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author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-06-24 16:49:49 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-06-24 16:49:49 -0700 |
commit | e0456717e483bb8a9431b80a5bdc99a928b9b003 (patch) | |
tree | 5eb5add2bafd1f20326d70f5cb3b711d00a40b10 /drivers/nfc/st-nci/i2c.c | |
parent | 98ec21a01896751b673b6c731ca8881daa8b2c6d (diff) | |
parent | 1ea2d020ba477cb7011a7174e8501a9e04a325d4 (diff) | |
download | linux-e0456717e483bb8a9431b80a5bdc99a928b9b003.tar.bz2 |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:
1) Add TX fast path in mac80211, from Johannes Berg.
2) Add TSO/GRO support to ibmveth, from Thomas Falcon
3) Move away from cached routes in ipv6, just like ipv4, from Martin
KaFai Lau.
4) Lots of new rhashtable tests, from Thomas Graf.
5) Run ingress qdisc lockless, from Alexei Starovoitov.
6) Allow servers to fetch TCP packet headers for SYN packets of new
connections, for fingerprinting. From Eric Dumazet.
7) Add mode parameter to pktgen, for testing receive. From Alexei
Starovoitov.
8) Cache access optimizations via simplifications of build_skb(), from
Alexander Duyck.
9) Move page frag allocator under mm/, also from Alexander.
10) Add xmit_more support to hv_netvsc, from KY Srinivasan.
11) Add a counter guard in case we try to perform endless reclassify
loops in the packet scheduler.
12) Extern flow dissector to be programmable and use it in new "Flower"
classifier. From Jiri Pirko.
13) AF_PACKET fanout rollover fixes, performance improvements, and new
statistics. From Willem de Bruijn.
14) Add netdev driver for GENEVE tunnels, from John W Linville.
15) Add ingress netfilter hooks and filtering, from Pablo Neira Ayuso.
16) Fix handling of epoll edge triggers in TCP, from Eric Dumazet.
17) Add an ECN retry fallback for the initial TCP handshake, from Daniel
Borkmann.
18) Add tail call support to BPF, from Alexei Starovoitov.
19) Add several pktgen helper scripts, from Jesper Dangaard Brouer.
20) Add zerocopy support to AF_UNIX, from Hannes Frederic Sowa.
21) Favor even port numbers for allocation to connect() requests, and
odd port numbers for bind(0), in an effort to help avoid
ip_local_port_range exhaustion. From Eric Dumazet.
22) Add Cavium ThunderX driver, from Sunil Goutham.
23) Allow bpf programs to access skb_iif and dev->ifindex SKB metadata,
from Alexei Starovoitov.
24) Add support for T6 chips in cxgb4vf driver, from Hariprasad Shenai.
25) Double TCP Small Queues default to 256K to accomodate situations
like the XEN driver and wireless aggregation. From Wei Liu.
26) Add more entropy inputs to flow dissector, from Tom Herbert.
27) Add CDG congestion control algorithm to TCP, from Kenneth Klette
Jonassen.
28) Convert ipset over to RCU locking, from Jozsef Kadlecsik.
29) Track and act upon link status of ipv4 route nexthops, from Andy
Gospodarek.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1670 commits)
bridge: vlan: flush the dynamically learned entries on port vlan delete
bridge: multicast: add a comment to br_port_state_selection about blocking state
net: inet_diag: export IPV6_V6ONLY sockopt
stmmac: troubleshoot unexpected bits in des0 & des1
net: ipv4 sysctl option to ignore routes when nexthop link is down
net: track link-status of ipv4 nexthops
net: switchdev: ignore unsupported bridge flags
net: Cavium: Fix MAC address setting in shutdown state
drivers: net: xgene: fix for ACPI support without ACPI
ip: report the original address of ICMP messages
net/mlx5e: Prefetch skb data on RX
net/mlx5e: Pop cq outside mlx5e_get_cqe
net/mlx5e: Remove mlx5e_cq.sqrq back-pointer
net/mlx5e: Remove extra spaces
net/mlx5e: Avoid TX CQE generation if more xmit packets expected
net/mlx5e: Avoid redundant dev_kfree_skb() upon NOP completion
net/mlx5e: Remove re-assignment of wq type in mlx5e_enable_rq()
net/mlx5e: Use skb_shinfo(skb)->gso_segs rather than counting them
net/mlx5e: Static mapping of netdev priv resources to/from netdev TX queues
net/mlx4_en: Use HW counters for rx/tx bytes/packets in PF device
...
Diffstat (limited to 'drivers/nfc/st-nci/i2c.c')
-rw-r--r-- | drivers/nfc/st-nci/i2c.c | 385 |
1 files changed, 385 insertions, 0 deletions
diff --git a/drivers/nfc/st-nci/i2c.c b/drivers/nfc/st-nci/i2c.c new file mode 100644 index 000000000000..06175ce769bb --- /dev/null +++ b/drivers/nfc/st-nci/i2c.c @@ -0,0 +1,385 @@ +/* + * I2C Link Layer for ST NCI NFC controller familly based Driver + * Copyright (C) 2014-2015 STMicroelectronics SAS. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/i2c.h> +#include <linux/gpio.h> +#include <linux/of_irq.h> +#include <linux/of_gpio.h> +#include <linux/interrupt.h> +#include <linux/delay.h> +#include <linux/nfc.h> +#include <linux/platform_data/st_nci.h> + +#include "ndlc.h" + +#define DRIVER_DESC "NCI NFC driver for ST21NFCB" + +/* ndlc header */ +#define ST21NFCB_FRAME_HEADROOM 1 +#define ST21NFCB_FRAME_TAILROOM 0 + +#define ST_NCI_I2C_MIN_SIZE 4 /* PCB(1) + NCI Packet header(3) */ +#define ST_NCI_I2C_MAX_SIZE 250 /* req 4.2.1 */ + +#define ST_NCI_I2C_DRIVER_NAME "st_nci_i2c" + +static struct i2c_device_id st_nci_i2c_id_table[] = { + {ST_NCI_DRIVER_NAME, 0}, + {} +}; +MODULE_DEVICE_TABLE(i2c, st_nci_i2c_id_table); + +struct st_nci_i2c_phy { + struct i2c_client *i2c_dev; + struct llt_ndlc *ndlc; + + unsigned int gpio_reset; + unsigned int irq_polarity; +}; + +#define I2C_DUMP_SKB(info, skb) \ +do { \ + pr_debug("%s:\n", info); \ + print_hex_dump(KERN_DEBUG, "i2c: ", DUMP_PREFIX_OFFSET, \ + 16, 1, (skb)->data, (skb)->len, 0); \ +} while (0) + +static int st_nci_i2c_enable(void *phy_id) +{ + struct st_nci_i2c_phy *phy = phy_id; + + gpio_set_value(phy->gpio_reset, 0); + usleep_range(10000, 15000); + gpio_set_value(phy->gpio_reset, 1); + usleep_range(80000, 85000); + + if (phy->ndlc->powered == 0) + enable_irq(phy->i2c_dev->irq); + + return 0; +} + +static void st_nci_i2c_disable(void *phy_id) +{ + struct st_nci_i2c_phy *phy = phy_id; + + disable_irq_nosync(phy->i2c_dev->irq); +} + +/* + * Writing a frame must not return the number of written bytes. + * It must return either zero for success, or <0 for error. + * In addition, it must not alter the skb + */ +static int st_nci_i2c_write(void *phy_id, struct sk_buff *skb) +{ + int r = -1; + struct st_nci_i2c_phy *phy = phy_id; + struct i2c_client *client = phy->i2c_dev; + + I2C_DUMP_SKB("st_nci_i2c_write", skb); + + if (phy->ndlc->hard_fault != 0) + return phy->ndlc->hard_fault; + + r = i2c_master_send(client, skb->data, skb->len); + if (r < 0) { /* Retry, chip was in standby */ + usleep_range(1000, 4000); + r = i2c_master_send(client, skb->data, skb->len); + } + + if (r >= 0) { + if (r != skb->len) + r = -EREMOTEIO; + else + r = 0; + } + + return r; +} + +/* + * Reads an ndlc frame and returns it in a newly allocated sk_buff. + * returns: + * frame size : if received frame is complete (find ST21NFCB_SOF_EOF at + * end of read) + * -EAGAIN : if received frame is incomplete (not find ST21NFCB_SOF_EOF + * at end of read) + * -EREMOTEIO : i2c read error (fatal) + * -EBADMSG : frame was incorrect and discarded + * (value returned from st_nci_i2c_repack) + * -EIO : if no ST21NFCB_SOF_EOF is found after reaching + * the read length end sequence + */ +static int st_nci_i2c_read(struct st_nci_i2c_phy *phy, + struct sk_buff **skb) +{ + int r; + u8 len; + u8 buf[ST_NCI_I2C_MAX_SIZE]; + struct i2c_client *client = phy->i2c_dev; + + r = i2c_master_recv(client, buf, ST_NCI_I2C_MIN_SIZE); + if (r < 0) { /* Retry, chip was in standby */ + usleep_range(1000, 4000); + r = i2c_master_recv(client, buf, ST_NCI_I2C_MIN_SIZE); + } + + if (r != ST_NCI_I2C_MIN_SIZE) + return -EREMOTEIO; + + len = be16_to_cpu(*(__be16 *) (buf + 2)); + if (len > ST_NCI_I2C_MAX_SIZE) { + nfc_err(&client->dev, "invalid frame len\n"); + return -EBADMSG; + } + + *skb = alloc_skb(ST_NCI_I2C_MIN_SIZE + len, GFP_KERNEL); + if (*skb == NULL) + return -ENOMEM; + + skb_reserve(*skb, ST_NCI_I2C_MIN_SIZE); + skb_put(*skb, ST_NCI_I2C_MIN_SIZE); + memcpy((*skb)->data, buf, ST_NCI_I2C_MIN_SIZE); + + if (!len) + return 0; + + r = i2c_master_recv(client, buf, len); + if (r != len) { + kfree_skb(*skb); + return -EREMOTEIO; + } + + skb_put(*skb, len); + memcpy((*skb)->data + ST_NCI_I2C_MIN_SIZE, buf, len); + + I2C_DUMP_SKB("i2c frame read", *skb); + + return 0; +} + +/* + * Reads an ndlc frame from the chip. + * + * On ST21NFCB, IRQ goes in idle state when read starts. + */ +static irqreturn_t st_nci_irq_thread_fn(int irq, void *phy_id) +{ + struct st_nci_i2c_phy *phy = phy_id; + struct i2c_client *client; + struct sk_buff *skb = NULL; + int r; + + if (!phy || !phy->ndlc || irq != phy->i2c_dev->irq) { + WARN_ON_ONCE(1); + return IRQ_NONE; + } + + client = phy->i2c_dev; + dev_dbg(&client->dev, "IRQ\n"); + + if (phy->ndlc->hard_fault) + return IRQ_HANDLED; + + if (!phy->ndlc->powered) { + st_nci_i2c_disable(phy); + return IRQ_HANDLED; + } + + r = st_nci_i2c_read(phy, &skb); + if (r == -EREMOTEIO || r == -ENOMEM || r == -EBADMSG) + return IRQ_HANDLED; + + ndlc_recv(phy->ndlc, skb); + + return IRQ_HANDLED; +} + +static struct nfc_phy_ops i2c_phy_ops = { + .write = st_nci_i2c_write, + .enable = st_nci_i2c_enable, + .disable = st_nci_i2c_disable, +}; + +#ifdef CONFIG_OF +static int st_nci_i2c_of_request_resources(struct i2c_client *client) +{ + struct st_nci_i2c_phy *phy = i2c_get_clientdata(client); + struct device_node *pp; + int gpio; + int r; + + pp = client->dev.of_node; + if (!pp) + return -ENODEV; + + /* Get GPIO from device tree */ + gpio = of_get_named_gpio(pp, "reset-gpios", 0); + if (gpio < 0) { + nfc_err(&client->dev, + "Failed to retrieve reset-gpios from device tree\n"); + return gpio; + } + + /* GPIO request and configuration */ + r = devm_gpio_request_one(&client->dev, gpio, + GPIOF_OUT_INIT_HIGH, "clf_reset"); + if (r) { + nfc_err(&client->dev, "Failed to request reset pin\n"); + return r; + } + phy->gpio_reset = gpio; + + phy->irq_polarity = irq_get_trigger_type(client->irq); + + return 0; +} +#else +static int st_nci_i2c_of_request_resources(struct i2c_client *client) +{ + return -ENODEV; +} +#endif + +static int st_nci_i2c_request_resources(struct i2c_client *client) +{ + struct st_nci_nfc_platform_data *pdata; + struct st_nci_i2c_phy *phy = i2c_get_clientdata(client); + int r; + + pdata = client->dev.platform_data; + if (pdata == NULL) { + nfc_err(&client->dev, "No platform data\n"); + return -EINVAL; + } + + /* store for later use */ + phy->gpio_reset = pdata->gpio_reset; + phy->irq_polarity = pdata->irq_polarity; + + r = devm_gpio_request_one(&client->dev, + phy->gpio_reset, GPIOF_OUT_INIT_HIGH, "clf_reset"); + if (r) { + pr_err("%s : reset gpio_request failed\n", __FILE__); + return r; + } + + return 0; +} + +static int st_nci_i2c_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct st_nci_i2c_phy *phy; + struct st_nci_nfc_platform_data *pdata; + int r; + + dev_dbg(&client->dev, "%s\n", __func__); + dev_dbg(&client->dev, "IRQ: %d\n", client->irq); + + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { + nfc_err(&client->dev, "Need I2C_FUNC_I2C\n"); + return -ENODEV; + } + + phy = devm_kzalloc(&client->dev, sizeof(struct st_nci_i2c_phy), + GFP_KERNEL); + if (!phy) + return -ENOMEM; + + phy->i2c_dev = client; + + i2c_set_clientdata(client, phy); + + pdata = client->dev.platform_data; + if (!pdata && client->dev.of_node) { + r = st_nci_i2c_of_request_resources(client); + if (r) { + nfc_err(&client->dev, "No platform data\n"); + return r; + } + } else if (pdata) { + r = st_nci_i2c_request_resources(client); + if (r) { + nfc_err(&client->dev, + "Cannot get platform resources\n"); + return r; + } + } else { + nfc_err(&client->dev, + "st21nfcb platform resources not available\n"); + return -ENODEV; + } + + r = ndlc_probe(phy, &i2c_phy_ops, &client->dev, + ST21NFCB_FRAME_HEADROOM, ST21NFCB_FRAME_TAILROOM, + &phy->ndlc); + if (r < 0) { + nfc_err(&client->dev, "Unable to register ndlc layer\n"); + return r; + } + + r = devm_request_threaded_irq(&client->dev, client->irq, NULL, + st_nci_irq_thread_fn, + phy->irq_polarity | IRQF_ONESHOT, + ST_NCI_DRIVER_NAME, phy); + if (r < 0) + nfc_err(&client->dev, "Unable to register IRQ handler\n"); + + return r; +} + +static int st_nci_i2c_remove(struct i2c_client *client) +{ + struct st_nci_i2c_phy *phy = i2c_get_clientdata(client); + + dev_dbg(&client->dev, "%s\n", __func__); + + ndlc_remove(phy->ndlc); + + return 0; +} + +#ifdef CONFIG_OF +static const struct of_device_id of_st_nci_i2c_match[] = { + { .compatible = "st,st21nfcb-i2c", }, + { .compatible = "st,st21nfcb_i2c", }, + { .compatible = "st,st21nfcc-i2c", }, + {} +}; +MODULE_DEVICE_TABLE(of, of_st_nci_i2c_match); +#endif + +static struct i2c_driver st_nci_i2c_driver = { + .driver = { + .owner = THIS_MODULE, + .name = ST_NCI_I2C_DRIVER_NAME, + .of_match_table = of_match_ptr(of_st_nci_i2c_match), + }, + .probe = st_nci_i2c_probe, + .id_table = st_nci_i2c_id_table, + .remove = st_nci_i2c_remove, +}; + +module_i2c_driver(st_nci_i2c_driver); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION(DRIVER_DESC); |