1 /* 2 * Remote processor machine-specific module for DA8XX 3 * 4 * Copyright (C) 2013 Texas Instruments, Inc. 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * version 2 as published by the Free Software Foundation. 9 */ 10 11 #include <linux/bitops.h> 12 #include <linux/clk.h> 13 #include <linux/err.h> 14 #include <linux/interrupt.h> 15 #include <linux/io.h> 16 #include <linux/irq.h> 17 #include <linux/kernel.h> 18 #include <linux/module.h> 19 #include <linux/platform_device.h> 20 #include <linux/remoteproc.h> 21 22 #include <mach/clock.h> /* for davinci_clk_reset_assert/deassert() */ 23 24 #include "remoteproc_internal.h" 25 26 static char *da8xx_fw_name; 27 module_param(da8xx_fw_name, charp, S_IRUGO); 28 MODULE_PARM_DESC(da8xx_fw_name, 29 "Name of DSP firmware file in /lib/firmware (if not specified defaults to 'rproc-dsp-fw')"); 30 31 /* 32 * OMAP-L138 Technical References: 33 * http://www.ti.com/product/omap-l138 34 */ 35 #define SYSCFG_CHIPSIG0 BIT(0) 36 #define SYSCFG_CHIPSIG1 BIT(1) 37 #define SYSCFG_CHIPSIG2 BIT(2) 38 #define SYSCFG_CHIPSIG3 BIT(3) 39 #define SYSCFG_CHIPSIG4 BIT(4) 40 41 /** 42 * struct da8xx_rproc - da8xx remote processor instance state 43 * @rproc: rproc handle 44 * @dsp_clk: placeholder for platform's DSP clk 45 * @ack_fxn: chip-specific ack function for ack'ing irq 46 * @irq_data: ack_fxn function parameter 47 * @chipsig: virt ptr to DSP interrupt registers (CHIPSIG & CHIPSIG_CLR) 48 * @bootreg: virt ptr to DSP boot address register (HOST1CFG) 49 * @irq: irq # used by this instance 50 */ 51 struct da8xx_rproc { 52 struct rproc *rproc; 53 struct clk *dsp_clk; 54 void (*ack_fxn)(struct irq_data *data); 55 struct irq_data *irq_data; 56 void __iomem *chipsig; 57 void __iomem *bootreg; 58 int irq; 59 }; 60 61 /** 62 * handle_event() - inbound virtqueue message workqueue function 63 * 64 * This function is registered as a kernel thread and is scheduled by the 65 * kernel handler. 66 */ 67 static irqreturn_t handle_event(int irq, void *p) 68 { 69 struct rproc *rproc = (struct rproc *)p; 70 71 /* Process incoming buffers on all our vrings */ 72 rproc_vq_interrupt(rproc, 0); 73 rproc_vq_interrupt(rproc, 1); 74 75 return IRQ_HANDLED; 76 } 77 78 /** 79 * da8xx_rproc_callback() - inbound virtqueue message handler 80 * 81 * This handler is invoked directly by the kernel whenever the remote 82 * core (DSP) has modified the state of a virtqueue. There is no 83 * "payload" message indicating the virtqueue index as is the case with 84 * mailbox-based implementations on OMAP4. As such, this handler "polls" 85 * each known virtqueue index for every invocation. 86 */ 87 static irqreturn_t da8xx_rproc_callback(int irq, void *p) 88 { 89 struct rproc *rproc = (struct rproc *)p; 90 struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv; 91 u32 chipsig; 92 93 chipsig = readl(drproc->chipsig); 94 if (chipsig & SYSCFG_CHIPSIG0) { 95 /* Clear interrupt level source */ 96 writel(SYSCFG_CHIPSIG0, drproc->chipsig + 4); 97 98 /* 99 * ACK intr to AINTC. 100 * 101 * It has already been ack'ed by the kernel before calling 102 * this function, but since the ARM<->DSP interrupts in the 103 * CHIPSIG register are "level" instead of "pulse" variety, 104 * we need to ack it after taking down the level else we'll 105 * be called again immediately after returning. 106 */ 107 drproc->ack_fxn(drproc->irq_data); 108 109 return IRQ_WAKE_THREAD; 110 } 111 112 return IRQ_HANDLED; 113 } 114 115 static int da8xx_rproc_start(struct rproc *rproc) 116 { 117 struct device *dev = rproc->dev.parent; 118 struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv; 119 struct clk *dsp_clk = drproc->dsp_clk; 120 121 /* hw requires the start (boot) address be on 1KB boundary */ 122 if (rproc->bootaddr & 0x3ff) { 123 dev_err(dev, "invalid boot address: must be aligned to 1KB\n"); 124 125 return -EINVAL; 126 } 127 128 writel(rproc->bootaddr, drproc->bootreg); 129 130 clk_enable(dsp_clk); 131 davinci_clk_reset_deassert(dsp_clk); 132 133 return 0; 134 } 135 136 static int da8xx_rproc_stop(struct rproc *rproc) 137 { 138 struct da8xx_rproc *drproc = rproc->priv; 139 140 clk_disable(drproc->dsp_clk); 141 142 return 0; 143 } 144 145 /* kick a virtqueue */ 146 static void da8xx_rproc_kick(struct rproc *rproc, int vqid) 147 { 148 struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv; 149 150 /* Interrupt remote proc */ 151 writel(SYSCFG_CHIPSIG2, drproc->chipsig); 152 } 153 154 static struct rproc_ops da8xx_rproc_ops = { 155 .start = da8xx_rproc_start, 156 .stop = da8xx_rproc_stop, 157 .kick = da8xx_rproc_kick, 158 }; 159 160 static int reset_assert(struct device *dev) 161 { 162 struct clk *dsp_clk; 163 164 dsp_clk = clk_get(dev, NULL); 165 if (IS_ERR(dsp_clk)) { 166 dev_err(dev, "clk_get error: %ld\n", PTR_ERR(dsp_clk)); 167 return PTR_ERR(dsp_clk); 168 } 169 170 davinci_clk_reset_assert(dsp_clk); 171 clk_put(dsp_clk); 172 173 return 0; 174 } 175 176 static int da8xx_rproc_probe(struct platform_device *pdev) 177 { 178 struct device *dev = &pdev->dev; 179 struct da8xx_rproc *drproc; 180 struct rproc *rproc; 181 struct irq_data *irq_data; 182 struct resource *bootreg_res; 183 struct resource *chipsig_res; 184 struct clk *dsp_clk; 185 void __iomem *chipsig; 186 void __iomem *bootreg; 187 int irq; 188 int ret; 189 190 irq = platform_get_irq(pdev, 0); 191 if (irq < 0) { 192 dev_err(dev, "platform_get_irq(pdev, 0) error: %d\n", irq); 193 return irq; 194 } 195 196 irq_data = irq_get_irq_data(irq); 197 if (!irq_data) { 198 dev_err(dev, "irq_get_irq_data(%d): NULL\n", irq); 199 return -EINVAL; 200 } 201 202 bootreg_res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 203 bootreg = devm_ioremap_resource(dev, bootreg_res); 204 if (IS_ERR(bootreg)) 205 return PTR_ERR(bootreg); 206 207 chipsig_res = platform_get_resource(pdev, IORESOURCE_MEM, 1); 208 chipsig = devm_ioremap_resource(dev, chipsig_res); 209 if (IS_ERR(chipsig)) 210 return PTR_ERR(chipsig); 211 212 dsp_clk = devm_clk_get(dev, NULL); 213 if (IS_ERR(dsp_clk)) { 214 dev_err(dev, "clk_get error: %ld\n", PTR_ERR(dsp_clk)); 215 216 return PTR_ERR(dsp_clk); 217 } 218 219 rproc = rproc_alloc(dev, "dsp", &da8xx_rproc_ops, da8xx_fw_name, 220 sizeof(*drproc)); 221 if (!rproc) 222 return -ENOMEM; 223 224 drproc = rproc->priv; 225 drproc->rproc = rproc; 226 rproc->has_iommu = false; 227 228 platform_set_drvdata(pdev, rproc); 229 230 /* everything the ISR needs is now setup, so hook it up */ 231 ret = devm_request_threaded_irq(dev, irq, da8xx_rproc_callback, 232 handle_event, 0, "da8xx-remoteproc", 233 rproc); 234 if (ret) { 235 dev_err(dev, "devm_request_threaded_irq error: %d\n", ret); 236 goto free_rproc; 237 } 238 239 /* 240 * rproc_add() can end up enabling the DSP's clk with the DSP 241 * *not* in reset, but da8xx_rproc_start() needs the DSP to be 242 * held in reset at the time it is called. 243 */ 244 ret = reset_assert(dev); 245 if (ret) 246 goto free_rproc; 247 248 drproc->chipsig = chipsig; 249 drproc->bootreg = bootreg; 250 drproc->ack_fxn = irq_data->chip->irq_ack; 251 drproc->irq_data = irq_data; 252 drproc->irq = irq; 253 drproc->dsp_clk = dsp_clk; 254 255 ret = rproc_add(rproc); 256 if (ret) { 257 dev_err(dev, "rproc_add failed: %d\n", ret); 258 goto free_rproc; 259 } 260 261 return 0; 262 263 free_rproc: 264 rproc_put(rproc); 265 266 return ret; 267 } 268 269 static int da8xx_rproc_remove(struct platform_device *pdev) 270 { 271 struct device *dev = &pdev->dev; 272 struct rproc *rproc = platform_get_drvdata(pdev); 273 struct da8xx_rproc *drproc = (struct da8xx_rproc *)rproc->priv; 274 275 /* 276 * It's important to place the DSP in reset before going away, 277 * since a subsequent insmod of this module may enable the DSP's 278 * clock before its program/boot-address has been loaded and 279 * before this module's probe has had a chance to reset the DSP. 280 * Without the reset, the DSP can lockup permanently when it 281 * begins executing garbage. 282 */ 283 reset_assert(dev); 284 285 /* 286 * The devm subsystem might end up releasing things before 287 * freeing the irq, thus allowing an interrupt to sneak in while 288 * the device is being removed. This should prevent that. 289 */ 290 disable_irq(drproc->irq); 291 292 rproc_del(rproc); 293 rproc_put(rproc); 294 295 return 0; 296 } 297 298 static struct platform_driver da8xx_rproc_driver = { 299 .probe = da8xx_rproc_probe, 300 .remove = da8xx_rproc_remove, 301 .driver = { 302 .name = "davinci-rproc", 303 }, 304 }; 305 306 module_platform_driver(da8xx_rproc_driver); 307 308 MODULE_LICENSE("GPL v2"); 309 MODULE_DESCRIPTION("DA8XX Remote Processor control driver"); 310