--- /dev/null
- unsigned char pha : 1; /* spim_clk Phase */
- unsigned char pol : 1; /* spim_clk Polarity */
- unsigned char epol : 1; /* spim_csx Polarity */
- unsigned char dpe : 1; /* Transmission Enable */
- unsigned char wl : 5; /* Word Length */
- unsigned char : 3;
- unsigned char trm : 2; /* TxRx Mode */
- unsigned char cs : 4; /* Chip Select */
- unsigned char wcnt : 7; /* Word Count */
- unsigned char ffen : 1; /* FIFO Enable */
- unsigned char spi_en : 1; /* SPI Enable */
- unsigned char : 5;
+ // SPDX-License-Identifier: GPL-2.0+
+ /*
+ * KP2000 SPI controller driver
+ *
+ * Copyright (C) 2014-2018 Daktronics
+ * Author: Matt Sickler <matt.sickler@daktronics.com>
+ * Very loosely based on spi-omap2-mcspi.c
+ */
+
+ #include <linux/kernel.h>
+ #include <linux/init.h>
+ #include <linux/interrupt.h>
+ #include <linux/io-64-nonatomic-lo-hi.h>
+ #include <linux/module.h>
+ #include <linux/device.h>
+ #include <linux/delay.h>
+ #include <linux/platform_device.h>
+ #include <linux/err.h>
+ #include <linux/clk.h>
+ #include <linux/io.h>
+ #include <linux/slab.h>
+ #include <linux/pm_runtime.h>
+ #include <linux/of.h>
+ #include <linux/of_device.h>
+ #include <linux/gcd.h>
+ #include <linux/spi/spi.h>
+ #include <linux/spi/flash.h>
+ #include <linux/mtd/partitions.h>
+
+ #include "../kpc.h"
+ #include "spi_parts.h"
+
+
+ /***************
+ * SPI Defines *
+ ***************/
+ #define KP_SPI_REG_CONFIG 0x0 /* 0x00 */
+ #define KP_SPI_REG_STATUS 0x1 /* 0x08 */
+ #define KP_SPI_REG_FFCTRL 0x2 /* 0x10 */
+ #define KP_SPI_REG_TXDATA 0x3 /* 0x18 */
+ #define KP_SPI_REG_RXDATA 0x4 /* 0x20 */
+
+ #define KP_SPI_CLK 48000000
+ #define KP_SPI_MAX_FIFODEPTH 64
+ #define KP_SPI_MAX_FIFOWCNT 0xFFFF
+
+ #define KP_SPI_REG_CONFIG_TRM_TXRX 0
+ #define KP_SPI_REG_CONFIG_TRM_RX 1
+ #define KP_SPI_REG_CONFIG_TRM_TX 2
+
+ #define KP_SPI_REG_STATUS_RXS 0x01
+ #define KP_SPI_REG_STATUS_TXS 0x02
+ #define KP_SPI_REG_STATUS_EOT 0x04
+ #define KP_SPI_REG_STATUS_TXFFE 0x10
+ #define KP_SPI_REG_STATUS_TXFFF 0x20
+ #define KP_SPI_REG_STATUS_RXFFE 0x40
+ #define KP_SPI_REG_STATUS_RXFFF 0x80
+
+
+
+ /******************
+ * SPI Structures *
+ ******************/
+ struct kp_spi {
+ struct spi_master *master;
+ u64 __iomem *base;
+ unsigned long phys;
+ struct device *dev;
+ int fifo_depth;
+ unsigned int pin_dir:1;
+ };
+
+
+ struct kp_spi_controller_state {
+ void __iomem *base;
+ unsigned long phys;
+ unsigned char chip_select;
+ int word_len;
+ s64 conf_cache;
+ };
+
+
+ union kp_spi_config {
+ /* use this to access individual elements */
+ struct __attribute__((packed)) spi_config_bitfield {
- unsigned char rx : 1; /* Rx Status */
- unsigned char tx : 1; /* Tx Status */
- unsigned char eo : 1; /* End of Transfer */
- unsigned char : 1;
- unsigned char txffe : 1; /* Tx FIFO Empty */
- unsigned char txfff : 1; /* Tx FIFO Full */
- unsigned char rxffe : 1; /* Rx FIFO Empty */
- unsigned char rxfff : 1; /* Rx FIFO Full */
- unsigned int : 24;
++ unsigned int pha : 1; /* spim_clk Phase */
++ unsigned int pol : 1; /* spim_clk Polarity */
++ unsigned int epol : 1; /* spim_csx Polarity */
++ unsigned int dpe : 1; /* Transmission Enable */
++ unsigned int wl : 5; /* Word Length */
++ unsigned int : 3;
++ unsigned int trm : 2; /* TxRx Mode */
++ unsigned int cs : 4; /* Chip Select */
++ unsigned int wcnt : 7; /* Word Count */
++ unsigned int ffen : 1; /* FIFO Enable */
++ unsigned int spi_en : 1; /* SPI Enable */
++ unsigned int : 5;
+ } bitfield;
+ /* use this to grab the whole register */
+ u32 reg;
+ };
+
+
+
+ union kp_spi_status {
+ struct __attribute__((packed)) spi_status_bitfield {
- unsigned char ffstart : 1; /* FIFO Start */
- unsigned int : 31;
++ unsigned int rx : 1; /* Rx Status */
++ unsigned int tx : 1; /* Tx Status */
++ unsigned int eo : 1; /* End of Transfer */
++ unsigned int : 1;
++ unsigned int txffe : 1; /* Tx FIFO Empty */
++ unsigned int txfff : 1; /* Tx FIFO Full */
++ unsigned int rxffe : 1; /* Rx FIFO Empty */
++ unsigned int rxfff : 1; /* Rx FIFO Full */
++ unsigned int : 24;
+ } bitfield;
+ u32 reg;
+ };
+
+
+
+ union kp_spi_ffctrl {
+ struct __attribute__((packed)) spi_ffctrl_bitfield {
++ unsigned int ffstart : 1; /* FIFO Start */
++ unsigned int : 31;
+ } bitfield;
+ u32 reg;
+ };
+
+
+
+ /***************
+ * SPI Helpers *
+ ***************/
+ static inline int
+ kp_spi_bytes_per_word(int word_len)
+ {
+ if (word_len <= 8){
+ return 1;
+ }
+ else if (word_len <= 16) {
+ return 2;
+ }
+ else { /* word_len <= 32 */
+ return 4;
+ }
+ }
+
+ static inline u64
+ kp_spi_read_reg(struct kp_spi_controller_state *cs, int idx)
+ {
+ u64 __iomem *addr = cs->base;
+ u64 val;
+
+ addr += idx;
+ if ((idx == KP_SPI_REG_CONFIG) && (cs->conf_cache >= 0)){
+ return cs->conf_cache;
+ }
+ val = readq((void*)addr);
+ return val;
+ }
+
+ static inline void
+ kp_spi_write_reg(struct kp_spi_controller_state *cs, int idx, u64 val)
+ {
+ u64 __iomem *addr = cs->base;
+ addr += idx;
+ writeq(val, (void*)addr);
+ if (idx == KP_SPI_REG_CONFIG)
+ cs->conf_cache = val;
+ }
+
+ static int
+ kp_spi_wait_for_reg_bit(struct kp_spi_controller_state *cs, int idx, unsigned long bit)
+ {
+ unsigned long timeout;
+ timeout = jiffies + msecs_to_jiffies(1000);
+ while (!(kp_spi_read_reg(cs, idx) & bit)) {
+ if (time_after(jiffies, timeout)) {
+ if (!(kp_spi_read_reg(cs, idx) & bit)) {
+ return -ETIMEDOUT;
+ } else {
+ return 0;
+ }
+ }
+ cpu_relax();
+ }
+ return 0;
+ }
+
+ static unsigned
+ kp_spi_txrx_pio(struct spi_device *spidev, struct spi_transfer *transfer)
+ {
+ struct kp_spi_controller_state *cs = spidev->controller_state;
+ unsigned int count = transfer->len;
+ unsigned int c = count;
+
+ int i;
+ u8 *rx = transfer->rx_buf;
+ const u8 *tx = transfer->tx_buf;
+ int processed = 0;
+
+ if (tx) {
+ for (i = 0 ; i < c ; i++) {
+ char val = *tx++;
+
+ if (kp_spi_wait_for_reg_bit(cs, KP_SPI_REG_STATUS, KP_SPI_REG_STATUS_TXS) < 0) {
+ goto out;
+ }
+
+ kp_spi_write_reg(cs, KP_SPI_REG_TXDATA, val);
+ processed++;
+ }
+ }
+ else if(rx) {
+ for (i = 0 ; i < c ; i++) {
+ char test=0;
+
+ kp_spi_write_reg(cs, KP_SPI_REG_TXDATA, 0x00);
+
+ if (kp_spi_wait_for_reg_bit(cs, KP_SPI_REG_STATUS, KP_SPI_REG_STATUS_RXS) < 0) {
+ goto out;
+ }
+
+ test = kp_spi_read_reg(cs, KP_SPI_REG_RXDATA);
+ *rx++ = test;
+ processed++;
+ }
+ }
+
+ if (kp_spi_wait_for_reg_bit(cs, KP_SPI_REG_STATUS, KP_SPI_REG_STATUS_EOT) < 0) {
+ //TODO: Figure out how to abort transaction?? This has never happened in practice though...
+ }
+
+ out:
+ return processed;
+ }
+
+ /*****************
+ * SPI Functions *
+ *****************/
+ static int
+ kp_spi_setup(struct spi_device *spidev)
+ {
+ union kp_spi_config sc;
+ struct kp_spi *kpspi = spi_master_get_devdata(spidev->master);
+ struct kp_spi_controller_state *cs;
+
+ /* setup controller state */
+ cs = spidev->controller_state;
+ if (!cs) {
+ cs = kzalloc(sizeof(*cs), GFP_KERNEL);
+ if(!cs) {
+ return -ENOMEM;
+ }
+ cs->base = kpspi->base;
+ cs->phys = kpspi->phys;
+ cs->chip_select = spidev->chip_select;
+ cs->word_len = spidev->bits_per_word;
+ cs->conf_cache = -1;
+ spidev->controller_state = cs;
+ }
+
+ /* set config register */
+ sc.bitfield.wl = spidev->bits_per_word - 1;
+ sc.bitfield.cs = spidev->chip_select;
+ sc.bitfield.spi_en = 0;
+ sc.bitfield.trm = 0;
+ sc.bitfield.ffen = 0;
+ kp_spi_write_reg(spidev->controller_state, KP_SPI_REG_CONFIG, sc.reg);
+ return 0;
+ }
+
+ static int
+ kp_spi_transfer_one_message(struct spi_master *master, struct spi_message *m)
+ {
+ struct kp_spi_controller_state *cs;
+ struct spi_device *spidev;
+ struct kp_spi *kpspi;
+ struct spi_transfer *transfer;
+ union kp_spi_config sc;
+ int status = 0;
+
+ spidev = m->spi;
+ kpspi = spi_master_get_devdata(master);
+ m->actual_length = 0;
+ m->status = 0;
+
+ cs = spidev->controller_state;
+
+ /* reject invalid messages and transfers */
+ if (list_empty(&m->transfers)) {
+ return -EINVAL;
+ }
+
+ /* validate input */
+ list_for_each_entry(transfer, &m->transfers, transfer_list) {
+ const void *tx_buf = transfer->tx_buf;
+ void *rx_buf = transfer->rx_buf;
+ unsigned len = transfer->len;
+
+ if (transfer->speed_hz > KP_SPI_CLK || (len && !(rx_buf || tx_buf))) {
+ dev_dbg(kpspi->dev, " transfer: %d Hz, %d %s%s, %d bpw\n",
+ transfer->speed_hz,
+ len,
+ tx_buf ? "tx" : "",
+ rx_buf ? "rx" : "",
+ transfer->bits_per_word);
+ dev_dbg(kpspi->dev, " transfer -EINVAL\n");
+ return -EINVAL;
+ }
+ if (transfer->speed_hz && (transfer->speed_hz < (KP_SPI_CLK >> 15))) {
+ dev_dbg(kpspi->dev, "speed_hz %d below minimum %d Hz\n",
+ transfer->speed_hz,
+ KP_SPI_CLK >> 15);
+ dev_dbg(kpspi->dev, " speed_hz -EINVAL\n");
+ return -EINVAL;
+ }
+ }
+
+ /* assert chip select to start the sequence*/
+ sc.reg = kp_spi_read_reg(cs, KP_SPI_REG_CONFIG);
+ sc.bitfield.spi_en = 1;
+ kp_spi_write_reg(cs, KP_SPI_REG_CONFIG, sc.reg);
+
+ /* work */
+ if (kp_spi_wait_for_reg_bit(cs, KP_SPI_REG_STATUS, KP_SPI_REG_STATUS_EOT) < 0) {
+ dev_info(kpspi->dev, "EOT timed out\n");
+ goto out;
+ }
+
+ /* do the transfers for this message */
+ list_for_each_entry(transfer, &m->transfers, transfer_list) {
+ if (transfer->tx_buf == NULL && transfer->rx_buf == NULL && transfer->len) {
+ status = -EINVAL;
+ break;
+ }
+
+ /* transfer */
+ if (transfer->len) {
+ unsigned int word_len = spidev->bits_per_word;
+ unsigned count;
+
+ /* set up the transfer... */
+ sc.reg = kp_spi_read_reg(cs, KP_SPI_REG_CONFIG);
+
+ /* ...direction */
+ if (transfer->tx_buf) {
+ sc.bitfield.trm = KP_SPI_REG_CONFIG_TRM_TX;
+ }
+ else if (transfer->rx_buf) {
+ sc.bitfield.trm = KP_SPI_REG_CONFIG_TRM_RX;
+ }
+
+ /* ...word length */
+ if (transfer->bits_per_word) {
+ word_len = transfer->bits_per_word;
+ }
+ cs->word_len = word_len;
+ sc.bitfield.wl = word_len-1;
+
+ /* ...chip select */
+ sc.bitfield.cs = spidev->chip_select;
+
+ /* ...and write the new settings */
+ kp_spi_write_reg(cs, KP_SPI_REG_CONFIG, sc.reg);
+
+ /* do the transfer */
+ count = kp_spi_txrx_pio(spidev, transfer);
+ m->actual_length += count;
+
+ if (count != transfer->len) {
+ status = -EIO;
+ break;
+ }
+ }
+
+ if (transfer->delay_usecs) {
+ udelay(transfer->delay_usecs);
+ }
+ }
+
+ /* de-assert chip select to end the sequence */
+ sc.reg = kp_spi_read_reg(cs, KP_SPI_REG_CONFIG);
+ sc.bitfield.spi_en = 0;
+ kp_spi_write_reg(cs, KP_SPI_REG_CONFIG, sc.reg);
+
+ out:
+ /* done work */
+ spi_finalize_current_message(master);
+ return 0;
+ }
+
+ static void
+ kp_spi_cleanup(struct spi_device *spidev)
+ {
+ struct kp_spi_controller_state *cs = spidev->controller_state;
+ if (cs) {
+ kfree(cs);
+ }
+ }
+
+
+
+ /******************
+ * Probe / Remove *
+ ******************/
+ static int
+ kp_spi_probe(struct platform_device *pldev)
+ {
+ struct kpc_core_device_platdata *drvdata;
+ struct spi_master *master;
+ struct kp_spi *kpspi;
+ struct resource *r;
+ int status = 0;
+ int i;
+
+ drvdata = pldev->dev.platform_data;
+ if (!drvdata){
+ dev_err(&pldev->dev, "kp_spi_probe: platform_data is NULL!\n");
+ return -ENODEV;
+ }
+
+ master = spi_alloc_master(&pldev->dev, sizeof(struct kp_spi));
+ if (master == NULL) {
+ dev_err(&pldev->dev, "kp_spi_probe: master allocation failed\n");
+ return -ENOMEM;
+ }
+
+ /* set up the spi functions */
+ master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+ master->bits_per_word_mask = (unsigned int)SPI_BPW_RANGE_MASK(4, 32);
+ master->setup = kp_spi_setup;
+ master->transfer_one_message = kp_spi_transfer_one_message;
+ master->cleanup = kp_spi_cleanup;
+
+ platform_set_drvdata(pldev, master);
+
+ kpspi = spi_master_get_devdata(master);
+ kpspi->master = master;
+ kpspi->dev = &pldev->dev;
+
+ master->num_chipselect = 4;
+ if (pldev->id != -1) {
+ master->bus_num = pldev->id;
+ }
+ kpspi->pin_dir = 0;
+
+ r = platform_get_resource(pldev, IORESOURCE_MEM, 0);
+ if (r == NULL) {
+ dev_err(&pldev->dev, "kp_spi_probe: Unable to get platform resources\n");
+ status = -ENODEV;
+ goto free_master;
+ }
+
+ kpspi->phys = (unsigned long)ioremap_nocache(r->start, resource_size(r));
+ kpspi->base = (u64 __iomem *)kpspi->phys;
+
+ status = spi_register_master(master);
+ if (status < 0) {
+ dev_err(&pldev->dev, "Unable to register SPI device\n");
+ goto free_master;
+ }
+
+ /* register the slave boards */
+ #define NEW_SPI_DEVICE_FROM_BOARD_INFO_TABLE(table) \
+ for (i = 0 ; i < ARRAY_SIZE(table) ; i++) { \
+ spi_new_device(master, &(table[i])); \
+ }
+
+ switch ((drvdata->card_id & 0xFFFF0000) >> 16){
+ case PCI_DEVICE_ID_DAKTRONICS_KADOKA_P2KR0:
+ NEW_SPI_DEVICE_FROM_BOARD_INFO_TABLE(p2kr0_board_info);
+ break;
+ default:
+ dev_err(&pldev->dev, "Unknown hardware, cant know what partition table to use!\n");
+ goto free_master;
+ break;
+ }
+
+ return status;
+
+ free_master:
+ spi_master_put(master);
+ return status;
+ }
+
+ static int
+ kp_spi_remove(struct platform_device *pldev)
+ {
+ struct spi_master * master = platform_get_drvdata(pldev);
+ spi_unregister_master(master);
+ return 0;
+ }
+
+
+ static struct platform_driver kp_spi_driver = {
+ .driver = {
+ .name = KP_DRIVER_NAME_SPI,
+ },
+ .probe = kp_spi_probe,
+ .remove = kp_spi_remove,
+ };
+
+ module_platform_driver(kp_spi_driver);
+ MODULE_LICENSE("GPL");
+ MODULE_ALIAS("platform:kp_spi");
projects / platform / kernel / linux-rpi.git / commitdiff