aboutsummaryrefslogtreecommitdiff
path: root/drivers/input/touchscreen/mxs-lradc-ts.c
diff options
context:
space:
mode:
authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /drivers/input/touchscreen/mxs-lradc-ts.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
Diffstat (limited to 'drivers/input/touchscreen/mxs-lradc-ts.c')
-rw-r--r--drivers/input/touchscreen/mxs-lradc-ts.c703
1 files changed, 703 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/mxs-lradc-ts.c b/drivers/input/touchscreen/mxs-lradc-ts.c
new file mode 100644
index 000000000..9e36fee38
--- /dev/null
+++ b/drivers/input/touchscreen/mxs-lradc-ts.c
@@ -0,0 +1,703 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Freescale MXS LRADC touchscreen driver
+ *
+ * Copyright (c) 2012 DENX Software Engineering, GmbH.
+ * Copyright (c) 2017 Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
+ *
+ * Authors:
+ * Marek Vasut <marex@denx.de>
+ * Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/mxs-lradc.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+
+static const char * const mxs_lradc_ts_irq_names[] = {
+ "mxs-lradc-touchscreen",
+ "mxs-lradc-channel6",
+ "mxs-lradc-channel7",
+};
+
+/*
+ * Touchscreen handling
+ */
+enum mxs_lradc_ts_plate {
+ LRADC_TOUCH = 0,
+ LRADC_SAMPLE_X,
+ LRADC_SAMPLE_Y,
+ LRADC_SAMPLE_PRESSURE,
+ LRADC_SAMPLE_VALID,
+};
+
+struct mxs_lradc_ts {
+ struct mxs_lradc *lradc;
+ struct device *dev;
+
+ void __iomem *base;
+ /*
+ * When the touchscreen is enabled, we give it two private virtual
+ * channels: #6 and #7. This means that only 6 virtual channels (instead
+ * of 8) will be available for buffered capture.
+ */
+#define TOUCHSCREEN_VCHANNEL1 7
+#define TOUCHSCREEN_VCHANNEL2 6
+
+ struct input_dev *ts_input;
+
+ enum mxs_lradc_ts_plate cur_plate; /* state machine */
+ bool ts_valid;
+ unsigned int ts_x_pos;
+ unsigned int ts_y_pos;
+ unsigned int ts_pressure;
+
+ /* handle touchscreen's physical behaviour */
+ /* samples per coordinate */
+ unsigned int over_sample_cnt;
+ /* time clocks between samples */
+ unsigned int over_sample_delay;
+ /* time in clocks to wait after the plates where switched */
+ unsigned int settling_delay;
+ spinlock_t lock;
+};
+
+struct state_info {
+ u32 mask;
+ u32 bit;
+ u32 x_plate;
+ u32 y_plate;
+ u32 pressure;
+};
+
+static struct state_info info[] = {
+ {LRADC_CTRL0_MX23_PLATE_MASK, LRADC_CTRL0_MX23_TOUCH_DETECT_ENABLE,
+ LRADC_CTRL0_MX23_XP | LRADC_CTRL0_MX23_XM,
+ LRADC_CTRL0_MX23_YP | LRADC_CTRL0_MX23_YM,
+ LRADC_CTRL0_MX23_YP | LRADC_CTRL0_MX23_XM},
+ {LRADC_CTRL0_MX28_PLATE_MASK, LRADC_CTRL0_MX28_TOUCH_DETECT_ENABLE,
+ LRADC_CTRL0_MX28_XPPSW | LRADC_CTRL0_MX28_XNNSW,
+ LRADC_CTRL0_MX28_YPPSW | LRADC_CTRL0_MX28_YNNSW,
+ LRADC_CTRL0_MX28_YPPSW | LRADC_CTRL0_MX28_XNNSW}
+};
+
+static bool mxs_lradc_check_touch_event(struct mxs_lradc_ts *ts)
+{
+ return !!(readl(ts->base + LRADC_STATUS) &
+ LRADC_STATUS_TOUCH_DETECT_RAW);
+}
+
+static void mxs_lradc_map_ts_channel(struct mxs_lradc_ts *ts, unsigned int vch,
+ unsigned int ch)
+{
+ writel(LRADC_CTRL4_LRADCSELECT_MASK(vch),
+ ts->base + LRADC_CTRL4 + STMP_OFFSET_REG_CLR);
+ writel(LRADC_CTRL4_LRADCSELECT(vch, ch),
+ ts->base + LRADC_CTRL4 + STMP_OFFSET_REG_SET);
+}
+
+static void mxs_lradc_setup_ts_channel(struct mxs_lradc_ts *ts, unsigned int ch)
+{
+ /*
+ * prepare for oversampling conversion
+ *
+ * from the datasheet:
+ * "The ACCUMULATE bit in the appropriate channel register
+ * HW_LRADC_CHn must be set to 1 if NUM_SAMPLES is greater then 0;
+ * otherwise, the IRQs will not fire."
+ */
+ writel(LRADC_CH_ACCUMULATE |
+ LRADC_CH_NUM_SAMPLES(ts->over_sample_cnt - 1),
+ ts->base + LRADC_CH(ch));
+
+ /* from the datasheet:
+ * "Software must clear this register in preparation for a
+ * multi-cycle accumulation.
+ */
+ writel(LRADC_CH_VALUE_MASK,
+ ts->base + LRADC_CH(ch) + STMP_OFFSET_REG_CLR);
+
+ /*
+ * prepare the delay/loop unit according to the oversampling count
+ *
+ * from the datasheet:
+ * "The DELAY fields in HW_LRADC_DELAY0, HW_LRADC_DELAY1,
+ * HW_LRADC_DELAY2, and HW_LRADC_DELAY3 must be non-zero; otherwise,
+ * the LRADC will not trigger the delay group."
+ */
+ writel(LRADC_DELAY_TRIGGER(1 << ch) | LRADC_DELAY_TRIGGER_DELAYS(0) |
+ LRADC_DELAY_LOOP(ts->over_sample_cnt - 1) |
+ LRADC_DELAY_DELAY(ts->over_sample_delay - 1),
+ ts->base + LRADC_DELAY(3));
+
+ writel(LRADC_CTRL1_LRADC_IRQ(ch),
+ ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
+
+ /*
+ * after changing the touchscreen plates setting
+ * the signals need some initial time to settle. Start the
+ * SoC's delay unit and start the conversion later
+ * and automatically.
+ */
+ writel(LRADC_DELAY_TRIGGER(0) | LRADC_DELAY_TRIGGER_DELAYS(BIT(3)) |
+ LRADC_DELAY_KICK | LRADC_DELAY_DELAY(ts->settling_delay),
+ ts->base + LRADC_DELAY(2));
+}
+
+/*
+ * Pressure detection is special:
+ * We want to do both required measurements for the pressure detection in
+ * one turn. Use the hardware features to chain both conversions and let the
+ * hardware report one interrupt if both conversions are done
+ */
+static void mxs_lradc_setup_ts_pressure(struct mxs_lradc_ts *ts,
+ unsigned int ch1, unsigned int ch2)
+{
+ u32 reg;
+
+ /*
+ * prepare for oversampling conversion
+ *
+ * from the datasheet:
+ * "The ACCUMULATE bit in the appropriate channel register
+ * HW_LRADC_CHn must be set to 1 if NUM_SAMPLES is greater then 0;
+ * otherwise, the IRQs will not fire."
+ */
+ reg = LRADC_CH_ACCUMULATE |
+ LRADC_CH_NUM_SAMPLES(ts->over_sample_cnt - 1);
+ writel(reg, ts->base + LRADC_CH(ch1));
+ writel(reg, ts->base + LRADC_CH(ch2));
+
+ /* from the datasheet:
+ * "Software must clear this register in preparation for a
+ * multi-cycle accumulation.
+ */
+ writel(LRADC_CH_VALUE_MASK,
+ ts->base + LRADC_CH(ch1) + STMP_OFFSET_REG_CLR);
+ writel(LRADC_CH_VALUE_MASK,
+ ts->base + LRADC_CH(ch2) + STMP_OFFSET_REG_CLR);
+
+ /* prepare the delay/loop unit according to the oversampling count */
+ writel(LRADC_DELAY_TRIGGER(1 << ch1) | LRADC_DELAY_TRIGGER(1 << ch2) |
+ LRADC_DELAY_TRIGGER_DELAYS(0) |
+ LRADC_DELAY_LOOP(ts->over_sample_cnt - 1) |
+ LRADC_DELAY_DELAY(ts->over_sample_delay - 1),
+ ts->base + LRADC_DELAY(3));
+
+ writel(LRADC_CTRL1_LRADC_IRQ(ch2),
+ ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
+
+ /*
+ * after changing the touchscreen plates setting
+ * the signals need some initial time to settle. Start the
+ * SoC's delay unit and start the conversion later
+ * and automatically.
+ */
+ writel(LRADC_DELAY_TRIGGER(0) | LRADC_DELAY_TRIGGER_DELAYS(BIT(3)) |
+ LRADC_DELAY_KICK | LRADC_DELAY_DELAY(ts->settling_delay),
+ ts->base + LRADC_DELAY(2));
+}
+
+static unsigned int mxs_lradc_ts_read_raw_channel(struct mxs_lradc_ts *ts,
+ unsigned int channel)
+{
+ u32 reg;
+ unsigned int num_samples, val;
+
+ reg = readl(ts->base + LRADC_CH(channel));
+ if (reg & LRADC_CH_ACCUMULATE)
+ num_samples = ts->over_sample_cnt;
+ else
+ num_samples = 1;
+
+ val = (reg & LRADC_CH_VALUE_MASK) >> LRADC_CH_VALUE_OFFSET;
+ return val / num_samples;
+}
+
+static unsigned int mxs_lradc_read_ts_pressure(struct mxs_lradc_ts *ts,
+ unsigned int ch1, unsigned int ch2)
+{
+ u32 reg, mask;
+ unsigned int pressure, m1, m2;
+
+ mask = LRADC_CTRL1_LRADC_IRQ(ch1) | LRADC_CTRL1_LRADC_IRQ(ch2);
+ reg = readl(ts->base + LRADC_CTRL1) & mask;
+
+ while (reg != mask) {
+ reg = readl(ts->base + LRADC_CTRL1) & mask;
+ dev_dbg(ts->dev, "One channel is still busy: %X\n", reg);
+ }
+
+ m1 = mxs_lradc_ts_read_raw_channel(ts, ch1);
+ m2 = mxs_lradc_ts_read_raw_channel(ts, ch2);
+
+ if (m2 == 0) {
+ dev_warn(ts->dev, "Cannot calculate pressure\n");
+ return 1 << (LRADC_RESOLUTION - 1);
+ }
+
+ /* simply scale the value from 0 ... max ADC resolution */
+ pressure = m1;
+ pressure *= (1 << LRADC_RESOLUTION);
+ pressure /= m2;
+
+ dev_dbg(ts->dev, "Pressure = %u\n", pressure);
+ return pressure;
+}
+
+#define TS_CH_XP 2
+#define TS_CH_YP 3
+#define TS_CH_XM 4
+#define TS_CH_YM 5
+
+/*
+ * YP(open)--+-------------+
+ * | |--+
+ * | | |
+ * YM(-)--+-------------+ |
+ * +--------------+
+ * | |
+ * XP(weak+) XM(open)
+ *
+ * "weak+" means 200k Ohm VDDIO
+ * (-) means GND
+ */
+static void mxs_lradc_setup_touch_detection(struct mxs_lradc_ts *ts)
+{
+ struct mxs_lradc *lradc = ts->lradc;
+
+ /*
+ * In order to detect a touch event the 'touch detect enable' bit
+ * enables:
+ * - a weak pullup to the X+ connector
+ * - a strong ground at the Y- connector
+ */
+ writel(info[lradc->soc].mask,
+ ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
+ writel(info[lradc->soc].bit,
+ ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET);
+}
+
+/*
+ * YP(meas)--+-------------+
+ * | |--+
+ * | | |
+ * YM(open)--+-------------+ |
+ * +--------------+
+ * | |
+ * XP(+) XM(-)
+ *
+ * (+) means here 1.85 V
+ * (-) means here GND
+ */
+static void mxs_lradc_prepare_x_pos(struct mxs_lradc_ts *ts)
+{
+ struct mxs_lradc *lradc = ts->lradc;
+
+ writel(info[lradc->soc].mask,
+ ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
+ writel(info[lradc->soc].x_plate,
+ ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET);
+
+ ts->cur_plate = LRADC_SAMPLE_X;
+ mxs_lradc_map_ts_channel(ts, TOUCHSCREEN_VCHANNEL1, TS_CH_YP);
+ mxs_lradc_setup_ts_channel(ts, TOUCHSCREEN_VCHANNEL1);
+}
+
+/*
+ * YP(+)--+-------------+
+ * | |--+
+ * | | |
+ * YM(-)--+-------------+ |
+ * +--------------+
+ * | |
+ * XP(open) XM(meas)
+ *
+ * (+) means here 1.85 V
+ * (-) means here GND
+ */
+static void mxs_lradc_prepare_y_pos(struct mxs_lradc_ts *ts)
+{
+ struct mxs_lradc *lradc = ts->lradc;
+
+ writel(info[lradc->soc].mask,
+ ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
+ writel(info[lradc->soc].y_plate,
+ ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET);
+
+ ts->cur_plate = LRADC_SAMPLE_Y;
+ mxs_lradc_map_ts_channel(ts, TOUCHSCREEN_VCHANNEL1, TS_CH_XM);
+ mxs_lradc_setup_ts_channel(ts, TOUCHSCREEN_VCHANNEL1);
+}
+
+/*
+ * YP(+)--+-------------+
+ * | |--+
+ * | | |
+ * YM(meas)--+-------------+ |
+ * +--------------+
+ * | |
+ * XP(meas) XM(-)
+ *
+ * (+) means here 1.85 V
+ * (-) means here GND
+ */
+static void mxs_lradc_prepare_pressure(struct mxs_lradc_ts *ts)
+{
+ struct mxs_lradc *lradc = ts->lradc;
+
+ writel(info[lradc->soc].mask,
+ ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
+ writel(info[lradc->soc].pressure,
+ ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET);
+
+ ts->cur_plate = LRADC_SAMPLE_PRESSURE;
+ mxs_lradc_map_ts_channel(ts, TOUCHSCREEN_VCHANNEL1, TS_CH_YM);
+ mxs_lradc_map_ts_channel(ts, TOUCHSCREEN_VCHANNEL2, TS_CH_XP);
+ mxs_lradc_setup_ts_pressure(ts, TOUCHSCREEN_VCHANNEL2,
+ TOUCHSCREEN_VCHANNEL1);
+}
+
+static void mxs_lradc_enable_touch_detection(struct mxs_lradc_ts *ts)
+{
+ mxs_lradc_setup_touch_detection(ts);
+
+ ts->cur_plate = LRADC_TOUCH;
+ writel(LRADC_CTRL1_TOUCH_DETECT_IRQ | LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
+ ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
+ writel(LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
+ ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_SET);
+}
+
+static void mxs_lradc_start_touch_event(struct mxs_lradc_ts *ts)
+{
+ writel(LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
+ ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
+ writel(LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1),
+ ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_SET);
+ /*
+ * start with the Y-pos, because it uses nearly the same plate
+ * settings like the touch detection
+ */
+ mxs_lradc_prepare_y_pos(ts);
+}
+
+static void mxs_lradc_report_ts_event(struct mxs_lradc_ts *ts)
+{
+ input_report_abs(ts->ts_input, ABS_X, ts->ts_x_pos);
+ input_report_abs(ts->ts_input, ABS_Y, ts->ts_y_pos);
+ input_report_abs(ts->ts_input, ABS_PRESSURE, ts->ts_pressure);
+ input_report_key(ts->ts_input, BTN_TOUCH, 1);
+ input_sync(ts->ts_input);
+}
+
+static void mxs_lradc_complete_touch_event(struct mxs_lradc_ts *ts)
+{
+ mxs_lradc_setup_touch_detection(ts);
+ ts->cur_plate = LRADC_SAMPLE_VALID;
+ /*
+ * start a dummy conversion to burn time to settle the signals
+ * note: we are not interested in the conversion's value
+ */
+ writel(0, ts->base + LRADC_CH(TOUCHSCREEN_VCHANNEL1));
+ writel(LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1) |
+ LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL2),
+ ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
+ writel(LRADC_DELAY_TRIGGER(1 << TOUCHSCREEN_VCHANNEL1) |
+ LRADC_DELAY_KICK | LRADC_DELAY_DELAY(10),
+ ts->base + LRADC_DELAY(2));
+}
+
+/*
+ * in order to avoid false measurements, report only samples where
+ * the surface is still touched after the position measurement
+ */
+static void mxs_lradc_finish_touch_event(struct mxs_lradc_ts *ts, bool valid)
+{
+ /* if it is still touched, report the sample */
+ if (valid && mxs_lradc_check_touch_event(ts)) {
+ ts->ts_valid = true;
+ mxs_lradc_report_ts_event(ts);
+ }
+
+ /* if it is even still touched, continue with the next measurement */
+ if (mxs_lradc_check_touch_event(ts)) {
+ mxs_lradc_prepare_y_pos(ts);
+ return;
+ }
+
+ if (ts->ts_valid) {
+ /* signal the release */
+ ts->ts_valid = false;
+ input_report_key(ts->ts_input, BTN_TOUCH, 0);
+ input_sync(ts->ts_input);
+ }
+
+ /* if it is released, wait for the next touch via IRQ */
+ ts->cur_plate = LRADC_TOUCH;
+ writel(0, ts->base + LRADC_DELAY(2));
+ writel(0, ts->base + LRADC_DELAY(3));
+ writel(LRADC_CTRL1_TOUCH_DETECT_IRQ |
+ LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1) |
+ LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1),
+ ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
+ writel(LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
+ ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_SET);
+}
+
+/* touchscreen's state machine */
+static void mxs_lradc_handle_touch(struct mxs_lradc_ts *ts)
+{
+ switch (ts->cur_plate) {
+ case LRADC_TOUCH:
+ if (mxs_lradc_check_touch_event(ts))
+ mxs_lradc_start_touch_event(ts);
+ writel(LRADC_CTRL1_TOUCH_DETECT_IRQ,
+ ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
+ return;
+
+ case LRADC_SAMPLE_Y:
+ ts->ts_y_pos =
+ mxs_lradc_ts_read_raw_channel(ts, TOUCHSCREEN_VCHANNEL1);
+ mxs_lradc_prepare_x_pos(ts);
+ return;
+
+ case LRADC_SAMPLE_X:
+ ts->ts_x_pos =
+ mxs_lradc_ts_read_raw_channel(ts, TOUCHSCREEN_VCHANNEL1);
+ mxs_lradc_prepare_pressure(ts);
+ return;
+
+ case LRADC_SAMPLE_PRESSURE:
+ ts->ts_pressure =
+ mxs_lradc_read_ts_pressure(ts,
+ TOUCHSCREEN_VCHANNEL2,
+ TOUCHSCREEN_VCHANNEL1);
+ mxs_lradc_complete_touch_event(ts);
+ return;
+
+ case LRADC_SAMPLE_VALID:
+ mxs_lradc_finish_touch_event(ts, 1);
+ break;
+ }
+}
+
+/* IRQ Handling */
+static irqreturn_t mxs_lradc_ts_handle_irq(int irq, void *data)
+{
+ struct mxs_lradc_ts *ts = data;
+ struct mxs_lradc *lradc = ts->lradc;
+ unsigned long reg = readl(ts->base + LRADC_CTRL1);
+ u32 clr_irq = mxs_lradc_irq_mask(lradc);
+ const u32 ts_irq_mask =
+ LRADC_CTRL1_TOUCH_DETECT_IRQ |
+ LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1) |
+ LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL2);
+ unsigned long flags;
+
+ if (!(reg & mxs_lradc_irq_mask(lradc)))
+ return IRQ_NONE;
+
+ if (reg & ts_irq_mask) {
+ spin_lock_irqsave(&ts->lock, flags);
+ mxs_lradc_handle_touch(ts);
+ spin_unlock_irqrestore(&ts->lock, flags);
+ /* Make sure we don't clear the next conversion's interrupt. */
+ clr_irq &= ~(LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1) |
+ LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL2));
+ writel(reg & clr_irq,
+ ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int mxs_lradc_ts_open(struct input_dev *dev)
+{
+ struct mxs_lradc_ts *ts = input_get_drvdata(dev);
+
+ /* Enable the touch-detect circuitry. */
+ mxs_lradc_enable_touch_detection(ts);
+
+ return 0;
+}
+
+static void mxs_lradc_ts_stop(struct mxs_lradc_ts *ts)
+{
+ int i;
+ struct mxs_lradc *lradc = ts->lradc;
+
+ /* stop all interrupts from firing */
+ writel(LRADC_CTRL1_TOUCH_DETECT_IRQ_EN |
+ LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1) |
+ LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL2),
+ ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
+
+ /* Power-down touchscreen touch-detect circuitry. */
+ writel(info[lradc->soc].mask,
+ ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
+
+ writel(lradc->buffer_vchans << LRADC_CTRL1_LRADC_IRQ_EN_OFFSET,
+ ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
+
+ for (i = 1; i < LRADC_MAX_DELAY_CHANS; i++)
+ writel(0, ts->base + LRADC_DELAY(i));
+}
+
+static void mxs_lradc_ts_close(struct input_dev *dev)
+{
+ struct mxs_lradc_ts *ts = input_get_drvdata(dev);
+
+ mxs_lradc_ts_stop(ts);
+}
+
+static void mxs_lradc_ts_hw_init(struct mxs_lradc_ts *ts)
+{
+ struct mxs_lradc *lradc = ts->lradc;
+
+ /* Configure the touchscreen type */
+ if (lradc->soc == IMX28_LRADC) {
+ writel(LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE,
+ ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
+
+ if (lradc->touchscreen_wire == MXS_LRADC_TOUCHSCREEN_5WIRE)
+ writel(LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE,
+ ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET);
+ }
+}
+
+static int mxs_lradc_ts_register(struct mxs_lradc_ts *ts)
+{
+ struct input_dev *input;
+ struct device *dev = ts->dev;
+
+ input = devm_input_allocate_device(dev);
+ if (!input)
+ return -ENOMEM;
+
+ input->name = "mxs-lradc-ts";
+ input->id.bustype = BUS_HOST;
+ input->open = mxs_lradc_ts_open;
+ input->close = mxs_lradc_ts_close;
+
+ __set_bit(INPUT_PROP_DIRECT, input->propbit);
+ input_set_capability(input, EV_KEY, BTN_TOUCH);
+ input_set_abs_params(input, ABS_X, 0, LRADC_SINGLE_SAMPLE_MASK, 0, 0);
+ input_set_abs_params(input, ABS_Y, 0, LRADC_SINGLE_SAMPLE_MASK, 0, 0);
+ input_set_abs_params(input, ABS_PRESSURE, 0, LRADC_SINGLE_SAMPLE_MASK,
+ 0, 0);
+
+ ts->ts_input = input;
+ input_set_drvdata(input, ts);
+
+ return input_register_device(input);
+}
+
+static int mxs_lradc_ts_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *node = dev->parent->of_node;
+ struct mxs_lradc *lradc = dev_get_drvdata(dev->parent);
+ struct mxs_lradc_ts *ts;
+ int ret, irq, virq, i;
+ u32 ts_wires = 0, adapt;
+
+ ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
+ if (!ts)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, ts);
+
+ ts->lradc = lradc;
+ ts->dev = dev;
+ spin_lock_init(&ts->lock);
+
+ ts->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(ts->base))
+ return PTR_ERR(ts->base);
+
+ ret = of_property_read_u32(node, "fsl,lradc-touchscreen-wires",
+ &ts_wires);
+ if (ret)
+ return ret;
+
+ if (of_property_read_u32(node, "fsl,ave-ctrl", &adapt)) {
+ ts->over_sample_cnt = 4;
+ } else {
+ if (adapt >= 1 && adapt <= 32) {
+ ts->over_sample_cnt = adapt;
+ } else {
+ dev_err(ts->dev, "Invalid sample count (%u)\n",
+ adapt);
+ return -EINVAL;
+ }
+ }
+
+ if (of_property_read_u32(node, "fsl,ave-delay", &adapt)) {
+ ts->over_sample_delay = 2;
+ } else {
+ if (adapt >= 2 && adapt <= LRADC_DELAY_DELAY_MASK + 1) {
+ ts->over_sample_delay = adapt;
+ } else {
+ dev_err(ts->dev, "Invalid sample delay (%u)\n",
+ adapt);
+ return -EINVAL;
+ }
+ }
+
+ if (of_property_read_u32(node, "fsl,settling", &adapt)) {
+ ts->settling_delay = 10;
+ } else {
+ if (adapt >= 1 && adapt <= LRADC_DELAY_DELAY_MASK) {
+ ts->settling_delay = adapt;
+ } else {
+ dev_err(ts->dev, "Invalid settling delay (%u)\n",
+ adapt);
+ return -EINVAL;
+ }
+ }
+
+ ret = stmp_reset_block(ts->base);
+ if (ret)
+ return ret;
+
+ mxs_lradc_ts_hw_init(ts);
+
+ for (i = 0; i < 3; i++) {
+ irq = platform_get_irq_byname(pdev, mxs_lradc_ts_irq_names[i]);
+ if (irq < 0)
+ return irq;
+
+ virq = irq_of_parse_and_map(node, irq);
+
+ mxs_lradc_ts_stop(ts);
+
+ ret = devm_request_irq(dev, virq,
+ mxs_lradc_ts_handle_irq,
+ 0, mxs_lradc_ts_irq_names[i], ts);
+ if (ret)
+ return ret;
+ }
+
+ return mxs_lradc_ts_register(ts);
+}
+
+static struct platform_driver mxs_lradc_ts_driver = {
+ .driver = {
+ .name = "mxs-lradc-ts",
+ },
+ .probe = mxs_lradc_ts_probe,
+};
+module_platform_driver(mxs_lradc_ts_driver);
+
+MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
+MODULE_DESCRIPTION("Freescale MXS LRADC touchscreen driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:mxs-lradc-ts");