Thomas Gleixner | d2912cb | 2019-06-04 10:11:33 +0200 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 2 | /* |
| 3 | * Altera SPI driver |
| 4 | * |
| 5 | * Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw> |
| 6 | * |
| 7 | * Based on spi_s3c24xx.c, which is: |
| 8 | * Copyright (c) 2006 Ben Dooks |
| 9 | * Copyright (c) 2006 Simtec Electronics |
| 10 | * Ben Dooks <ben@simtec.co.uk> |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 11 | */ |
| 12 | |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 13 | #include <linux/interrupt.h> |
| 14 | #include <linux/errno.h> |
Paul Gortmaker | d7614de | 2011-07-03 15:44:29 -0400 | [diff] [blame] | 15 | #include <linux/module.h> |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 16 | #include <linux/platform_device.h> |
| 17 | #include <linux/spi/spi.h> |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 18 | #include <linux/io.h> |
| 19 | #include <linux/of.h> |
| 20 | |
| 21 | #define DRV_NAME "spi_altera" |
| 22 | |
| 23 | #define ALTERA_SPI_RXDATA 0 |
| 24 | #define ALTERA_SPI_TXDATA 4 |
| 25 | #define ALTERA_SPI_STATUS 8 |
| 26 | #define ALTERA_SPI_CONTROL 12 |
| 27 | #define ALTERA_SPI_SLAVE_SEL 20 |
| 28 | |
| 29 | #define ALTERA_SPI_STATUS_ROE_MSK 0x8 |
| 30 | #define ALTERA_SPI_STATUS_TOE_MSK 0x10 |
| 31 | #define ALTERA_SPI_STATUS_TMT_MSK 0x20 |
| 32 | #define ALTERA_SPI_STATUS_TRDY_MSK 0x40 |
| 33 | #define ALTERA_SPI_STATUS_RRDY_MSK 0x80 |
| 34 | #define ALTERA_SPI_STATUS_E_MSK 0x100 |
| 35 | |
| 36 | #define ALTERA_SPI_CONTROL_IROE_MSK 0x8 |
| 37 | #define ALTERA_SPI_CONTROL_ITOE_MSK 0x10 |
| 38 | #define ALTERA_SPI_CONTROL_ITRDY_MSK 0x40 |
| 39 | #define ALTERA_SPI_CONTROL_IRRDY_MSK 0x80 |
| 40 | #define ALTERA_SPI_CONTROL_IE_MSK 0x100 |
| 41 | #define ALTERA_SPI_CONTROL_SSO_MSK 0x400 |
| 42 | |
| 43 | struct altera_spi { |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 44 | void __iomem *base; |
| 45 | int irq; |
| 46 | int len; |
| 47 | int count; |
| 48 | int bytes_per_word; |
| 49 | unsigned long imr; |
| 50 | |
| 51 | /* data buffers */ |
| 52 | const unsigned char *tx; |
| 53 | unsigned char *rx; |
| 54 | }; |
| 55 | |
| 56 | static inline struct altera_spi *altera_spi_to_hw(struct spi_device *sdev) |
| 57 | { |
| 58 | return spi_master_get_devdata(sdev->master); |
| 59 | } |
| 60 | |
Lars-Peter Clausen | e19b63c | 2017-08-16 11:33:11 +0200 | [diff] [blame] | 61 | static void altera_spi_set_cs(struct spi_device *spi, bool is_high) |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 62 | { |
| 63 | struct altera_spi *hw = altera_spi_to_hw(spi); |
| 64 | |
Lars-Peter Clausen | e19b63c | 2017-08-16 11:33:11 +0200 | [diff] [blame] | 65 | if (is_high) { |
| 66 | hw->imr &= ~ALTERA_SPI_CONTROL_SSO_MSK; |
| 67 | writel(hw->imr, hw->base + ALTERA_SPI_CONTROL); |
| 68 | writel(0, hw->base + ALTERA_SPI_SLAVE_SEL); |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 69 | } else { |
Lars-Peter Clausen | e19b63c | 2017-08-16 11:33:11 +0200 | [diff] [blame] | 70 | writel(BIT(spi->chip_select), hw->base + ALTERA_SPI_SLAVE_SEL); |
| 71 | hw->imr |= ALTERA_SPI_CONTROL_SSO_MSK; |
| 72 | writel(hw->imr, hw->base + ALTERA_SPI_CONTROL); |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 73 | } |
| 74 | } |
| 75 | |
Lars-Peter Clausen | b64836a | 2017-08-16 11:33:12 +0200 | [diff] [blame] | 76 | static void altera_spi_tx_word(struct altera_spi *hw) |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 77 | { |
Lars-Peter Clausen | b64836a | 2017-08-16 11:33:12 +0200 | [diff] [blame] | 78 | unsigned int txd = 0; |
| 79 | |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 80 | if (hw->tx) { |
| 81 | switch (hw->bytes_per_word) { |
| 82 | case 1: |
Lars-Peter Clausen | b64836a | 2017-08-16 11:33:12 +0200 | [diff] [blame] | 83 | txd = hw->tx[hw->count]; |
| 84 | break; |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 85 | case 2: |
Lars-Peter Clausen | b64836a | 2017-08-16 11:33:12 +0200 | [diff] [blame] | 86 | txd = (hw->tx[hw->count * 2] |
| 87 | | (hw->tx[hw->count * 2 + 1] << 8)); |
| 88 | break; |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 89 | } |
| 90 | } |
Lars-Peter Clausen | b64836a | 2017-08-16 11:33:12 +0200 | [diff] [blame] | 91 | |
| 92 | writel(txd, hw->base + ALTERA_SPI_TXDATA); |
| 93 | } |
| 94 | |
| 95 | static void altera_spi_rx_word(struct altera_spi *hw) |
| 96 | { |
| 97 | unsigned int rxd; |
| 98 | |
| 99 | rxd = readl(hw->base + ALTERA_SPI_RXDATA); |
| 100 | if (hw->rx) { |
| 101 | switch (hw->bytes_per_word) { |
| 102 | case 1: |
| 103 | hw->rx[hw->count] = rxd; |
| 104 | break; |
| 105 | case 2: |
| 106 | hw->rx[hw->count * 2] = rxd; |
| 107 | hw->rx[hw->count * 2 + 1] = rxd >> 8; |
| 108 | break; |
| 109 | } |
| 110 | } |
| 111 | |
| 112 | hw->count++; |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 113 | } |
| 114 | |
Lars-Peter Clausen | e19b63c | 2017-08-16 11:33:11 +0200 | [diff] [blame] | 115 | static int altera_spi_txrx(struct spi_master *master, |
| 116 | struct spi_device *spi, struct spi_transfer *t) |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 117 | { |
Lars-Peter Clausen | e19b63c | 2017-08-16 11:33:11 +0200 | [diff] [blame] | 118 | struct altera_spi *hw = spi_master_get_devdata(master); |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 119 | |
| 120 | hw->tx = t->tx_buf; |
| 121 | hw->rx = t->rx_buf; |
| 122 | hw->count = 0; |
Axel Lin | f073d37 | 2013-08-29 23:41:20 +0800 | [diff] [blame] | 123 | hw->bytes_per_word = DIV_ROUND_UP(t->bits_per_word, 8); |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 124 | hw->len = t->len / hw->bytes_per_word; |
| 125 | |
| 126 | if (hw->irq >= 0) { |
| 127 | /* enable receive interrupt */ |
| 128 | hw->imr |= ALTERA_SPI_CONTROL_IRRDY_MSK; |
| 129 | writel(hw->imr, hw->base + ALTERA_SPI_CONTROL); |
| 130 | |
| 131 | /* send the first byte */ |
Lars-Peter Clausen | b64836a | 2017-08-16 11:33:12 +0200 | [diff] [blame] | 132 | altera_spi_tx_word(hw); |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 133 | } else { |
Axel Lin | 72be0ee | 2013-08-15 14:18:46 +0800 | [diff] [blame] | 134 | while (hw->count < hw->len) { |
Lars-Peter Clausen | b64836a | 2017-08-16 11:33:12 +0200 | [diff] [blame] | 135 | altera_spi_tx_word(hw); |
Axel Lin | 72be0ee | 2013-08-15 14:18:46 +0800 | [diff] [blame] | 136 | |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 137 | while (!(readl(hw->base + ALTERA_SPI_STATUS) & |
| 138 | ALTERA_SPI_STATUS_RRDY_MSK)) |
| 139 | cpu_relax(); |
| 140 | |
Lars-Peter Clausen | b64836a | 2017-08-16 11:33:12 +0200 | [diff] [blame] | 141 | altera_spi_rx_word(hw); |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 142 | } |
Lars-Peter Clausen | e19b63c | 2017-08-16 11:33:11 +0200 | [diff] [blame] | 143 | spi_finalize_current_transfer(master); |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 144 | } |
| 145 | |
Lars-Peter Clausen | e19b63c | 2017-08-16 11:33:11 +0200 | [diff] [blame] | 146 | return t->len; |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 147 | } |
| 148 | |
| 149 | static irqreturn_t altera_spi_irq(int irq, void *dev) |
| 150 | { |
Lars-Peter Clausen | e19b63c | 2017-08-16 11:33:11 +0200 | [diff] [blame] | 151 | struct spi_master *master = dev; |
| 152 | struct altera_spi *hw = spi_master_get_devdata(master); |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 153 | |
Lars-Peter Clausen | b64836a | 2017-08-16 11:33:12 +0200 | [diff] [blame] | 154 | altera_spi_rx_word(hw); |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 155 | |
Lars-Peter Clausen | e19b63c | 2017-08-16 11:33:11 +0200 | [diff] [blame] | 156 | if (hw->count < hw->len) { |
Lars-Peter Clausen | b64836a | 2017-08-16 11:33:12 +0200 | [diff] [blame] | 157 | altera_spi_tx_word(hw); |
Lars-Peter Clausen | e19b63c | 2017-08-16 11:33:11 +0200 | [diff] [blame] | 158 | } else { |
| 159 | /* disable receive interrupt */ |
| 160 | hw->imr &= ~ALTERA_SPI_CONTROL_IRRDY_MSK; |
| 161 | writel(hw->imr, hw->base + ALTERA_SPI_CONTROL); |
| 162 | |
| 163 | spi_finalize_current_transfer(master); |
| 164 | } |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 165 | |
| 166 | return IRQ_HANDLED; |
| 167 | } |
| 168 | |
Grant Likely | fd4a319 | 2012-12-07 16:57:14 +0000 | [diff] [blame] | 169 | static int altera_spi_probe(struct platform_device *pdev) |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 170 | { |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 171 | struct altera_spi *hw; |
| 172 | struct spi_master *master; |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 173 | int err = -ENODEV; |
| 174 | |
| 175 | master = spi_alloc_master(&pdev->dev, sizeof(struct altera_spi)); |
| 176 | if (!master) |
| 177 | return err; |
| 178 | |
| 179 | /* setup the master state. */ |
| 180 | master->bus_num = pdev->id; |
| 181 | master->num_chipselect = 16; |
| 182 | master->mode_bits = SPI_CS_HIGH; |
Axel Lin | 72bb79d | 2014-03-05 13:37:00 +0800 | [diff] [blame] | 183 | master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 16); |
Axel Lin | bf2f2f7 | 2014-03-21 11:21:58 +0800 | [diff] [blame] | 184 | master->dev.of_node = pdev->dev.of_node; |
Lars-Peter Clausen | e19b63c | 2017-08-16 11:33:11 +0200 | [diff] [blame] | 185 | master->transfer_one = altera_spi_txrx; |
| 186 | master->set_cs = altera_spi_set_cs; |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 187 | |
| 188 | hw = spi_master_get_devdata(master); |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 189 | |
| 190 | /* find and map our resources */ |
YueHaibing | 5277ab6 | 2019-09-04 21:58:43 +0800 | [diff] [blame] | 191 | hw->base = devm_platform_ioremap_resource(pdev, 0); |
Julia Lawall | b3136f8 | 2013-08-24 19:13:15 +0200 | [diff] [blame] | 192 | if (IS_ERR(hw->base)) { |
| 193 | err = PTR_ERR(hw->base); |
| 194 | goto exit; |
| 195 | } |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 196 | /* program defaults into the registers */ |
| 197 | hw->imr = 0; /* disable spi interrupts */ |
| 198 | writel(hw->imr, hw->base + ALTERA_SPI_CONTROL); |
| 199 | writel(0, hw->base + ALTERA_SPI_STATUS); /* clear status reg */ |
| 200 | if (readl(hw->base + ALTERA_SPI_STATUS) & ALTERA_SPI_STATUS_RRDY_MSK) |
| 201 | readl(hw->base + ALTERA_SPI_RXDATA); /* flush rxdata */ |
| 202 | /* irq is optional */ |
| 203 | hw->irq = platform_get_irq(pdev, 0); |
| 204 | if (hw->irq >= 0) { |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 205 | err = devm_request_irq(&pdev->dev, hw->irq, altera_spi_irq, 0, |
Lars-Peter Clausen | e19b63c | 2017-08-16 11:33:11 +0200 | [diff] [blame] | 206 | pdev->name, master); |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 207 | if (err) |
| 208 | goto exit; |
| 209 | } |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 210 | |
Lars-Peter Clausen | e19b63c | 2017-08-16 11:33:11 +0200 | [diff] [blame] | 211 | err = devm_spi_register_master(&pdev->dev, master); |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 212 | if (err) |
| 213 | goto exit; |
| 214 | dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq); |
| 215 | |
| 216 | return 0; |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 217 | exit: |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 218 | spi_master_put(master); |
| 219 | return err; |
| 220 | } |
| 221 | |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 222 | #ifdef CONFIG_OF |
| 223 | static const struct of_device_id altera_spi_match[] = { |
| 224 | { .compatible = "ALTR,spi-1.0", }, |
Dinh Nguyen | 13960b4 | 2013-08-14 15:25:19 -0500 | [diff] [blame] | 225 | { .compatible = "altr,spi-1.0", }, |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 226 | {}, |
| 227 | }; |
| 228 | MODULE_DEVICE_TABLE(of, altera_spi_match); |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 229 | #endif /* CONFIG_OF */ |
| 230 | |
| 231 | static struct platform_driver altera_spi_driver = { |
| 232 | .probe = altera_spi_probe, |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 233 | .driver = { |
| 234 | .name = DRV_NAME, |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 235 | .pm = NULL, |
Tobias Klauser | 89f98dc | 2012-08-15 09:30:28 +0200 | [diff] [blame] | 236 | .of_match_table = of_match_ptr(altera_spi_match), |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 237 | }, |
| 238 | }; |
Grant Likely | 940ab88 | 2011-10-05 11:29:49 -0600 | [diff] [blame] | 239 | module_platform_driver(altera_spi_driver); |
Thomas Chou | 0b78253 | 2011-02-14 10:10:43 +0800 | [diff] [blame] | 240 | |
| 241 | MODULE_DESCRIPTION("Altera SPI driver"); |
| 242 | MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>"); |
| 243 | MODULE_LICENSE("GPL"); |
| 244 | MODULE_ALIAS("platform:" DRV_NAME); |