1 // SPDX-License-Identifier: GPL-2.0-only
8  * Christophe Ricard <christophe-h.ricard@st.com>
10  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
42  * TCG SPI flow control is documented in section 6.4 of the spec[1]. In short,
46  * [1] https://trustedcomputinggroup.org/resource/pc-client-platform-tpm-profile-ptp-specification/
54 	if ((phy->iobuf[3] & 0x01) == 0) {  in tpm_tis_spi_flow_control()
57 			spi_xfer->len = 1;  in tpm_tis_spi_flow_control()
60 			ret = spi_sync_locked(phy->spi_device, &m);  in tpm_tis_spi_flow_control()
63 			if (phy->iobuf[0] & 0x01)  in tpm_tis_spi_flow_control()
68 			return -ETIMEDOUT;  in tpm_tis_spi_flow_control()
75  * Half duplex controller with support for TPM wait state detection like
76  * Tegra QSPI need CMD, ADDR & DATA sent in single message to manage HW flow
77  * control. Each phase sent in different transfer for controller to idenity
93 		phy->iobuf[0] = (in ? 0x80 : 0) | (transfer_len - 1);  in tpm_tis_spi_transfer_half()
94 		phy->iobuf[1] = 0xd4;  in tpm_tis_spi_transfer_half()
95 		phy->iobuf[2] = addr >> 8;  in tpm_tis_spi_transfer_half()
96 		phy->iobuf[3] = addr;  in tpm_tis_spi_transfer_half()
100 		spi_xfer[0].tx_buf = phy->iobuf;  in tpm_tis_spi_transfer_half()
104 		spi_xfer[1].tx_buf = phy->iobuf + 1;  in tpm_tis_spi_transfer_half()
109 			spi_xfer[2].tx_buf = &phy->iobuf[4];  in tpm_tis_spi_transfer_half()
111 			memcpy(&phy->iobuf[4], out, transfer_len);  in tpm_tis_spi_transfer_half()
117 			spi_xfer[2].rx_buf = &phy->iobuf[4];  in tpm_tis_spi_transfer_half()
123 		reinit_completion(&phy->ready);  in tpm_tis_spi_transfer_half()
125 		ret = spi_sync(phy->spi_device, &m);  in tpm_tis_spi_transfer_half()
130 			memcpy(in, &phy->iobuf[4], transfer_len);  in tpm_tis_spi_transfer_half()
134 		len -= transfer_len;  in tpm_tis_spi_transfer_half()
149 	spi_bus_lock(phy->spi_device->master);  in tpm_tis_spi_transfer_full()
154 		phy->iobuf[0] = (in ? 0x80 : 0) | (transfer_len - 1);  in tpm_tis_spi_transfer_full()
155 		phy->iobuf[1] = 0xd4;  in tpm_tis_spi_transfer_full()
156 		phy->iobuf[2] = addr >> 8;  in tpm_tis_spi_transfer_full()
157 		phy->iobuf[3] = addr;  in tpm_tis_spi_transfer_full()
160 		spi_xfer.tx_buf = phy->iobuf;  in tpm_tis_spi_transfer_full()
161 		spi_xfer.rx_buf = phy->iobuf;  in tpm_tis_spi_transfer_full()
167 		ret = spi_sync_locked(phy->spi_device, &m);  in tpm_tis_spi_transfer_full()
171 		/* Flow control transfers are receive only */  in tpm_tis_spi_transfer_full()
173 		ret = phy->flow_control(phy, &spi_xfer);  in tpm_tis_spi_transfer_full()
183 			spi_xfer.tx_buf = phy->iobuf;  in tpm_tis_spi_transfer_full()
185 			memcpy(phy->iobuf, out, transfer_len);  in tpm_tis_spi_transfer_full()
191 		reinit_completion(&phy->ready);  in tpm_tis_spi_transfer_full()
192 		ret = spi_sync_locked(phy->spi_device, &m);  in tpm_tis_spi_transfer_full()
197 			memcpy(in, phy->iobuf, transfer_len);  in tpm_tis_spi_transfer_full()
201 		len -= transfer_len;  in tpm_tis_spi_transfer_full()
210 		spi_sync_locked(phy->spi_device, &m);  in tpm_tis_spi_transfer_full()
213 	spi_bus_unlock(phy->spi_device->master);  in tpm_tis_spi_transfer_full()
221 	struct spi_controller *ctlr = phy->spi_device->controller;  in tpm_tis_spi_transfer()
224 	 * TPM flow control over SPI requires full duplex support.  in tpm_tis_spi_transfer()
225 	 * Send entire message to a half duplex controller to handle  in tpm_tis_spi_transfer()
226 	 * wait polling in controller.  in tpm_tis_spi_transfer()
227 	 * Set TPM HW flow control flag..  in tpm_tis_spi_transfer()
229 	if (ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX)  in tpm_tis_spi_transfer()
250 	phy->iobuf = devm_kmalloc(&spi->dev, MAX_SPI_FRAMESIZE, GFP_KERNEL);  in tpm_tis_spi_init()
251 	if (!phy->iobuf)  in tpm_tis_spi_init()
252 		return -ENOMEM;  in tpm_tis_spi_init()
254 	phy->spi_device = spi;  in tpm_tis_spi_init()
256 	return tpm_tis_core_init(&spi->dev, &phy->priv, irq, phy_ops, NULL);  in tpm_tis_spi_init()
269 	phy = devm_kzalloc(&dev->dev, sizeof(struct tpm_tis_spi_phy),  in tpm_tis_spi_probe()
272 		return -ENOMEM;  in tpm_tis_spi_probe()
274 	phy->flow_control = tpm_tis_spi_flow_control;  in tpm_tis_spi_probe()
276 	if (dev->controller->flags & SPI_CONTROLLER_HALF_DUPLEX)  in tpm_tis_spi_probe()
277 		dev->mode |= SPI_TPM_HW_FLOW;  in tpm_tis_spi_probe()
280 	if (dev->irq > 0)  in tpm_tis_spi_probe()
281 		irq = dev->irq;  in tpm_tis_spi_probe()
283 		irq = -1;  in tpm_tis_spi_probe()
285 	init_completion(&phy->ready);  in tpm_tis_spi_probe()
296 	probe_func = of_device_get_match_data(&spi->dev);  in tpm_tis_spi_driver_probe()
299 			probe_func = (tpm_tis_spi_probe_func)spi_dev_id->driver_data;  in tpm_tis_spi_driver_probe()
301 				return -ENODEV;  in tpm_tis_spi_driver_probe()
320 	{ "st33htpm-spi", (unsigned long)tpm_tis_spi_probe },
323 	{ "tpm_tis-spi", (unsigned long)tpm_tis_spi_probe },
330 	{ .compatible = "st,st33htpm-spi", .data = tpm_tis_spi_probe },
332 	{ .compatible = "tcg,tpm_tis-spi", .data = tpm_tis_spi_probe },