit first on the original pl022.
+ */
+ master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LOOP;
+ if (pl022->vendor->extended_cr)
+ master->mode_bits |= SPI_LSB_FIRST;
+
+ dev_dbg(&adev->dev, "BUSNO: %d\n", master->bus_num);
+
+ status = amba_request_regions(adev, NULL);
+ if (status)
+ goto err_no_ioregion;
+
+ pl022->phybase = adev->res.start;
+ pl022->virtbase = devm_ioremap(dev, adev->res.start,
+ resource_size(&adev->res));
+ if (pl022->virtbase == NULL) {
+ status = -ENOMEM;
+ goto err_no_ioremap;
+ }
+ dev_info(&adev->dev, "mapped registers from %pa to %p\n",
+ &adev->res.start, pl022->virtbase);
+
+ pl022->clk = devm_clk_get(&adev->dev, NULL);
+ if (IS_ERR(pl022->clk)) {
+ status = PTR_ERR(pl022->clk);
+ dev_err(&adev->dev, "could not retrieve SSP/SPI bus clock\n");
+ goto err_no_clk;
+ }
+
+ status = clk_prepare_enable(pl022->clk);
+ if (status) {
+ dev_err(&adev->dev, "could not enable SSP/SPI bus clock\n");
+ goto err_no_clk_en;
+ }
+
+ /* Initialize transfer pump */
+ tasklet_init(&pl022->pump_transfers, pump_transfers,
+ (unsigned long)pl022);
+
+ /* Disable SSP */
+ writew((readw(SSP_CR1(pl022->virtbase)) & (~SSP_CR1_MASK_SSE)),
+ SSP_CR1(pl022->virtbase));
+ load_ssp_default_config(pl022);
+
+ status = devm_request_irq(dev, adev->irq[0], pl022_interrupt_handler,
+ 0, "pl022", pl022);
+ if (status < 0) {
+ dev_err(&adev->dev, "probe - cannot get IRQ (%d)\n", status);
+ goto err_no_irq;
+ }
+
+ /* Get DMA channels, try autoconfiguration first */
+ status = pl022_dma_autoprobe(pl022);
+
+ /* If that failed, use channels from platform_info */
+ if (status == 0)
+ platform_info->enable_dma = 1;
+ else if (platform_info->enable_dma) {
+ status = pl022_dma_probe(pl022);
+ if (status != 0)
+ platform_info->enable_dma = 0;
+ }
+
+ /* Register with the SPI framework */
+ amba_set_drvdata(adev, pl022);
+ status = devm_spi_register_master(&adev->dev, master);
+ if (status != 0) {
+ dev_err(&adev->dev,
+ "probe - problem registering spi master\n");
+ goto err_spi_register;
+ }
+ dev_dbg(dev, "probe succeeded\n");
+
+ /* let runtime pm put suspend */
+ if (platform_info->autosuspend_delay > 0) {
+ dev_info(&adev->dev,
+ "will use autosuspend for runtime pm, delay %dms\n",
+ platform_info->autosuspend_delay);
+ pm_runtime_set_autosuspend_delay(dev,
+ platform_info->autosuspend_delay);
+ pm_runtime_use_autosuspend(dev);
+ }
+ pm_runtime_put(dev);
+
+ return 0;
+
+ err_spi_register:
+ if (platform_info->enable_dma)
+ pl022_dma_remove(pl022);
+ err_no_irq:
+ clk_disable_unprepare(pl022->clk);
+ err_no_clk_en:
+ err_no_clk:
+ err_no_ioremap:
+ amba_release_regions(adev);
+ err_no_ioregion:
+ err_no_gpio:
+ err_no_mem:
+ spi_master_put(master);
+ return status;
+}
+
+static int
+pl022_remove(struct amba_device *adev)
+{
+ struct pl022 *pl022 = amba_get_drvdata(adev);
+
+ if (!pl022)
+ return 0;
+
+ /*
+ * undo pm_runtime_put() in probe. I assume that we're not
+ * accessing the primecell here.
+ */
+ pm_runtime_get_noresume(&adev->dev);
+
+ load_ssp_default_config(pl022);
+ if (pl022->master_info->enable_dma)
+ pl022_dma_remove(pl022);
+
+ clk_disable_unprepare(pl022->clk);
+ amba_release_regions(adev);
+ tasklet_disable(&pl022->pump_transfers);
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int pl022_suspend(struct device *dev)
+{
+ struct pl022 *pl022 = dev_get_drvdata(dev);
+ int ret;
+
+ ret = spi_master_suspend(pl022->master);
+ if (ret) {
+ dev_warn(dev, "cannot suspend master\n");
+ return ret;
+ }
+
+ ret = pm_runtime_force_suspend(dev);
+ if (ret) {
+ spi_master_resume(pl022->master);
+ return ret;
+ }
+
+ pinctrl_pm_select_sleep_state(dev);
+
+ dev_dbg(dev, "suspended\n");
+ return 0;
+}
+
+static int pl022_resume(struct device *dev)
+{
+ struct pl022 *pl022 = dev_get_drvdata(dev);
+ int ret;
+
+ ret = pm_runtime_force_resume(dev);
+ if (ret)
+ dev_err(dev, "problem resuming\n");
+
+ /* Start the queue running */
+ ret = spi_master_resume(pl022->master);
+ if (ret)
+ dev_err(dev, "problem starting queue (%d)\n", ret);
+ else
+ dev_dbg(dev, "resumed\n");
+
+ return ret;
+}
+#endif
+
+#ifdef CONFIG_PM
+static int pl022_runtime_suspend(struct device *dev)
+{
+ struct pl022 *pl022 = dev_get_drvdata(dev);
+
+ clk_disable_unprepare(pl022->clk);
+ pinctrl_pm_select_idle_state(dev);
+
+ return 0;
+}
+
+static int pl022_runtime_resume(struct device *dev)
+{
+ struct pl022 *pl022 = dev_get_drvdata(dev);
+
+ pinctrl_pm_select_default_state(dev);
+ clk_prepare_enable(pl022->clk);
+
+ return 0;
+}
+#endif
+
+static const struct dev_pm_ops pl022_dev_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(pl022_suspend, pl022_resume)
+ SET_RUNTIME_PM_OPS(pl022_runtime_suspend, pl022_runtime_resume, NULL)
+};
+
+static struct vendor_data vendor_arm = {
+ .fifodepth = 8,
+ .max_bpw = 16,
+ .unidir = false,
+ .extended_cr = false,
+ .pl023 = false,
+ .loopback = true,
+ .internal_cs_ctrl = false,
+};
+
+static struct vendor_data vendor_st = {
+ .fifodepth = 32,
+ .max_bpw = 32,
+ .unidir = false,
+ .extended_cr = true,
+ .pl023 = false,
+ .loopback = true,
+ .internal_cs_ctrl = false,
+};
+
+static struct vendor_data vendor_st_pl023 = {
+ .fifodepth = 32,
+ .max_bpw = 32,
+ .unidir = false,
+ .extended_cr = true,
+ .pl023 = true,
+ .loopback = false,
+ .internal_cs_ctrl = false,
+};
+
+static struct vendor_data vendor_lsi = {
+ .fifodepth = 8,
+ .max_bpw = 16,
+ .unidir = false,
+ .extended_cr = false,
+ .pl023 = false,
+ .loopback = true,
+ .internal_cs_ctrl = true,
+};
+
+static struct amba_id pl022_ids[] = {
+ {
+ /*
+ * ARM PL022 variant, this has a 16bit wide
+ * and 8 locations deep TX/RX FIFO
+ */
+ .id = 0x00041022,
+ .mask = 0x000fffff,
+ .data = &vendor_arm,
+ },
+ {
+ /*
+ * ST Micro derivative, this has 32bit wide
+ * and 32 locations deep TX/RX FIFO
+ */
+ .id = 0x01080022,
+ .mask = 0xffffffff,
+ .data = &vendor_st,
+ },
+ {
+ /*
+ * ST-Ericsson derivative "PL023" (this is not
+ * an official ARM number), this is a PL022 SSP block
+ * stripped to SPI mode only, it has 32bit wide
+ * and 32 locations deep TX/RX FIFO but no extended
+ * CR0/CR1 register
+ */
+ .id = 0x00080023,
+ .mask = 0xffffffff,
+ .data = &vendor_st_pl023,
+ },
+ {
+ /*
+ * PL022 variant that has a chip select control register whih
+ * allows control of 5 output signals nCS[0:4].
+ */
+ .id = 0x000b6022,
+ .mask = 0x000fffff,
+ .data = &vendor_lsi,
+ },
+ { 0, 0 },
+};
+
+MODULE_DEVICE_TABLE(amba, pl022_ids);
+
+static struct amba_driver pl022_driver = {
+ .drv = {
+ .name = "ssp-pl022",
+ .pm = &pl022_dev_pm_ops,
+ },
+ .id_table = pl022_ids,
+ .probe = pl022_probe,
+ .remove = pl022_remove,
+};
+
+static int __init pl022_init(void)
+{
+ return amba_driver_register(&pl022_driver);
+}
+subsys_initcall(pl022_init);
+
+static void __exit pl022_exit(void)
+{
+ amba_driver_unregister(&pl022_driver);
+}
+module_exit(pl022_exit);
+
+MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
+MODULE_DESCRIPTION("PL022 SSP Controller Driver");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff