drivers/i2c/meson_i2c.c

10 #include <i2c.h>
64 static void meson_i2c_reset_tokens(struct meson_i2c *i2c)
66 	i2c->tokens[0] = 0;
67 	i2c->tokens[1] = 0;
68 	i2c->num_tokens = 0;
71 static void meson_i2c_add_token(struct meson_i2c *i2c, int token)
73 	if (i2c->num_tokens < 8)
74 		i2c->tokens[0] |= (token & 0xf) << (i2c->num_tokens * 4);
76 		i2c->tokens[1] |= (token & 0xf) << ((i2c->num_tokens % 8) * 4);
78 	i2c->num_tokens++;
85 static void meson_i2c_get_data(struct meson_i2c *i2c, u8 *buf, int len)
90 	rdata0 = readl(&i2c->regs->tok_rdata0);
91 	rdata1 = readl(&i2c->regs->tok_rdata1);
93 	debug("meson i2c: read data %08x %08x len %d\n", rdata0, rdata1, len);
106 static void meson_i2c_put_data(struct meson_i2c *i2c, u8 *buf, int len)
117 	writel(wdata0, &i2c->regs->tok_wdata0);
118 	writel(wdata1, &i2c->regs->tok_wdata1);
120 	debug("meson i2c: write data %08x %08x len %d\n", wdata0, wdata1, len);
128 static void meson_i2c_prepare_xfer(struct meson_i2c *i2c)
130 	bool write = !(i2c->msg->flags & I2C_M_RD);
133 	i2c->count = min(i2c->msg->len - i2c->pos, 8u);
135 	for (i = 0; i + 1 < i2c->count; i++)
136 		meson_i2c_add_token(i2c, TOKEN_DATA);
138 	if (i2c->count) {
139 		if (write || i2c->pos + i2c->count < i2c->msg->len)
140 			meson_i2c_add_token(i2c, TOKEN_DATA);
142 			meson_i2c_add_token(i2c, TOKEN_DATA_LAST);
146 		meson_i2c_put_data(i2c, i2c->msg->buf + i2c->pos, i2c->count);
148 	if (i2c->last && i2c->pos + i2c->count >= i2c->msg->len)
149 		meson_i2c_add_token(i2c, TOKEN_STOP);
151 	writel(i2c->tokens[0], &i2c->regs->tok_list0);
152 	writel(i2c->tokens[1], &i2c->regs->tok_list1);
155 static void meson_i2c_do_start(struct meson_i2c *i2c, struct i2c_msg *msg)
162 	writel(msg->addr << 1, &i2c->regs->slave_addr);
163 	meson_i2c_add_token(i2c, TOKEN_START);
164 	meson_i2c_add_token(i2c, token);
167 static int meson_i2c_xfer_msg(struct meson_i2c *i2c, struct i2c_msg *msg,
172 	debug("meson i2c: %s addr %u len %u\n",
176 	i2c->msg = msg;
177 	i2c->last = last;
178 	i2c->pos = 0;
179 	i2c->count = 0;
181 	meson_i2c_reset_tokens(i2c);
182 	meson_i2c_do_start(i2c, msg);
185 		meson_i2c_prepare_xfer(i2c);
188 		setbits_le32(&i2c->regs->ctrl, REG_CTRL_START);
190 		while (readl(&i2c->regs->ctrl) & REG_CTRL_STATUS) {
192 				clrbits_le32(&i2c->regs->ctrl, REG_CTRL_START);
193 				debug("meson i2c: timeout\n");
198 		meson_i2c_reset_tokens(i2c);
199 		clrbits_le32(&i2c->regs->ctrl, REG_CTRL_START);
201 		if (readl(&i2c->regs->ctrl) & REG_CTRL_ERROR) {
202 			debug("meson i2c: error\n");
206 		if ((msg->flags & I2C_M_RD) && i2c->count) {
207 			meson_i2c_get_data(i2c, i2c->msg->buf + i2c->pos,
208 					   i2c->count);
210 		i2c->pos += i2c->count;
211 	} while (i2c->pos < msg->len);
219 	struct meson_i2c *i2c = dev_get_priv(bus);
223 		ret = meson_i2c_xfer_msg(i2c, msg + i, i == nmsgs - 1);
233 	struct meson_i2c *i2c = dev_get_priv(bus);
237 	clk_rate = clk_get_rate(&i2c->clk);
241 	div = DIV_ROUND_UP(clk_rate, speed * i2c->data->div_factor);
245 		debug("meson i2c: requested bus frequency too low\n");
249 	clrsetbits_le32(&i2c->regs->ctrl, REG_CTRL_CLKDIV_MASK,
252 	clrsetbits_le32(&i2c->regs->ctrl, REG_CTRL_CLKDIVEXT_MASK,
255 	debug("meson i2c: set clk %u, src %lu, div %u\n", speed, clk_rate, div);
262 	struct meson_i2c *i2c = dev_get_priv(bus);
265 	i2c->data = (const struct meson_i2c_data *)dev_get_driver_data(bus);
267 	ret = clk_get_by_index(bus, 0, &i2c->clk);
271 	ret = clk_enable(&i2c->clk);
275 	i2c->regs = dev_read_addr_ptr(bus);
276 	clrbits_le32(&i2c->regs->ctrl, REG_CTRL_START);
299 	{.compatible = "amlogic,meson6-i2c", .data = (ulong)&i2c_meson6_data},
300 	{.compatible = "amlogic,meson-gx-i2c", .data = (ulong)&i2c_gxbb_data},
301 	{.compatible = "amlogic,meson-gxbb-i2c", .data = (ulong)&i2c_gxbb_data},
302 	{.compatible = "amlogic,meson-axg-i2c", .data = (ulong)&i2c_axg_data},