1/*
  2 * Adding PCI-E MSI support for PPC4XX SoCs.
  3 *
  4 * Copyright (c) 2010, Applied Micro Circuits Corporation
  5 * Authors:	Tirumala R Marri <tmarri@apm.com>
  6 *		Feng Kan <fkan@apm.com>
  7 *
  8 * This program is free software; you can redistribute it and/or
  9 * modify it under the terms of the GNU General Public License as
 10 * published by the Free Software Foundation; either version 2 of
 11 * the License, or (at your option) any later version.
 12 *
 13 * This program is distributed in the hope that it will be useful,
 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 16 * GNU General Public License for more details.
 17 *
 18 * You should have received a copy of the GNU General Public License
 19 * along with this program; if not, write to the Free Software
 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 21 * MA 02111-1307 USA
 22 */
 23
 24#include <linux/irq.h>
 25#include <linux/bootmem.h>
 26#include <linux/pci.h>
 27#include <linux/msi.h>
 28#include <linux/of_platform.h>
 29#include <linux/interrupt.h>
 30#include <asm/prom.h>
 31#include <asm/hw_irq.h>
 32#include <asm/ppc-pci.h>
 33#include <boot/dcr.h>
 34#include <asm/dcr-regs.h>
 35#include <asm/msi_bitmap.h>
 36
 37#define PEIH_TERMADH	0x00
 38#define PEIH_TERMADL	0x08
 39#define PEIH_MSIED	0x10
 40#define PEIH_MSIMK	0x18
 41#define PEIH_MSIASS	0x20
 42#define PEIH_FLUSH0	0x30
 43#define PEIH_FLUSH1	0x38
 44#define PEIH_CNTRST	0x48
 45#define NR_MSI_IRQS	4
 46
 47struct ppc4xx_msi {
 48	u32 msi_addr_lo;
 49	u32 msi_addr_hi;
 50	void __iomem *msi_regs;
 51	int msi_virqs[NR_MSI_IRQS];
 52	struct msi_bitmap bitmap;
 53	struct device_node *msi_dev;
 54};
 55
 56static struct ppc4xx_msi ppc4xx_msi;
 57
 58static int ppc4xx_msi_init_allocator(struct platform_device *dev,
 59		struct ppc4xx_msi *msi_data)
 60{
 61	int err;
 62
 63	err = msi_bitmap_alloc(&msi_data->bitmap, NR_MSI_IRQS,
 64			      dev->dev.of_node);
 65	if (err)
 66		return err;
 67
 68	err = msi_bitmap_reserve_dt_hwirqs(&msi_data->bitmap);
 69	if (err < 0) {
 70		msi_bitmap_free(&msi_data->bitmap);
 71		return err;
 72	}
 73
 74	return 0;
 75}
 76
 77static int ppc4xx_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 78{
 79	int int_no = -ENOMEM;
 80	unsigned int virq;
 81	struct msi_msg msg;
 82	struct msi_desc *entry;
 83	struct ppc4xx_msi *msi_data = &ppc4xx_msi;
 84
 85	list_for_each_entry(entry, &dev->msi_list, list) {
 86		int_no = msi_bitmap_alloc_hwirqs(&msi_data->bitmap, 1);
 87		if (int_no >= 0)
 88			break;
 89		if (int_no < 0) {
 90			pr_debug("%s: fail allocating msi interrupt\n",
 91					__func__);
 92		}
 93		virq = irq_of_parse_and_map(msi_data->msi_dev, int_no);
 94		if (virq == NO_IRQ) {
 95			dev_err(&dev->dev, "%s: fail mapping irq\n", __func__);
 96			msi_bitmap_free_hwirqs(&msi_data->bitmap, int_no, 1);
 97			return -ENOSPC;
 98		}
 99		dev_dbg(&dev->dev, "%s: virq = %d\n", __func__, virq);
100
101		/* Setup msi address space */
102		msg.address_hi = msi_data->msi_addr_hi;
103		msg.address_lo = msi_data->msi_addr_lo;
104
105		irq_set_msi_desc(virq, entry);
106		msg.data = int_no;
107		write_msi_msg(virq, &msg);
108	}
109	return 0;
110}
111
112void ppc4xx_teardown_msi_irqs(struct pci_dev *dev)
113{
114	struct msi_desc *entry;
115	struct ppc4xx_msi *msi_data = &ppc4xx_msi;
116
117	dev_dbg(&dev->dev, "PCIE-MSI: tearing down msi irqs\n");
118
119	list_for_each_entry(entry, &dev->msi_list, list) {
120		if (entry->irq == NO_IRQ)
121			continue;
122		irq_set_msi_desc(entry->irq, NULL);
123		msi_bitmap_free_hwirqs(&msi_data->bitmap,
124				virq_to_hw(entry->irq), 1);
125		irq_dispose_mapping(entry->irq);
126	}
127}
128
129static int ppc4xx_msi_check_device(struct pci_dev *pdev, int nvec, int type)
130{
131	dev_dbg(&pdev->dev, "PCIE-MSI:%s called. vec %x type %d\n",
132		__func__, nvec, type);
133	if (type == PCI_CAP_ID_MSIX)
134		pr_debug("ppc4xx msi: MSI-X untested, trying anyway.\n");
135
136	return 0;
137}
138
139static int ppc4xx_setup_pcieh_hw(struct platform_device *dev,
140				 struct resource res, struct ppc4xx_msi *msi)
141{
142	const u32 *msi_data;
143	const u32 *msi_mask;
144	const u32 *sdr_addr;
145	dma_addr_t msi_phys;
146	void *msi_virt;
147
148	sdr_addr = of_get_property(dev->dev.of_node, "sdr-base", NULL);
149	if (!sdr_addr)
150		return -1;
151
152	SDR0_WRITE(sdr_addr, (u64)res.start >> 32);	 /*HIGH addr */
153	SDR0_WRITE(sdr_addr + 1, res.start & 0xFFFFFFFF); /* Low addr */
154
155
156	msi->msi_dev = of_find_node_by_name(NULL, "ppc4xx-msi");
157	if (msi->msi_dev)
158		return -ENODEV;
159
160	msi->msi_regs = of_iomap(msi->msi_dev, 0);
161	if (!msi->msi_regs) {
162		dev_err(&dev->dev, "of_iomap problem failed\n");
163		return -ENOMEM;
164	}
165	dev_dbg(&dev->dev, "PCIE-MSI: msi register mapped 0x%x 0x%x\n",
166		(u32) (msi->msi_regs + PEIH_TERMADH), (u32) (msi->msi_regs));
167
168	msi_virt = dma_alloc_coherent(&dev->dev, 64, &msi_phys, GFP_KERNEL);
169	msi->msi_addr_hi = 0x0;
170	msi->msi_addr_lo = (u32) msi_phys;
171	dev_dbg(&dev->dev, "PCIE-MSI: msi address 0x%x\n", msi->msi_addr_lo);
172
173	/* Progam the Interrupt handler Termination addr registers */
174	out_be32(msi->msi_regs + PEIH_TERMADH, msi->msi_addr_hi);
175	out_be32(msi->msi_regs + PEIH_TERMADL, msi->msi_addr_lo);
176
177	msi_data = of_get_property(dev->dev.of_node, "msi-data", NULL);
178	if (!msi_data)
179		return -1;
180	msi_mask = of_get_property(dev->dev.of_node, "msi-mask", NULL);
181	if (!msi_mask)
182		return -1;
183	/* Program MSI Expected data and Mask bits */
184	out_be32(msi->msi_regs + PEIH_MSIED, *msi_data);
185	out_be32(msi->msi_regs + PEIH_MSIMK, *msi_mask);
186
187	return 0;
188}
189
190static int ppc4xx_of_msi_remove(struct platform_device *dev)
191{
192	struct ppc4xx_msi *msi = dev->dev.platform_data;
193	int i;
194	int virq;
195
196	for (i = 0; i < NR_MSI_IRQS; i++) {
197		virq = msi->msi_virqs[i];
198		if (virq != NO_IRQ)
199			irq_dispose_mapping(virq);
200	}
201
202	if (msi->bitmap.bitmap)
203		msi_bitmap_free(&msi->bitmap);
204	iounmap(msi->msi_regs);
205	of_node_put(msi->msi_dev);
206	kfree(msi);
207
208	return 0;
209}
210
211static int __devinit ppc4xx_msi_probe(struct platform_device *dev)
212{
213	struct ppc4xx_msi *msi;
214	struct resource res;
215	int err = 0;
216
217	msi = &ppc4xx_msi;/*keep the msi data for further use*/
218
219	dev_dbg(&dev->dev, "PCIE-MSI: Setting up MSI support...\n");
220
221	msi = kzalloc(sizeof(struct ppc4xx_msi), GFP_KERNEL);
222	if (!msi) {
223		dev_err(&dev->dev, "No memory for MSI structure\n");
224		return -ENOMEM;
225	}
226	dev->dev.platform_data = msi;
227
228	/* Get MSI ranges */
229	err = of_address_to_resource(dev->dev.of_node, 0, &res);
230	if (err) {
231		dev_err(&dev->dev, "%s resource error!\n",
232			dev->dev.of_node->full_name);
233		goto error_out;
234	}
235
236	if (ppc4xx_setup_pcieh_hw(dev, res, msi))
237		goto error_out;
238
239	err = ppc4xx_msi_init_allocator(dev, msi);
240	if (err) {
241		dev_err(&dev->dev, "Error allocating MSI bitmap\n");
242		goto error_out;
243	}
244
245	ppc_md.setup_msi_irqs = ppc4xx_setup_msi_irqs;
246	ppc_md.teardown_msi_irqs = ppc4xx_teardown_msi_irqs;
247	ppc_md.msi_check_device = ppc4xx_msi_check_device;
248	return err;
249
250error_out:
251	ppc4xx_of_msi_remove(dev);
252	return err;
253}
254static const struct of_device_id ppc4xx_msi_ids[] = {
255	{
256		.compatible = "amcc,ppc4xx-msi",
257	},
258	{}
259};
260static struct platform_driver ppc4xx_msi_driver = {
261	.probe = ppc4xx_msi_probe,
262	.remove = ppc4xx_of_msi_remove,
263	.driver = {
264		   .name = "ppc4xx-msi",
265		   .owner = THIS_MODULE,
266		   .of_match_table = ppc4xx_msi_ids,
267		   },
268
269};
270
271static __init int ppc4xx_msi_init(void)
272{
273	return platform_driver_register(&ppc4xx_msi_driver);
274}
275
276subsys_initcall(ppc4xx_msi_init);