Commit | Line | Data |
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161b96c3 AS |
1 | /* |
2 | * CLPS711X SPI bus driver | |
3 | * | |
98984796 | 4 | * Copyright (C) 2012-2014 Alexander Shiyan <shc_work@mail.ru> |
161b96c3 AS |
5 | * |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; either version 2 of the License, or | |
9 | * (at your option) any later version. | |
10 | */ | |
11 | ||
12 | #include <linux/io.h> | |
13 | #include <linux/clk.h> | |
14 | #include <linux/init.h> | |
15 | #include <linux/gpio.h> | |
16 | #include <linux/delay.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/interrupt.h> | |
19 | #include <linux/platform_device.h> | |
20 | #include <linux/spi/spi.h> | |
21 | #include <linux/platform_data/spi-clps711x.h> | |
22 | ||
23 | #include <mach/hardware.h> | |
24 | ||
25 | #define DRIVER_NAME "spi-clps711x" | |
26 | ||
27 | struct spi_clps711x_data { | |
161b96c3 AS |
28 | struct clk *spi_clk; |
29 | u32 max_speed_hz; | |
30 | ||
31 | u8 *tx_buf; | |
32 | u8 *rx_buf; | |
8dda9d9a | 33 | unsigned int bpw; |
161b96c3 | 34 | int len; |
161b96c3 AS |
35 | }; |
36 | ||
37 | static int spi_clps711x_setup(struct spi_device *spi) | |
38 | { | |
161b96c3 | 39 | /* We are expect that SPI-device is not selected */ |
3e9ea4b4 | 40 | gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH)); |
161b96c3 AS |
41 | |
42 | return 0; | |
43 | } | |
44 | ||
8dda9d9a AS |
45 | static void spi_clps711x_setup_xfer(struct spi_device *spi, |
46 | struct spi_transfer *xfer) | |
161b96c3 AS |
47 | { |
48 | u32 speed = xfer->speed_hz ? : spi->max_speed_hz; | |
161b96c3 AS |
49 | struct spi_clps711x_data *hw = spi_master_get_devdata(spi->master); |
50 | ||
161b96c3 AS |
51 | /* Setup SPI frequency divider */ |
52 | if (!speed || (speed >= hw->max_speed_hz)) | |
53 | clps_writel((clps_readl(SYSCON1) & ~SYSCON1_ADCKSEL_MASK) | | |
54 | SYSCON1_ADCKSEL(3), SYSCON1); | |
55 | else if (speed >= (hw->max_speed_hz / 2)) | |
56 | clps_writel((clps_readl(SYSCON1) & ~SYSCON1_ADCKSEL_MASK) | | |
57 | SYSCON1_ADCKSEL(2), SYSCON1); | |
58 | else if (speed >= (hw->max_speed_hz / 8)) | |
59 | clps_writel((clps_readl(SYSCON1) & ~SYSCON1_ADCKSEL_MASK) | | |
60 | SYSCON1_ADCKSEL(1), SYSCON1); | |
61 | else | |
62 | clps_writel((clps_readl(SYSCON1) & ~SYSCON1_ADCKSEL_MASK) | | |
63 | SYSCON1_ADCKSEL(0), SYSCON1); | |
161b96c3 AS |
64 | } |
65 | ||
bf5c2e27 AL |
66 | static int spi_clps711x_prepare_message(struct spi_master *master, |
67 | struct spi_message *msg) | |
161b96c3 | 68 | { |
8dda9d9a | 69 | struct spi_device *spi = msg->spi; |
161b96c3 | 70 | |
bf5c2e27 AL |
71 | /* Setup edge for transfer */ |
72 | if (spi->mode & SPI_CPHA) | |
73 | clps_writew(clps_readw(SYSCON3) | SYSCON3_ADCCKNSEN, SYSCON3); | |
74 | else | |
75 | clps_writew(clps_readw(SYSCON3) & ~SYSCON3_ADCCKNSEN, SYSCON3); | |
161b96c3 | 76 | |
bf5c2e27 AL |
77 | return 0; |
78 | } | |
161b96c3 | 79 | |
bf5c2e27 AL |
80 | static int spi_clps711x_transfer_one(struct spi_master *master, |
81 | struct spi_device *spi, | |
82 | struct spi_transfer *xfer) | |
83 | { | |
84 | struct spi_clps711x_data *hw = spi_master_get_devdata(master); | |
85 | u8 data; | |
161b96c3 | 86 | |
bf5c2e27 | 87 | spi_clps711x_setup_xfer(spi, xfer); |
161b96c3 | 88 | |
bf5c2e27 AL |
89 | hw->len = xfer->len; |
90 | hw->bpw = xfer->bits_per_word ? : spi->bits_per_word; | |
91 | hw->tx_buf = (u8 *)xfer->tx_buf; | |
92 | hw->rx_buf = (u8 *)xfer->rx_buf; | |
161b96c3 | 93 | |
bf5c2e27 AL |
94 | /* Initiate transfer */ |
95 | data = hw->tx_buf ? *hw->tx_buf++ : 0; | |
96 | clps_writel(data | SYNCIO_FRMLEN(hw->bpw) | SYNCIO_TXFRMEN, SYNCIO); | |
97 | return 1; | |
161b96c3 AS |
98 | } |
99 | ||
100 | static irqreturn_t spi_clps711x_isr(int irq, void *dev_id) | |
101 | { | |
bf5c2e27 AL |
102 | struct spi_master *master = dev_id; |
103 | struct spi_clps711x_data *hw = spi_master_get_devdata(master); | |
c7a26f12 | 104 | u8 data; |
161b96c3 AS |
105 | |
106 | /* Handle RX */ | |
107 | data = clps_readb(SYNCIO); | |
108 | if (hw->rx_buf) | |
c7a26f12 | 109 | *hw->rx_buf++ = data; |
161b96c3 AS |
110 | |
111 | /* Handle TX */ | |
c7a26f12 AS |
112 | if (--hw->len > 0) { |
113 | data = hw->tx_buf ? *hw->tx_buf++ : 0; | |
8dda9d9a AS |
114 | clps_writel(data | SYNCIO_FRMLEN(hw->bpw) | SYNCIO_TXFRMEN, |
115 | SYNCIO); | |
161b96c3 | 116 | } else |
bf5c2e27 | 117 | spi_finalize_current_transfer(master); |
161b96c3 AS |
118 | |
119 | return IRQ_HANDLED; | |
120 | } | |
121 | ||
fd4a319b | 122 | static int spi_clps711x_probe(struct platform_device *pdev) |
161b96c3 AS |
123 | { |
124 | int i, ret; | |
125 | struct spi_master *master; | |
126 | struct spi_clps711x_data *hw; | |
127 | struct spi_clps711x_pdata *pdata = dev_get_platdata(&pdev->dev); | |
128 | ||
129 | if (!pdata) { | |
130 | dev_err(&pdev->dev, "No platform data supplied\n"); | |
131 | return -EINVAL; | |
132 | } | |
133 | ||
134 | if (pdata->num_chipselect < 1) { | |
135 | dev_err(&pdev->dev, "At least one CS must be defined\n"); | |
136 | return -EINVAL; | |
137 | } | |
138 | ||
3e9ea4b4 AS |
139 | master = spi_alloc_master(&pdev->dev, sizeof(*hw)); |
140 | if (!master) | |
161b96c3 | 141 | return -ENOMEM; |
3e9ea4b4 AS |
142 | |
143 | master->cs_gpios = devm_kzalloc(&pdev->dev, sizeof(int) * | |
144 | pdata->num_chipselect, GFP_KERNEL); | |
145 | if (!master->cs_gpios) { | |
146 | ret = -ENOMEM; | |
147 | goto err_out; | |
161b96c3 AS |
148 | } |
149 | ||
150 | master->bus_num = pdev->id; | |
151 | master->mode_bits = SPI_CPHA | SPI_CS_HIGH; | |
8dda9d9a | 152 | master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 8); |
161b96c3 AS |
153 | master->num_chipselect = pdata->num_chipselect; |
154 | master->setup = spi_clps711x_setup; | |
bf5c2e27 AL |
155 | master->prepare_message = spi_clps711x_prepare_message; |
156 | master->transfer_one = spi_clps711x_transfer_one; | |
161b96c3 AS |
157 | |
158 | hw = spi_master_get_devdata(master); | |
159 | ||
160 | for (i = 0; i < master->num_chipselect; i++) { | |
3e9ea4b4 | 161 | master->cs_gpios[i] = pdata->chipselect[i]; |
fcba212d AL |
162 | ret = devm_gpio_request(&pdev->dev, master->cs_gpios[i], |
163 | DRIVER_NAME); | |
164 | if (ret) { | |
161b96c3 | 165 | dev_err(&pdev->dev, "Can't get CS GPIO %i\n", i); |
161b96c3 AS |
166 | goto err_out; |
167 | } | |
168 | } | |
169 | ||
170 | hw->spi_clk = devm_clk_get(&pdev->dev, "spi"); | |
171 | if (IS_ERR(hw->spi_clk)) { | |
172 | dev_err(&pdev->dev, "Can't get clocks\n"); | |
173 | ret = PTR_ERR(hw->spi_clk); | |
174 | goto err_out; | |
175 | } | |
176 | hw->max_speed_hz = clk_get_rate(hw->spi_clk); | |
177 | ||
161b96c3 AS |
178 | platform_set_drvdata(pdev, master); |
179 | ||
180 | /* Disable extended mode due hardware problems */ | |
181 | clps_writew(clps_readw(SYSCON3) & ~SYSCON3_ADCCON, SYSCON3); | |
182 | ||
183 | /* Clear possible pending interrupt */ | |
184 | clps_readl(SYNCIO); | |
185 | ||
186 | ret = devm_request_irq(&pdev->dev, IRQ_SSEOTI, spi_clps711x_isr, 0, | |
bf5c2e27 | 187 | dev_name(&pdev->dev), master); |
161b96c3 AS |
188 | if (ret) { |
189 | dev_err(&pdev->dev, "Can't request IRQ\n"); | |
c7083790 | 190 | goto err_out; |
161b96c3 AS |
191 | } |
192 | ||
c493fc4b | 193 | ret = devm_spi_register_master(&pdev->dev, master); |
161b96c3 AS |
194 | if (!ret) { |
195 | dev_info(&pdev->dev, | |
196 | "SPI bus driver initialized. Master clock %u Hz\n", | |
197 | hw->max_speed_hz); | |
198 | return 0; | |
199 | } | |
200 | ||
201 | dev_err(&pdev->dev, "Failed to register master\n"); | |
161b96c3 | 202 | |
161b96c3 | 203 | err_out: |
161b96c3 | 204 | spi_master_put(master); |
161b96c3 AS |
205 | |
206 | return ret; | |
207 | } | |
208 | ||
161b96c3 AS |
209 | static struct platform_driver clps711x_spi_driver = { |
210 | .driver = { | |
211 | .name = DRIVER_NAME, | |
212 | .owner = THIS_MODULE, | |
213 | }, | |
214 | .probe = spi_clps711x_probe, | |
161b96c3 AS |
215 | }; |
216 | module_platform_driver(clps711x_spi_driver); | |
217 | ||
218 | MODULE_LICENSE("GPL"); | |
219 | MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>"); | |
220 | MODULE_DESCRIPTION("CLPS711X SPI bus driver"); | |
350a9b33 | 221 | MODULE_ALIAS("platform:" DRIVER_NAME); |